Oracle® Database Gateway forTeradata · Teradata LONG VARCHAR Data Type..... 2-13 Schema Names and...

76
Oracle® Database Gateway for Teradata User’s Guide 12c Release 1 (12.1) E17934-04 April 2013

Transcript of Oracle® Database Gateway forTeradata · Teradata LONG VARCHAR Data Type..... 2-13 Schema Names and...

Oracle® Database Gateway for TeradataUser’s Guide

12c Release 1 (12.1)

E17934-04

April 2013

Oracle Database Gateway for Teradata User's Guide, 12c Release 1 (12.1)

E17934-04

Copyright © 2002, 2013, Oracle and/or its affiliates. All rights reserved.

Primary Author: Maitreyee Chaliha

Contributor: Vira Goorah, Juan Pablo Ahues-Vasquez, Peter Castro, Charles Benet, Peter Wong, and GovindLakkoju

Contributor: The Oracle Database 12c documentation is dedicated to Mark Townsend, who was aninspiration to all who worked on this release.

This software and related documentation are provided under a license agreement containing restrictions onuse and disclosure and are protected by intellectual property laws. Except as expressly permitted in yourlicense agreement or allowed by law, you may not use, copy, reproduce, translate, broadcast, modify, license,transmit, distribute, exhibit, perform, publish, or display any part, in any form, or by any means. Reverseengineering, disassembly, or decompilation of this software, unless required by law for interoperability, isprohibited.

The information contained herein is subject to change without notice and is not warranted to be error-free. Ifyou find any errors, please report them to us in writing.

If this is software or related documentation that is delivered to the U.S. Government or anyone licensing iton behalf of the U.S. Government, then the following notice is applicable:

U.S. GOVERNMENT END USERS: Oracle programs, including any operating system, integrated software,any programs installed on the hardware, and/or documentation, delivered to U.S. Government end usersare "commercial computer software" pursuant to the applicable Federal Acquisition Regulation andagency-specific supplemental regulations. As such, use, duplication, disclosure, modification, andadaptation of the programs, including any operating system, integrated software, any programs installed onthe hardware, and/or documentation, shall be subject to license terms and license restrictions applicable tothe programs. No other rights are granted to the U.S. Government.

This software or hardware is developed for general use in a variety of information managementapplications. It is not developed or intended for use in any inherently dangerous applications, includingapplications that may create a risk of personal injury. If you use this software or hardware in dangerousapplications, then you shall be responsible to take all appropriate fail-safe, backup, redundancy, and othermeasures to ensure its safe use. Oracle Corporation and its affiliates disclaim any liability for any damagescaused by use of this software or hardware in dangerous applications.

Oracle and Java are registered trademarks of Oracle and/or its affiliates. Other names may be trademarks oftheir respective owners.

Intel and Intel Xeon are trademarks or registered trademarks of Intel Corporation. All SPARC trademarksare used under license and are trademarks or registered trademarks of SPARC International, Inc. AMD,Opteron, the AMD logo, and the AMD Opteron logo are trademarks or registered trademarks of AdvancedMicro Devices. UNIX is a registered trademark of The Open Group.

This software or hardware and documentation may provide access to or information about content,products, and services from third parties. Oracle Corporation and its affiliates are not responsible for andexpressly disclaim all warranties of any kind with respect to third-party content, products, and servicesunless otherwise set forth in an applicable agreement between you and Oracle. Oracle Corporation and itsaffiliates will not be responsible for any loss, costs, or damages incurred due to your access to or use ofthird-party content, products, or services, except as set forth in an applicable agreement between you andOracle.

iii

Contents

Preface ................................................................................................................................................................ ix

Audience...................................................................................................................................................... ixDocumentation Accessibility .................................................................................................................... ixRelated Documents ..................................................................................................................................... xConventions ................................................................................................................................................. x

1 Introduction

Overview .................................................................................................................................................... 1-1Heterogeneous Services Technology.................................................................................................... 1-1Oracle Database Gateways ..................................................................................................................... 1-2

2 Teradata Gateway Features and Restrictions

Using the Pass-Through Feature ........................................................................................................... 2-1Executing Stored Procedures and Functions....................................................................................... 2-2

Return Values and Stored Procedures ............................................................................................ 2-2Result Sets and Stored Procedures .................................................................................................. 2-3

OCI Program Fetching from Result Sets in Sequential Mode .............................................. 2-4PL/SQL Program Fetching from Result Sets in Sequential Mode....................................... 2-5

CHAR Semantics ...................................................................................................................................... 2-6Multi-byte Character Sets Ratio Suppression .................................................................................... 2-6IPv6 Support.............................................................................................................................................. 2-6Gateway Session IDLE Timeout ........................................................................................................... 2-7Database Compatibility Issues for Teradata....................................................................................... 2-7

Schema Considerations ..................................................................................................................... 2-7Naming Rules ..................................................................................................................................... 2-7

Rules for Naming Objects .......................................................................................................... 2-7Case Sensitivity ........................................................................................................................... 2-8

Data Types........................................................................................................................................... 2-8Binary Literal Notation .............................................................................................................. 2-8Data Type Conversion................................................................................................................ 2-9

Queries................................................................................................................................................. 2-9Row Selection .............................................................................................................................. 2-9Empty Bind Variables................................................................................................................. 2-9

Locking ................................................................................................................................................ 2-9Known Restrictions .............................................................................................................................. 2-10

iv

Transactional Integrity .................................................................................................................. 2-10Transaction Capability .................................................................................................................. 2-10COMMIT or ROLLBACK in PL/SQL Cursor Loops Closes Open Cursors .......................... 2-10Pass-Through Feature..................................................................................................................... 2-11Bind Variables for Date Columns ................................................................................................. 2-11SQL Syntax ....................................................................................................................................... 2-11

WHERE CURRENT OF Clause.............................................................................................. 2-11CONNECT BY Clause ............................................................................................................. 2-11ROWID ...................................................................................................................................... 2-11EXPLAIN PLAN Statement.................................................................................................... 2-11Callback Support...................................................................................................................... 2-11

SQL*Plus........................................................................................................................................... 2-12Database Links................................................................................................................................. 2-12CALLBACK links ............................................................................................................................ 2-12

Known Problems ................................................................................................................................... 2-12Teradata LONG VARCHAR Data Type ...................................................................................... 2-13Schema Names and PL/SQL......................................................................................................... 2-13Data Dictionary Views and PL/SQL............................................................................................ 2-13

3 Case Studies

Case Descriptions ..................................................................................................................................... 3-1Installation Media Contents................................................................................................................... 3-1Demonstration Files................................................................................................................................. 3-2Demonstration Requirements................................................................................................................ 3-2Creating Demonstration Tables ............................................................................................................ 3-2

Demonstration Table Definitions..................................................................................................... 3-3Demonstration Table Contents ........................................................................................................ 3-3

Case 1: Simple Queries ........................................................................................................................... 3-4Case 2: A More Complex Query ............................................................................................................ 3-4Case 3: Joining Teradata Tables ........................................................................................................... 3-4Case 4: Write Capabilities....................................................................................................................... 3-5

DELETE Statement............................................................................................................................. 3-5UPDATE Statement ........................................................................................................................... 3-5INSERT Statement.............................................................................................................................. 3-5

Case 5: Data Dictionary Query .............................................................................................................. 3-5Case 6: The Pass-Through Feature ........................................................................................................ 3-5

UPDATE Statement ........................................................................................................................... 3-5SELECT Statement ............................................................................................................................. 3-5

A Data Type Conversion

Data Type Conversion............................................................................................................................ A-1

B Supported SQL Syntax and Functions

Supported SQL Statements ................................................................................................................... B-1DELETE .............................................................................................................................................. B-1INSERT ............................................................................................................................................... B-1

v

SELECT............................................................................................................................................... B-1UPDATE ............................................................................................................................................. B-2

Oracle Functions ...................................................................................................................................... B-2Functions Not Supported by Teradata........................................................................................... B-2Functions Supported by Teradata .................................................................................................. B-2

Arithmetic Operators................................................................................................................. B-2Comparison Operators.............................................................................................................. B-2Group Functions ........................................................................................................................ B-3String Functions ......................................................................................................................... B-3Other Functions.......................................................................................................................... B-3

C Data Dictionary

Data Dictionary Support........................................................................................................................ C-1Teradata System Catalog Tables ..................................................................................................... C-1Accessing the Gateway Data Dictionary ....................................................................................... C-1Direct Queries to Teradata Tables .................................................................................................. C-2Supported Views and Tables........................................................................................................... C-2

Data Dictionary Mapping...................................................................................................................... C-3Default Column Values .................................................................................................................... C-4

Gateway Data Dictionary Descriptions .............................................................................................. C-4

D Initialization Parameters

Initialization Parameter File Syntax .................................................................................................... D-1Oracle Database Gateway for Teradata Initialization Parameters ................................................ D-2Initialization Parameter Description ................................................................................................... D-3

HS_DB_DOMAIN ............................................................................................................................ D-3HS_DB_INTERNAL_NAME .......................................................................................................... D-4HS_DB_NAME ................................................................................................................................. D-4HS_DESCRIBE_CACHE_HWM .................................................................................................... D-4HS_LANGUAGE ............................................................................................................................. D-4

Character Sets ............................................................................................................................. D-5Language..................................................................................................................................... D-5Territory....................................................................................................................................... D-5

HS_LONG_PIECE_TRANSFER_SIZE ......................................................................................... D-5HS_OPEN_CURSORS .................................................................................................................... D-6HS_RPC_FETCH_REBLOCKING ................................................................................................ D-6HS_RPC_FETCH_SIZE ................................................................................................................... D-6HS_TIME_ZONE .............................................................................................................................. D-7HS_TRANSACTION_MODEL ....................................................................................................... D-7IFILE ................................................................................................................................................... D-8HS_FDS_TIMESTAMP_MAPPING................................................................................................ D-8HS_FDS_DATE_MAPPING ............................................................................................................ D-8HS_FDS_CONNECT_INFO ............................................................................................................ D-8HS_FDS_DEFAULT_OWNER ........................................................................................................ D-9HS_FDS_PROC_IS_FUNC............................................................................................................... D-9HS_FDS_RECOVERY_ACCOUNT ................................................................................................ D-9

vi

HS_FDS_RECOVERY_PWD.......................................................................................................... D-10HS_FDS_TRACE_LEVEL............................................................................................................... D-10HS_FDS_TRANSACTION_LOG .................................................................................................. D-10HS_FDS_FETCH_ROWS................................................................................................................ D-11HS_IDLE_TIMEOUT ...................................................................................................................... D-11HS_NLS_LENGTH_SEMANTICS................................................................................................ D-11HS_KEEP_REMOTE_COLUMN_SIZE........................................................................................ D-11HS_FDS_REMOTE_DB_CHARSET ............................................................................................. D-12HS_FDS_SUPPORT_STATISTICS ................................................................................................ D-12HS_FDS_ARRAY_EXEC ................................................................................................................ D-12

vii

viii

List of Tables

A–1 Data Type Mapping and Restrictions .................................................................................... A-1C–1 Oracle Data Dictionary View Names and Teradata Equivalents....................................... C-3C–2 ALL_CATALOG ....................................................................................................................... C-4C–3 ALL_COL_COMMENTS ......................................................................................................... C-4C–4 ALL_CONS_COLUMNS ......................................................................................................... C-4C–5 ALL_CONSTRAINTS............................................................................................................... C-5C–6 ALL_IND_COLUMNS............................................................................................................. C-5C–7 ALL_INDEXES .......................................................................................................................... C-6C–8 ALL_OBJECTS........................................................................................................................... C-7C–9 ALL_TAB_COLUMNS............................................................................................................. C-8C–10 ALL_TAB_COMMENTS.......................................................................................................... C-9C–11 ALL_TABLES............................................................................................................................. C-9C–12 ALL_USERS ............................................................................................................................. C-10C–13 ALL_VIEWS............................................................................................................................. C-10C–14 DBA_CATALOG..................................................................................................................... C-11C–15 DBA_COL_COMMENTS....................................................................................................... C-11C–16 DBA_OBJECTS ........................................................................................................................ C-11C–17 DBA_TAB_COLUMNS .......................................................................................................... C-12C–18 DBA_TAB_COMMENTS....................................................................................................... C-12C–19 DBA_TABLES.......................................................................................................................... C-13C–20 DICT_COLUMNS ................................................................................................................... C-14C–21 DICTIONARY.......................................................................................................................... C-14C–22 DUAL........................................................................................................................................ C-14C–23 USER_CATALOG ................................................................................................................... C-14C–24 USER_COL_COMMENTS..................................................................................................... C-15C–25 USER_CONS_COLUMNS ..................................................................................................... C-15C–26 USER_CONSTRAINTS .......................................................................................................... C-15C–27 USER_IND_COLUMNS......................................................................................................... C-16C–28 USER_INDEXES...................................................................................................................... C-16C–29 USER_OBJECTS ...................................................................................................................... C-17C–30 USER_TAB_COLUMNS ........................................................................................................ C-18C–31 USER_TAB_COMMENTS ..................................................................................................... C-19C–32 USER_TABLES ........................................................................................................................ C-19C–33 USER_USERS........................................................................................................................... C-20C–34 USER_VIEWS .......................................................................................................................... C-21

ix

Preface

This manual describes the Oracle Database Gateway for Teradata, which enablesOracle client applications to access Teradata data through Structured Query Language(SQL). The gateway, with the Oracle database, creates the appearance that all dataresides on a local Oracle database, even though the data can be widely distributed.

This preface covers the following topics:

■ Audience

■ Documentation Accessibility

■ Related Documents

■ Conventions

AudienceThis manual is intended for Oracle database administrators who perform thefollowing tasks:

■ Installing and configuring the Oracle Database Gateway for Teradata

■ Diagnosing gateway errors

■ Using the gateway to access Teradata data

Documentation AccessibilityFor information about Oracle's commitment to accessibility, visit the OracleAccessibility Program website athttp://www.oracle.com/pls/topic/lookup?ctx=acc&id=docacc.

Access to Oracle SupportOracle customers that have purchased support have access to electronic supportthrough My Oracle Support. For information, visithttp://www.oracle.com/pls/topic/lookup?ctx=acc&id=info or visithttp://www.oracle.com/pls/topic/lookup?ctx=acc&id=trs if you are hearingimpaired.

Note: You should understand the fundamentals of OracleDatabase Gateways and the UNIX based platforms before usingthis guide to install or administer the gateway.

x

Related DocumentsFor more information, see these Oracle resources:

■ Oracle Database New Features Guide

■ Oracle Call Interface Programmer's Guide

■ Oracle Database Administrator's Guide

■ Oracle Database Development Guide

■ Oracle Database Concepts

■ Oracle Database Performance Tuning Guide

■ Oracle Database Error Messages

■ Oracle Database Globalization Support Guide

■ Oracle Database Reference

■ Oracle Database SQL Language Reference

■ Oracle Database Net Services Administrator's Guide

■ SQL*Plus User's Guide and Reference

■ Oracle Database Heterogeneous Connectivity User's Guide

■ Oracle Database Security Guide

ConventionsThe following text conventions are used in this document:

Convention Meaning

boldface Boldface type indicates graphical user interface elements associatedwith an action, or terms defined in text or the glossary.

italic Italic type indicates book titles, emphasis, or placeholder variables forwhich you supply particular values.

monospace Monospace type indicates commands within a paragraph, URLs, codein examples, text that appears on the screen, or text that you enter.

1

Introduction 1-1

1 Introduction

This chapter introduces the challenge faced by organizations when running severaldifferent database systems. It briefly covers Heterogeneous Services, the technologythat the Oracle Database Gateway for Teradata is based on.

To get a good understanding of generic gateway technology, Heterogeneous Services,and how Oracle Database Gateways fit in the picture, reading the Oracle DatabaseHeterogeneous Connectivity User's Guide first is highly recommended.

This chapter contains the following sections:

■ Overview

■ Heterogeneous Services Technology

■ Oracle Database Gateways

OverviewHeterogeneous data access is a problem that affects a lot of companies. A lot ofcompanies run several different database systems. Each of these systems stores dataand has a set of applications that run against it. Consolidation of this data in onedatabase system is often hard - in large part because many of the applications that runagainst one database may not have an equivalent that runs against another. Until suchtime as migration to one consolidated database system is made feasible, it is necessaryfor the various heterogeneous database systems to interoperate.

Oracle Database Gateways provide the ability to transparently access data residing ina non-Oracle system from an Oracle environment. This transparency eliminates theneed for application developers to customize their applications to access data fromdifferent non-Oracle systems, thus decreasing development efforts and increasing themobility of the application. Applications can be developed using a consistent Oracleinterface for both Oracle and Teradata.

Gateway technology is composed of two parts: a component that has the generictechnology to connect to a non-Oracle system, which is common to all the non-Oraclesystems, called Heterogeneous Services, and a component that is specific to thenon-Oracle system that the gateway connects to. Heterogeneous Services, inconjunction with the Oracle Database Gateway agent, enables transparent access tonon-Oracle systems from an Oracle environment.

Heterogeneous Services TechnologyHeterogeneous Services provides the generic technology for connecting to non-Oraclesystems. As an integrated component of the database, Heterogeneous Services can

Oracle Database Gateways

1-2 Oracle Database Gateway for Teradata User's Guide

exploit features of the database, such as the powerful SQL parsing and distributedoptimization capabilities.

Heterogeneous Services extend the Oracle SQL engine to recognize the SQL andprocedural capabilities of the remote non-Oracle system and the mappings required toobtain necessary data dictionary information. Heterogeneous Services provides twotypes of translations: the ability to translate Oracle SQL into the proper dialect of thenon-Oracle system as well as data dictionary translations that displays the metadata ofthe non-Oracle system in the local format. For situations where no translations areavailable, native SQL can be issued to the non-Oracle system using the pass-throughfeature of Heterogeneous Services.

Heterogeneous Services also maintains the transaction coordination between Oracleand the remote non-Oracle system, such as providing the two-phase commit protocolto ensure distributed transaction integrity, even for non-Oracle systems that do notnatively support two-phase commit.

Oracle Database GatewaysThe capabilities, SQL mappings, data type conversions, and interface to the remotenon-Oracle system are contained in the gateway. The gateway interacts withHeterogeneous Services to provide the transparent connectivity between Oracle andnon-Oracle systems.

The gateway must be installed on a machine running either the Teradata database orthe Teradata client. This machine can be the same machine as the Oracle database oron the same machine as the Teradata database or on a third machine as a standalone.Each configuration has its advantages and disadvantages. The issues to consider whendetermining where to install the gateway are network traffic, operating systemplatform availability, hardware resources and storage.

See Also: Oracle Database Heterogeneous Connectivity User's Guidefor more information about Heterogeneous Services.

2

Teradata Gateway Features and Restrictions 2-1

2 Teradata Gateway Features and Restrictions

After the gateway is installed and configured, you can use the gateway to accessTeradata data, pass Teradata commands from applications to the Teradata database,perform distributed queries, and copy data.

This chapter contains the following sections:

■ Using the Pass-Through Feature

■ Executing Stored Procedures and Functions

■ CHAR Semantics

■ Multi-byte Character Sets Ratio Suppression

■ IPv6 Support

■ Gateway Session IDLE Timeout

■ Database Compatibility Issues for Teradata

■ Known Restrictions

■ Known Problems

Using the Pass-Through FeatureThe gateway can pass Teradata commands or statements from the application directlyto the Teradata database using the DBMS_HS_PASSTHROUGH package.

Use the DBMS_HS_PASSTHROUGH package in a PL/SQL block to specify the statement tobe passed to the Teradata database, as follows:

DECLAREnum_rows INTEGER;

BEGINnum_rows := DBMS_HS_PASSTHROUGH.EXECUTE_IMMEDIATE@TERA('command');

END;/

Where command cannot be one of the following:

■ BEGIN TRANSACTION

■ BT

■ COMMIT

■ END TRANSACTION

■ ET

Executing Stored Procedures and Functions

2-2 Oracle Database Gateway for Teradata User's Guide

■ ROLLBACK

The DBMS_HS_PASSTHROUGH package supports passing bind values and executingSELECT statements.

Executing Stored Procedures and FunctionsUsing the procedural feature, the gateway can execute stored procedures that aredefined in the Teradata database. It is not necessary to relink the gateway or define theprocedure to the gateway, but the procedure's access privileges must permit access bythe gateway.

Standard PL/SQL statements are used to execute a stored procedure.

The gateway supports stored procedures in three mutually exclusive modes:

■ Normal mode: Have access to IN/OUT arguments only

■ Return value mode: Have a return value for all stored procedures

■ Resultset mode: Out values are available as last result set

Return Values and Stored ProceduresBy default, all stored procedures and functions do not return a return value to the user.To enable return values, set the HS_FDS_PROC_IS_FUNC parameter in the initializationparameter file.

In the following example, the employee name JOHN SMYTHE is passed to the Teradatastored procedure REVISE_SALARY. The stored procedure retrieves the salary value fromthe Teradata database to calculate a new yearly salary for JOHN SMYTHE. The revisedsalary returned in RESULT is used to update EMP in a table of an Oracle database:

DECLAREINPUT VARCHAR2(15);RESULT NUMBER(8,2);

BEGININPUT := 'JOHN SMYTHE';RESULT := REVISE_SALARY@TERA(INPUT);UPDATE EMP SET SAL = RESULT WHERE ENAME =: INPUT;

END;

See Also: Oracle Database PL/SQL Packages and Types Reference andChapter 3, Features of Oracle Database Gateways, of OracleDatabase Heterogeneous Connectivity User's Guide for moreinformation about the DBMS_HS_PASSTHROUGH package.

See Also: Oracle Database Heterogeneous Connectivity User's Guidefor more information about executing stored procedures.

See Also: Appendix D, "Initialization Parameters" for informationabout both editing the initialization parameter file and the HS_FDS_PROC_IS_FUNC parameter.

Note: If you set the HS_FDS_PROC_IS_FUNC gateway initializationparameter, you must change the syntax of the procedure executestatement for all existing stored procedures.

Executing Stored Procedures and Functions

Teradata Gateway Features and Restrictions 2-3

/

The procedural feature automatically converts non-Oracle data types to and fromPL/SQL data types.

Result Sets and Stored ProceduresThe Oracle Database Gateway for Teradata provides support for stored procedureswhich return result sets.

By default, all stored procedures and functions do not return a result set to the user. Toenable result sets, set the HS_FDS_RESULTSET_SUPPORT parameter in the initializationparameter file.

When accessing stored procedures with result sets through the Oracle DatabaseGateway for Teradata, you will be in the sequential mode of Heterogeneous Services.

The Oracle Database Gateway for Teradata returns the following information toHeterogeneous Services during procedure description:

■ All the input arguments of the remote stored procedure

■ None of the output arguments

■ One out argument of type ref cursor (corresponding to the first result set returnedby the stored procedure)

Client programs have to use the virtual package function dbms_hs_result_set.get_next_result_set to get the ref cursor for subsequent result sets. The last result setreturned is the out argument from the procedure.

The limitations of accessing result sets are the following:

■ Result sets returned by a remote stored procedure have to be retrieved in the orderin which they were placed on the wire

■ On execution of a stored procedure, all result sets returned by a previouslyexecuted stored procedure will be closed (regardless of whether the data has beencompletely

In the following example, the Teradata stored procedure is executed to fetch thecontents of the emp and dept tables from Teradata:

CREATE PROCEDURE refcurproc (@arg1 varchar(255), @arg2 varchar(255) output)ASSECLECT @arg2 = @arg1SELECT * FROM EMPSELECT * FROM DEPTGO

See Also: Appendix D, "Initialization Parameters" for informationabout both editing the initialization parameter file and the HS_FDS_RESULTSET_SUPPORT parameter. For further information aboutOracle support for result sets in non-Oracle databases see OracleDatabase Heterogeneous Connectivity User's Guide.

Note: If you set the HS_FDS_RESULTSET_SUPPORT gatewayinitialization parameter, you must change the syntax of theprocedure execute statement for all existing stored procedures orerrors will occur.

Executing Stored Procedures and Functions

2-4 Oracle Database Gateway for Teradata User's Guide

This stored procedure assigns the input parameter arg1 to the output parameter arg2,opens the query SELECT * FROM EMP in ref cursor rc1, and opens the query SELECT *FROM DEPT in ref cursor rc2.

OCI Program Fetching from Result Sets in Sequential ModeThe following example shows OCI program fetching from result sets in sequentialmode:

OCIEnv *ENVH;OCISvcCtx *SVCH;OCIStmt *STMH;OCIError *ERRH;OCIBind *BNDH[3];OraText arg1[20];OraText arg2[255];OCIResult *rset;OCIStmt *rstmt;ub2 rcode[3];ub2 rlens[3];sb2 inds[3];OraText *stmt = (OraText *) "begin refcurproc@TERA(:1,:2,:3); end;";OraText *n_rs_stm = (OraText *)

"begin :ret := DBMS_HS_RESULT_SET.GET_NEXT_RESULT_SET@TERA; end;";

/* Prepare procedure call statement */

/* Handle Initialization code skipped */OCIStmtPrepare(STMH, ERRH, stmt, strlen(stmt), OCI_NTV_SYNTAX, OCI_DEFAULT);

/* Bind procedure arguments */inds[0] = 0;strcpy((char *) arg1, "Hello World");rlens[0] = strlen(arg1);OCIBindByPos(STMH, &BNDH[0], ERRH, 1, (dvoid *) arg1, 20, SQLT_CHR,

(dvoid *) &(inds[0]), &(rlens[0]), &(rcode[0]), 0, (ub4 *) 0,OCI_DEFAULT);

inds[1] = -1;OCIBindByPos(STMH, &BNDH[1], ERRH, 1, (dvoid *) arg2, 20, SQLT_CHR,

(dvoid *) &(inds[1]), &(rlens[1]), &(rcode[1]), 0, (ub4 *) 0,OCI_DEFAULT);

inds[2] = 0;rlens[2] = 0;OCIDescriptorAlloc(ENVH, (dvoid **) &rset, OCI_DTYPE_RSET, 0, (dvoid **) 0);OCIBindByPos(STMH, &BNDH[2], ERRH, 2, (dvoid *) rset, 0, SQLT_RSET,

(dvoid *) &(inds[2]), &(rlens[2]), &(rcode[2]),0, (ub4 *) 0, OCI_DEFAULT);

/* Execute procedure */OCIStmtExecute(SVCH, STMH, ERRH, 1, 0, (CONST OCISnapshot *) 0,

(OCISnapshot *) 0, OCI_DEFAULT);

/* Convert result set to statement handle */

Note: Chained mode must be set before creating the storedprocedure. Issue the following command in Teradata: set chainedon

Executing Stored Procedures and Functions

Teradata Gateway Features and Restrictions 2-5

OCIResultSetToStmt(rset, ERRH);rstmt = (OCIStmt *) rset;

/* After this the user can fetch from rstmt *//* Issue get_next_result_set call to get handle to next_result set *//* Prepare Get next result set procedure call */

OCIStmtPrepare(STMH, ERRH, n_rs_stm, strlen(n_rs_stm), OCI_NTV_SYNTAX,OCI_DEFAULT);

/* Bind return value */OCIBindByPos(STMH, &BNDH[1], ERRH, 1, (dvoid *) rset, 0, SQLT_RSET,

(dvoid *) &(inds[1]), &(rlens[1]), &(rcode[1]),0, (ub4 *) 0, OCI_DEFAULT);

/* Execute statement to get next result set*/OCIStmtExecute(SVCH, STMH, ERRH, 1, 0, (CONST OCISnapshot *) 0,

(OCISnapshot *) 0, OCI_DEFAULT);

/* Convert next result set to statement handle */OCIResultSetToStmt(rset, ERRH);rstmt = (OCIStmt *) rset;

/* Now rstmt will point to the second result set returned by theremote stored procedure */

/* Repeat execution of get_next_result_set to get the output arguments */

PL/SQL Program Fetching from Result Sets in Sequential ModeAssume that the table loc_emp is a local table exactly like the Teradata emp table. Thesame assumption applies for loc_dept. outargs is a table with columns correspondingto the out arguments of the Teradata stored procedure.

create or replace package rcpackage istype RCTYPE is ref cursor;

end rcpackage;/declare

rc1 rcpackage.rctype;rec1 loc_emp%rowtype;rc2 rcpackage.rctype;rec2 loc_dept%rowtype;rc3 rcpackage.rctype;rec3 outargs%rowtype;out_arg varchar2(255);

begin

-- Execute procedureout_arg := null;refcurproc@TERA('Hello World', out_arg, rc1);

-- Fetch 20 rows from the remote emp table and insert them into loc_empfor i in 1 .. 20 loop

fetch rc1 into rec1;insert into loc_emp (rec1.empno, rec1.ename, rec1.job,rec1.mgr, rec1.hiredate, rec1.sal, rec1.comm, rec1.deptno);

end loop;

CHAR Semantics

2-6 Oracle Database Gateway for Teradata User's Guide

-- Close ref cursorclose rc1;

-- Get the next result set returned by the stored procedurerc2 := dbms_hs_result_set.get_next_result_set@TERA;

-- Fetch 5 rows from the remote dept table and insert them into loc_deptfor i in 1 .. 5 loop

fetch rc2 into rec2;insert into loc_dept values (rec2.deptno, rec2.dname, rec2.loc);

end loop;

--Close ref cursorclose rc2;

-- Get the output arguments from the remote stored procedure-- Since we are in sequential mode, they will be returned in the-- form of a result setrc3 := dbms_hs_result_set.get_next_result_set@TERA;

-- Fetch them and insert them into the outarguments tablefetch rc3 into rec3;insert into outargs (rec3.outarg, rec3.retval);

-- Close ref cursorclose rc3;

end;/

CHAR SemanticsThis feature allows the gateway to optionally run in CHAR Semantics mode. Ratherthan always describing Teradata CHAR columns as CHAR(n BYTE), this feature describesthem as CHAR(n CHAR) and VARCHAR(n CHAR). The concept is similar to Oracledatabase CHAR Semantics. You need to specify HS_NLS_LENGTH_SEMANTICS=CHAR toactivate this option. Refer to Appendix D for more detail.

Multi-byte Character Sets Ratio SuppressionThis feature optionally suppresses the ratio expansion from Teradata database toOracle databases involving a multi-byte character set (for example, from US7ASCII toAL32UTF8, or from KO16MSWIN949 to KO16KSC5601). By default, Oracle gatewaysassume the worst ratio to prevent data being truncated or allocation of buffer withinsufficient size. However, if you have specific knowledge of your Teradata databaseand do not want the expansion to occur, you can specify HS_KEEP_REMOTE_COLUMN_SIZE parameter to suppress the expansion. Refer to Appendix D for more detail.

IPv6 SupportBesides full IPv6 support between Oracle databases and the gateway, IPv6 is alsosupported between this gateway and Teradata. Refer to HS_FDS_CONNECT_INFOparameter in Appendix D for more detail.

Database Compatibility Issues for Teradata

Teradata Gateway Features and Restrictions 2-7

Gateway Session IDLE TimeoutYou can optionally choose to terminate long idle gateway sessions automatically withthe gateway parameter HS_IDLE_TIMEOUT. Specifically, when a gateway session is idlefor more than the specified time limit, the gateway session is terminated with anypending changes rolled back.

Database Compatibility Issues for TeradataTeradata and Oracle databases function differently in some areas, causingcompatibility problems. The following compatibility issues are described in thissection:

■ Schema Considerations

■ Naming Rules

■ Data Types

■ Queries

■ Locking

Schema ConsiderationsThe Oracle concept of a schema does not exist in Teradata. A schema name included ina query is recognized by Teradata as a database name. In the Oracle database, theschema of an object is identical to the owner of that object. However, when oneretrieves or references an OWNER field in a Data Dictionary view such as ALL_TABLES,the OWNER field really is referencing a Teradata database name.

When querying data dictionary tables, the following results are returned:

■ ALL_* data dictionary tables, data for every Teradata database is returned. TheTeradata database name is returned in the OWNER, INDEX_OWNER, or TABLE_OWNERcolumn depending on the data dictionary table being referenced.

■ ALL_USERS data dictionary table, each Teradata database name is returned in theUSERNAME column.

■ USER_* data dictionary tables, data for the default Teradata database is returnedfor the OWNER or TABLE_OWNER column depending on the data dictionary table beingreferenced. If a default Teradata database is not defined, the DBC Teradata systemdatabase is used.

Naming RulesNaming rule issues include the following:

■ Rules for Naming Objects

■ Case Sensitivity

Rules for Naming ObjectsOracle and Teradata use different database object naming rules. For example, themaximum number of characters allowed for each object name can be different. Also,the use of single and double quotation marks, case sensitivity, and the use ofalphanumeric characters can all be different.

See Also: Oracle Database Reference and Teradata documentation.

Database Compatibility Issues for Teradata

2-8 Oracle Database Gateway for Teradata User's Guide

Case SensitivityThe Oracle database defaults to uppercase unless you surround identifiers withdouble quote characters. For example, to refer to the Teradata table called emp, enterthe name with double quote characters, as follows:

SQL> SELECT * FROM "emp"@TERA;

However, to refer to the Teradata table called emp in the Teradata database named Scottfrom an Oracle application, enter the following:

SQL> SELECT * FROM "Scott"."emp"@TERA;

If the Teradata table called emp in the Teradata database named SCOTT, a nameconsisting entirely of uppercase letters, you can enter the owner name without doublequote characters, as follows:

SQL> SELECT * FROM SCOTT."emp"@TERA;

or

SQL> SELECT * FROM scott."emp"@TERA;

Oracle recommends that you surround all Teradata object names with double quotecharacters and use the exact letter case for the object names as they appear in theTeradata data dictionary. This convention is not required when referring to thesupported Oracle data dictionary tables or views listed in Appendix C, "DataDictionary".

If existing applications cannot be changed according to these conventions, create viewsin Oracle to associate Teradata names to the correct letter case. For example, to refer tothe Teradata table emp from an existing Oracle application by using only uppercasenames, define the following view:

SQL> CREATE VIEW EMP (EMPNO, ENAME, SAL, HIREDATE)AS SELECT "empno", "ename", "sal", "hiredate"FROM "emp"@TERA;

With this view, the application can issue statements such as the following:

SQL> SELECT EMPNO, ENAME FROM EMP;

Using views is a workaround solution that duplicates data dictionary informationoriginating in the Teradata data dictionary. You must be prepared to update the Oracleview definitions whenever the data definitions for the corresponding tables arechanged in the Teradata database.

Data TypesData type issues include the following:

■ Binary Literal Notation

■ Data Type Conversion

Binary Literal NotationOracle SQL uses hexadecimal digits surrounded by single quotes to express literalvalues being compared or inserted into columns defined as data type RAW.

This notation is not converted to syntax compatible with the Teradata VARBINARY andBINARY data types (a ff surrounded by single quotes followed by hexadecimal digits).

Database Compatibility Issues for Teradata

Teradata Gateway Features and Restrictions 2-9

For example, the following statement is not supported:

SQL> INSERT INTO BINARY_TAB@TERA VALUES (’ff’xb)

where BINARY_TAB contains a column of data type VARBINARY or BINARY. Use bindvariables when inserting into or updating VARBINARY and BINARY data types.

Data Type ConversionTeradata does not support implicit date conversions. Such conversions must beexplicit.

For example, the gateway issues an error for the following SELECT statement:

SELECT DATE_COL FROM TEST@TERA WHERE DATE_COL = "1-JAN-2001";

To avoid problems with implicit conversions, add explicit conversions, as in thefollowing:

SELECT DATE_COL FROM TEST@TERA WHERE DATE_COL = TO_DATE("1-JAN-2001")

QueriesQuery issues include the following:

■ Row Selection

■ Empty Bind Variables

Row SelectionTeradata evaluates a query condition for all selected rows before returning any of therows. If there is an error in the evaluation process for one or more rows, no rows arereturned even though the remaining rows satisfy the condition.

Oracle evaluates the query condition row-by-row and returns a row when theevaluation is successful. Rows are returned until a row fails the evaluation.

Empty Bind VariablesFor VARCHAR bind variables, the gateway passes empty bind variables to the Teradatadatabase as a NULL value.

LockingThe locking model for an Teradata database differs significantly from the Oraclemodel. The gateway depends on the underlying Teradata behavior, so the followingpossible scenarios can affect Oracle applications that access Teradata through thegateway:

■ Read access might block write access.

■ Write access might block read access.

■ Statement-level read consistency is not guaranteed.

See Also: Appendix A, "Data Type Conversion" for moreinformation about restrictions on data types.

See Also: Teradata documentation for information about theTeradata locking model.

Known Restrictions

2-10 Oracle Database Gateway for Teradata User's Guide

Known RestrictionsIf you encounter incompatibility problems not listed in this section or in "KnownProblems" on page 2-12, contact Oracle Support Services. The following sectiondescribes the known restrictions and includes suggestions for dealing with them whenpossible:

■ Transactional Integrity

■ Transaction Capability

■ COMMIT or ROLLBACK in PL/SQL Cursor Loops Closes Open Cursors

■ Pass-Through Feature

■ Bind Variables for Date Columns

■ SQL Syntax

■ SQL*Plus

■ Database Links

Transactional IntegrityThe gateway cannot guarantee transactional integrity in the following cases:

■ When a statement that is processed by the gateway causes an implicit commit inthe target database

■ When the target database is configured to work in autocommit mode

Transaction CapabilityThe gateway does not support savepoints. If a distributed update transaction is underway involving the gateway and a user attempts to create a savepoint, the followingerror occurs:

ORA-02070: database dblink does not support savepoint in this context

By default, the gateway is configured as COMMIT_CONFIRM and it is always the commitpoint site when the Teradata database is updated by the transaction.

COMMIT or ROLLBACK in PL/SQL Cursor Loops Closes Open CursorsAny COMMIT or ROLLBACK issued in a PL/SQL cursor loop closes all open cursors,which can result in the following error:

ORA-1002: fetch out of sequence

To prevent this error, move the COMMIT or ROLLBACK statement outside the cursor loop.

Note: Oracle strongly recommends the following:

■ If you know that executing a particular statement causes animplicit commit in the target database, then ensure that thisstatement is executed in its own transaction.

■ Do not configure the target database to work in autocommitmode.

Known Restrictions

Teradata Gateway Features and Restrictions 2-11

Pass-Through FeatureOracle recommends that you place a DDL statement in its own transaction whenexecuting such a statement with the pass-through feature. An explicit COMMIT must beissued after the DDL statement.

If the SQL statements being passed through the gateway result in an implicit commitat the Teradata database, the Oracle transaction manager is unaware of the commitand an Oracle ROLLBACK command cannot be used to roll back the transaction.

Bind Variables for Date ColumnsYou cannot compare columns of data type TIME or TIMESTAMP to a bind variable.

The following SQL statement causes an error message:

SQL> select time_column from time_table@TERA where time_column = :a;

The following error is issued:

Invalid operation on an ANSI Datetime or Interval value.

SQL SyntaxThis section lists restrictions on the following SQL syntax:

■ WHERE CURRENT OF Clause

■ CONNECT BY Clause

■ ROWID

■ EXPLAIN PLAN Statement

■ Callback Support

WHERE CURRENT OF ClauseUPDATE and DELETE statements with the WHERE CURRENT OF clause are not supported bythe gateway because they rely on the Oracle ROWID implementation. To update ordelete a specific row through the gateway, a condition style WHERE clause must be used.

CONNECT BY ClauseThe gateway does not support the CONNECT BY clause in a SELECT statement.

ROWIDThe Oracle ROWID implementation is not supported.

EXPLAIN PLAN StatementThe EXPLAIN PLAN statement is not supported.

Callback SupportSQL statements that require the gateway to callback to Oracle database are notsupported.

The following categories of SQL statements will result in a callback:

See Also: Appendix B, "Supported SQL Syntax and Functions"for more information about restrictions on SQL syntax.

Known Problems

2-12 Oracle Database Gateway for Teradata User's Guide

■ Any DML with a sub-select, which refers to a table in Oracle database. Forexample:

INSERT INTO emp@TERA SELECT * FROM oracle_emp;

■ Any DELETE, INSERT, UPDATE or "SELECT... FOR UPDATE..." SQL statementcontaining SQL functions or statements that needs to be executed at theoriginating Oracle database.

These SQL functions include USER, USERENV, and SYSDATE; and invovle theselection of data from the originating Oracle database. For example:

DELETE FROM emp@TERA WHERE hiredate > SYSDATE;

SELECT ename FROM tkhoemp@TERAWHERE hiredate IN (SELECT hiredate FROM oracle_emp)FOR UPDATE OF empno;

■ Any SQL statement that involves a table in Oracle database, and a LONG or LOBcolumn in a remote table. For example:

SELECT a.long1, b.empno FROM scott.table@TERA a, emp bWHERE a.id=b.empno;

SELECT a.long1, b.dummy FROM table_non@TERA a, dual b;

where a.long1 is a LONG column.

SQL*PlusYou need to use double quotes to wrap around lowercase table names.

For example:

copy from tkhouser/tkhouser@inst1 insert loc_tkhodept using select * from"tkhodept"@TERA;

Database LinksThe gateway is not a shared server process and cannot support shared database links.Each gateway session spawns a separate gateway process and connections cannot beshared.

CALLBACK linksOracle Database Gateway for Teradata does not support CALLBACK links. Attempting touse a CALLBACK link with the gateway will return the following error message:

ORA-02025: All tables in the SQL statement must be at the remote database

Known ProblemsThis section describes known problems and includes suggestions for correcting themwhen possible. If you have any questions or concerns about the problems, contactOracle Support Services. A current list of problems is available online. Contact yourlocal Oracle office for information about accessing the list.

The following known problems are described in this section:

■ Teradata LONG VARCHAR Data Type

Known Problems

Teradata Gateway Features and Restrictions 2-13

■ Schema Names and PL/SQL

■ Data Dictionary Views and PL/SQL

Teradata LONG VARCHAR Data TypeThe following restrictions apply when using LONG VARCHAR data types:

■ An unsupported SQL function cannot be used in a SQL statement that accesses acolumn defined as Teradata data type LONG VARCHAR.

■ You cannot use SQL*Plus to select data from a column defined as Teradata datatype LONG VARCHAR when the data is greater than 80 characters in length. Oraclerecommends using Pro*C or Oracle Call Interface to access such data in a Teradatadatabase.

■ LONG VARCHAR data types must be NULLABLE for INSERT or UPDATE to work.

■ A table including a LONG VARCHAR column must have a unique index defined onthe table or the table must have a separate column that serves as a primary key.

■ LONG VARCHAR data cannot be read through pass-through queries.

The gateway does not support the PL/SQL function COLUMN_VALUE_LONG of the DBMS_SQL package.

Schema Names and PL/SQLIf you do not prefix a Teradata database object with its schema name in a SQLstatement within a PL/SQL block, the following error message occurs:

ORA-6550 PLS-201 Identifier table_name must be declared.

Change the SQL statement to include the schema name of the object.

Data Dictionary Views and PL/SQLYou cannot refer to data dictionary views in SQL statements that are inside a PL/SQLblock.

See Also: Appendix B, "Supported SQL Syntax and Functions"for more information about restrictions on SQL syntax.

Known Problems

2-14 Oracle Database Gateway for Teradata User's Guide

3

Case Studies 3-1

3 Case Studies

The following case studies for Teradata demonstrate some of the features of the OracleDatabase Gateway. You can verify that the gateway is installed and operating correctlyby using the demonstration files included on the distribution media.

The demonstration files are automatically copied to disk when the gateway isinstalled.

This chapter contains the following sections:

■ Case Descriptions

■ Installation Media Contents

■ Demonstration Files

■ Demonstration Requirements

■ Creating Demonstration Tables

■ Case 1: Simple Queries

■ Case 2: A More Complex Query

■ Case 3: Joining Teradata Tables

■ Case 4: Write Capabilities

■ Case 5: Data Dictionary Query

■ Case 6: The Pass-Through Feature

Case DescriptionsThe cases illustrate:

■ A simple query (Case 1)

■ A more complex query (Case 2)

■ Joining Teradata tables (Case 3)

■ Write capabilities (Case 4)

■ A data dictionary query (Case 5)

■ The pass-through feature (Case 6)

Installation Media ContentsThe distribution media contains the following:

Demonstration Files

3-2 Oracle Database Gateway for Teradata User's Guide

■ Demonstration files.

■ One SQL script file that creates the demonstration tables in the Teradata database.

■ One SQL script file that drops the demonstration tables from the Teradatadatabase.

Demonstration FilesAfter a successful gateway installation, use the demonstration files stored in thedirectory $ORACLE_HOME/dg4tera/demo where $ORACLE_HOME is the directory underwhich the gateway is installed. The directory contains the following demonstrationfiles:

■ bldtera.sql

■ case1.sql

■ case2.sql

■ case3.sql

■ case4a.sql

■ case4b.sql

■ case4c.sql

■ case5.sql

■ case6a.sql

■ case6b.sql

■ droptera.sql

Demonstration RequirementsThe case studies assume these requirements have been met:

■ The gateway demonstration tables are installed in the Teradata database.

■ The Oracle database has an account named SCOTT with a password of TIGER.

■ The Oracle database has a database link called GTWLINK (set up as public or privateto the user SCOTT) that connects the gateway to a Teradata database as SCOTT withpassword TIGER2.

For example, you can create the database link as follows:

SQL> CREATE DATABASE LINK GTWLINK CONNECT TO SCOTT2 IDENTIFIED BY TIGER2 USING ’GTWSID’;

■ Oracle Net Services is configured correctly and running.

Creating Demonstration TablesThe case studies are based on the GTW_EMP, GTW_DEPT, and GTW_SALGRADE tables. If thedemonstration tables have not been created in the Teradata database, use thebldtera.sql script to create them.

The script creates the demonstration tables in the Teradata database accordingly:

CREATE TABLE GTW_EMP (EMPNO SMALLINT NOT NULL

Creating Demonstration Tables

Case Studies 3-3

ENAME VARCHAR(10),JOB VARCHAR(9),MGR SMALLINT,HIREDATE DATETIME,SAL NUMERIC(7,2),COMM NUMERIC(7,2),DEPTNO SMALLINT)CREATE TABLE GTW_DEPT (DEPTNO SMALLINT NOT NULL,DNAME VARCHAR(14),LOC VARCHAR(13))CREATE TABLE GTW_SALGRADE (GRADE REAL,LOSAL NUMERIC(9,4),HISAL NUMERIC(9,4))

Demonstration Table DefinitionsThe table definitions are listed here using information retrieved by the SQL*PLUSDESCRIBE command:

GTW_EMP

Name Null? Type------------------------------- -------- ----EMPNO NOT NULL NUMBER(5)ENAME VARCHAR2(10)JOB VARCHAR2(9)MGR NUMBER(5)HIREDATE DATESAL NUMBER(7,2)COMM NUMBER(7,2)DEPTNO NUMBER(5)

GTW_DEPT

Name Null? Type------------------------------- -------- ----DEPTNO NOT NULL NUMBER(5)DNAME VARCHAR2(14)LOC VARCHAR2(13)

GTW_SALGRADE

Name Null? Type------------------------------- -------- ----GRADE FLOAT(53)LOSAL NUMBER(9,4)HISAL NUMBER(9,4)

Demonstration Table ContentsThe contents of the Teradata tables are:

GTW_EMP

EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO----- ----- --- --- -------- --- ---- ------7369 SMITH CLERK 7902 17-DEC-80 800 207499 ALLEN SALESMAN 7698 20-FEB-81 1600 300 30

Case 1: Simple Queries

3-4 Oracle Database Gateway for Teradata User's Guide

7521 WARD SALESMAN 7698 22-FEB-81 1250 500 307566 JONES MANAGER 7839 02-APR-81 2975 207654 MARTIN SALESMAN 7698 28-SEP-81 1250 1400 307698 BLAKE MANAGER 7839 01-MAY-81 2850 307782 CLARK MANAGER 7839 09-JUN-81 2450 107788 SCOTT ANALYST 7566 09-DEC-82 3000 207839 KING PRESIDENT 17-NOV-81 5000 107844 TURNER SALESMAN 7698 08-SEP-81 1500 0 307876 ADAMS CLERK 7788 12-JAN-83 1100 207900 JAMES CLERK 7698 03-DEC-81 950 307902 FORD ANALYST 7566 03-DEC-81 3000 207934 MILLER CLERK 7782 23-JAN-82 1300 10

GTW_DEPT

DEPTNO DNAME LOC----- -------------- --------

10 ACCOUNTING NEW YORK20 RESEARCH DALLAS30 SALES CHICAGO40 OPERATIONS BOSTON

GTW_SALGRADE

GRADE LOSAL HISAL------ ------ -----

1 700 12002 1201 14003 1401 20004 2001 30005 3001 9999

Case 1: Simple QueriesCase 1 demonstrates the following:

■ A simple query.

■ A simple query retrieving full date information.

The first query retrieves all the data from GTW_DEPT and confirms that the gateway isworking correctly.

Case 2: A More Complex QueryCase 2 demonstrates the following:

■ The functions SUM(expression) and NVL(expr1, expr2) in the SELECT list.

■ The GROUP BY and HAVING clauses.

This query retrieves the departments from GTW_EMP whose total monthly expenses arehigher than $10,000.

Case 3: Joining Teradata TablesCase 3 demonstrates the following:

■ Joins between Teradata tables.

■ Subselects.

Case 6: The Pass-Through Feature

Case Studies 3-5

The query retrieves information from three Teradata tables and relates the employeesto their department name and salary grade, but only for those employees earningmore than the average salary.

Case 4: Write CapabilitiesCase 4 is split into three cases and demonstrates the following:

■ DELETE Statement

■ UPDATE Statement

■ INSERT Statement

DELETE StatementCase 4a demonstrates bind values and subselect. All employees in department 20 andone employee, WARD, in department 30 are deleted.

UPDATE StatementCase 4b provides an example of a simple UPDATE statement. In this example,employees are given a $100 a month salary increase.

INSERT StatementCase 4c is an example of a simple insert statement that does not provide informationfor all columns.

Case 5: Data Dictionary QueryCase 5 demonstrates data dictionary mapping. It retrieves all the tables and views thatexist in the Teradata database that begin with "GTW".

Case 6: The Pass-Through FeatureCase 6 demonstrates the gateway pass-through feature that allows an application tosend commands or statements to Teradata.

This case demonstrates:

■ A pass-through UPDATE statement using bind variables.

■ A pass-through SELECT statement.

UPDATE StatementCase 6a provides an example of a pass-through UPDATE statement with bind variables.In this example, the salary for EMPNO 7934 is set to 4000.

SELECT StatementCase 6b provides an example of a pass-through SELECT statement. The data that isreturned from the SELECT statement is inserted into a local table at the Oracle database.

Case 6: The Pass-Through Feature

3-6 Oracle Database Gateway for Teradata User's Guide

A

Data Type Conversion A-1

A Data Type Conversion

This appendix contains the following section:

■ Data Type Conversion

Data Type ConversionThe gateway converts Teradata data types to Oracle data types as follows:

Table A–1 Data Type Mapping and Restrictions

Teradata Oracle CriteriaIf Oracle uses large varchar(32k)

BLOB LONG RAW

BYTE RAW -

BYTEINT NUMBER(3) BYTEINT range is -128 to +127

CHAR CHAR -

CHAR CHARACTERSET UNICODE

CHAR -

CLOB LONG

DATE CHAR(10) -

DECIMAL NUMBER(p[,s]) -

FLOAT FLOAT(24) with precision <= single precisionfloat

FLOAT FLOAT(53) with precision > single precisionfloat

INTEGER NUMBER(10) NUMBER range is -2,147,483,648to 2,147,483,647

INTERVAL CHAR -

LONG VARCHARCHARACTER SETUNICODE

LONG if Oracle DB Character Set =Unicode. Otherwise, it is notsupported.

LONG VARCHAR LONG if Oracle DB Character Set =Unicode. Otherwise, it is notsupported

SMALLINT NUMBER(5) NUMBER range is -32768 to 32767

TIME CHAR(15) -

TIMESTAMP DATE -

Data Type Conversion

A-2 Oracle Database Gateway for Teradata User's Guide

VARBYTE RAW 1 < = N < = 2000 1 <= N <= 32767

VARBYTE LONG RAW 2000 < N N < 32767

VARCHAR VARCHAR2

LONG

N < = 4000

4000 < N

N <= 32767

32767 < N

VARCHAR()CHARACTER SETUNICO

NVARCHAR2 N < = 2000

4000 < N

Table A–1 (Cont.) Data Type Mapping and Restrictions

Teradata Oracle CriteriaIf Oracle uses large varchar(32k)

B

Supported SQL Syntax and Functions B-1

B Supported SQL Syntax and Functions

This appendix contains the following sections:

■ Supported SQL Statements

■ Oracle Functions

Supported SQL StatementsWith a few exceptions, the gateway provides full support for Oracle DELETE, INSERT,SELECT, and UPDATE statements.

The gateway does not support Oracle data definition language (DDL) statements. Noform of the Oracle ALTER, CREATE, DROP, GRANT, or TRUNCATE statements can be used.Instead, use the pass-through feature of the gateway if you need to use DDLstatements against the Teradata database.

DELETEThe DELETE statement is fully supported. However, only Oracle functions supportedby Teradata can be used.

INSERTThe INSERT statement is fully supported. However, only Oracle functions supportedby Teradata can be used.

SELECTThe SELECT statement is fully supported, with these exceptions:

■ CONNECT BY condition

■ NOWAIT

■ START WITH condition

■ WHERE CURRENT OF

See Also: Oracle Database SQL Language Reference for detaileddescriptions of keywords, parameters, and options.

See Also: "Functions Supported by Teradata" on page B-2 for alist of supported functions.

See Also: "Functions Supported by Teradata" on page B-2 for alist of supported functions.

Oracle Functions

B-2 Oracle Database Gateway for Teradata User's Guide

UPDATEThe UPDATE statement is fully supported. However, only Oracle functions supportedby Teradata can be used. Also, you cannot have SQL statements in the subquery thatrefer to the same table name in the outer query. Subqueries are not supported in theSET clause.

Oracle FunctionsAll functions are evaluated by the Teradata database after the gateway has convertedthem to Teradata SQL.

Functions Not Supported by TeradataOracle SQL functions with no equivalent function in Teradata are not supported inDELETE, INSERT, or UPDATE statements, but are evaluated by the Oracle database if thestatement is a SELECT statement. That is, the Oracle database performs post-processingof SELECT statements sent to the gateway.

If an unsupported function is used in a DELETE, INSERT, or UPDATE, statement, thefollowing Oracle error occurs:

ORA-02070: database db_link_name does not support function in this context

Functions Supported by TeradataThe gateway translates the following Oracle database functions in SQL statements totheir equivalent Teradata functions:

■ Arithmetic Operators

■ Comparison Operators

■ Group Functions

■ String Functions

■ Other Functions

Arithmetic Operators

Comparison Operators

See Also: "Functions Supported by Teradata" on page B-2 for alist of supported functions.

Oracle Teradata

+ +

- -

* *

/ /

Oracle Teradata

= =

> >

Oracle Functions

Supported SQL Syntax and Functions B-3

Group Functions

String Functions

Other Functions

< <

>= >=

<= <=

<>, !=, ^= <>, !=

IS NOT NULL IS NOT NULL

IS NULL IS NULL

Oracle Teradata

AVG AVG

COUNT COUNT

MAX MAX

MIN MIN

SUM SUM

Oracle Teradata

INSTR POSITION

Oracle Teradata

ABS ABS

EXP EXP

LOG(a, b) LOG10(b) / LOG10(a)

POWER **

SQRT SQRT

Oracle Teradata

Oracle Functions

B-4 Oracle Database Gateway for Teradata User's Guide

C

Data Dictionary C-1

C Data Dictionary

The Oracle Database Gateway for Teradata User's Guide translates a query that refersto an Oracle database data dictionary table into a query that retrieves the data fromTeradata system catalog tables. You perform queries on data dictionary tables over thedatabase link in the same way you query data dictionary tables in the Oracle database.The gateway data dictionary is similar to the Oracle database data dictionary inappearance and use.

This appendix contains the following sections:

■ Data Dictionary Support

■ Data Dictionary Mapping

■ Gateway Data Dictionary Descriptions

Data Dictionary SupportThe following paragraphs describe the Oracle Database Gateway for Teradata datadictionary support.

Teradata System Catalog TablesTeradata data dictionary information is stored in the Teradata database as Teradatasystem catalog tables. The Teradata system catalog tables define the structure of adatabase. When you change data definitions, Teradata reads and modifies the Teradatasystem catalog tables to add information about the user tables.

Accessing the Gateway Data DictionaryAccessing a gateway data dictionary table or view is identical to accessing a datadictionary in an Oracle database. You issue a SQL SELECT statement specifying adatabase link. The Oracle database data dictionary view and column names are usedto access the gateway data dictionary in an Oracle database. Synonyms of supportedviews are also acceptable. For example, the following statement queries the datadictionary table ALL_CATALOG to retrieve all table names in the Teradata database:

SQL> SELECT * FROM ALL_CATALOG@TERA;

When a data dictionary access query is issued, the gateway:

1. Maps the requested table, view, or synonym to one or more Teradata system tablenames. The gateway translates all data dictionary column names to theircorresponding Teradata database column names within the query. Refer to "DataDictionary Mapping" on page C-3 for details.

Data Dictionary Support

C-2 Oracle Database Gateway for Teradata User's Guide

2. Sends the translated query to Teradata.

3. Might convert the retrieved Teradata data to give it the appearance of the Oracledatabase data dictionary table.

4. Passes the data dictionary information from the translated Teradata system catalogtable to the Oracle database.

Direct Queries to Teradata TablesQueries issued directly to individual Teradata system catalog tables are allowed butthey return different results because the Teradata system catalog table column namesdiffer from those of the data dictionary view. Also, certain columns in a Teradatasystem catalog table cannot be used in data dictionary processing.

Supported Views and TablesThe gateway supports the following views and tables:

No other Oracle database data dictionary tables or views are supported. If you use aview not on the list, you receive the Oracle database error code for no more rowsavailable.

Queries through the gateway of any data dictionary table or view beginning withALL_ can returns rows from the Teradata database even when access privileges for

Note: The values returned when querying the gateway datadictionary might not be the same as the ones returned by the OracleEnterprise Manager DESCRIBE command.

Supported Views and Tables Supported Views and Tables

ALL_CATALOG ALL_COL_COMMENTS

ALL_CONS_COLUMNS ALL_CONSTRAINTS

ALL_IND_COLUMNS ALL_INDEXES

ALL_OBJECTS ALL_TAB_COLUMNS

ALL_TAB_COMMENTS ALL_TABLES

ALL_USERS ALL_VIEWS

DBA_CATALOG DBA_COL_COMMENTS

DBA_OBJECTS DBA_TABLES

DBA_TAB_COLUMNS DBA_TAB_COMMENTS

DICT_COLUMNS DICTIONARY

DUAL USER_COL_COMMENTS

USER_CATALOG USER_CONSTRAINTS

USER_CONS_COLUMNS USER_INDEXES

USER_IND_COLUMNS USER_TAB_COLUMNS

USER_OBJECTS USER_TABLES

USER_TAB_COMMENTS USER_VIEWS

USER_USERS

Data Dictionary Mapping

Data Dictionary C-3

those Teradata objects have not been granted. When querying an Oracle database withthe Oracle data dictionary, rows are returned only for those objects you are permittedto access.

Data Dictionary MappingThe tables in this section list Oracle data dictionary view names and the equivalentTeradata system tables used. A plus sign (+) indicates that a join operation is involved.

Table C–1 Oracle Data Dictionary View Names and Teradata Equivalents

View Name Teradata System Table Name

ALL_CATALOG DBC.TablesX + DBC.IndicesX

ALL_COL_COMMENTS DBC.ColumnsX

ALL_CONS_COLUMNS DBC.Indices

ALL_CONSTRAINTS DBC.IndicesX

ALL_IND_COLUMNS DBC.Indices + DBC.Tables + DBC.Columns

ALL_INDEXES DBC.Indices

ALL_OBJECTS DBC.IndicesX + DBC.TablesX

ALL_TAB_COLUMNS DBC.ColumnsX + DBC.TablesX

ALL_TAB_COMMENTS DBC.Tables

ALL_TABLES DBC.TablesX

ALL_USERS DBC.Databases

ALL_VIEWS DBC.Tables

DBA_CATALOG DBC.Tables + DBC.Indices

DBA_COL_COMMENTS DBC.Columns + DBC.Tables

DBA_OBJECTS DBC.Indices + DBC.Tables

DBA_TAB_COLUMNS DBC.Columns + DBC.Tables

DBA_TAB_COMMENTS DBC.Tables

DBA_TABLES DBC.Tables

DICT_COLUMNS DBC.Columns

DICTIONARY DBC.Tables

DUAL DBC.Tables

USER_CATALOG DBC.Tables + DBC.Indices

USER_COL_COMMENTS DBC.Columns

USER_CONS_COLUMNS DBC.Indices

USER_CONSTRAINTS DBC.IndicesX

USER_IND_COLUMNS DBC.Indices + DBC.Tables + DBC.Columns

USER_INDEXES DBC.Indices

USER_OBJECTS DBC.Indices + DBC.Tables

USER_TAB_COLUMNS DBC.ColumnsX + DBC.TablesX

USER_TAB_COMMENTS DBC.TablesX

Gateway Data Dictionary Descriptions

C-4 Oracle Database Gateway for Teradata User's Guide

Default Column ValuesThere is a minor difference between the gateway data dictionary and a typical Oracledatabase data dictionary. The Oracle database columns that are missing in a Teradatasystem catalog table are filled with zeros, spaces, null values, not-applicable values(N.A.), or default values, depending on the column type.

Gateway Data Dictionary DescriptionsThe gateway data dictionary tables and views provide the following information:

■ Name, data type, and width of each column

■ The contents of columns with fixed values

They are described here with information retrieved by an SQL*PLUS DESCRIBEcommand. The values in the Null? column might differ from the Oracle database datadictionary tables and views. Any hardcoded default value is shown to the right of anitem, but this is not information returned by DESCRIBE.

USER_TABLES DBC.Tables

USER_USERS DBC.DatabasesX

USER_VIEWS DBC.Tables

Table C–2 ALL_CATALOG

Name Type Value

OWNER VARCHAR2(30) -

TABLE_NAME VARCHAR2(30) -

TABLE_TYPE VARCHAR2(11) "TABLE","VIEW", or"INDEX"

Table C–3 ALL_COL_COMMENTS

Name Type Value

OWNER VARCHAR2(30) -

TABLE_NAME VARCHAR2(30) -

COLUMN_NAME VARCHAR2(30) -

COMMENTS VARCHAR2(4000) " "

Table C–4 ALL_CONS_COLUMNS

Name Type Value

OWNER VARCHAR2(30) -

CONSTRAINT_NAME VARCHAR2(30) -

TABLE_NAME VARCHAR2(30) -

COLUMN_NAME VARCHAR2(4000) -

Table C–1 (Cont.) Oracle Data Dictionary View Names and Teradata Equivalents

View Name Teradata System Table Name

Gateway Data Dictionary Descriptions

Data Dictionary C-5

POSITION NUMBER -

Table C–5 ALL_CONSTRAINTS

Name Type Value

OWNER VARCHAR2(30) -

CONSTRAINT_NAME VARCHAR2(30) -

CONSTRAINT_TYPE VARCHAR2(1) "R" or "P"

TABLE_NAME VARCHAR2(30) -

SEARCH_CONDITION VARCHAR2(1) " "

R_OWNER VARCHAR2(30) " "

R_CONSTRAINT_NAME VARCHAR2(30) " "

DELETE_RULE VARCHAR2(9) " "

STATUS VARCHAR2(8) " "

DEFERRABLE VARCHAR2(14) " "

DEFERRED VARCHAR2(9) " "

VALIDATED VARCHAR2(13) " "

GENERATED VARCHAR2(14) " "

BAD VARCHAR2(3) " "

RELY VARCHAR2(4) " "

LAST_CHANGE DATE NULL

INDEX_OWNER VARCHAR2(30) " "

INDEX_NAME VARCHAR2(30) " "

INVALID VARCHAR2(7) " "

VIEW_RELATED VARCHAR2(14) " "

Table C–6 ALL_IND_COLUMNS

Name Type Value

INDEX_OWNER VARCHAR2(30) -

INDEX_NAME VARCHAR2(30) -

TABLE_OWNER VARCHAR2(30) -

TABLE_NAME VARCHAR2(30) -

COLUMN_NAME VARCHAR2(4000) -

COLUMN_POSITION NUMBER -

COLUMN_LENGTH NUMBER -

DESCEND VARCHAR2(4) "DESC" or "ASC"

Table C–4 (Cont.) ALL_CONS_COLUMNS

Name Type Value

Gateway Data Dictionary Descriptions

C-6 Oracle Database Gateway for Teradata User's Guide

Table C–7 ALL_INDEXES

Name Type Value

OWNER VARCHAR2(30) -

INDEX_NAME VARCHAR2(30) -

INDEX_TYPE VARCHAR2(27) " "

TABLE_OWNER VARCHAR2(30) -

TABLE_NAME VARCHAR2(30) -

TABLE_TYPE VARCHAR2(5) "TABLE"

UNIQUENESS VARCHAR2(9) "UNIQUE" or"NONUNIQUE"

COMPRESSION VARCHAR2(8) " "

PREFIX_LENGTH NUMBER 0

TABLESPACE_NAME VARCHAR2(30) " "

INI_TRANS NUMBER 0

MAX_TRANS NUMBER(10) 0

INITIAL_EXTENT NUMBER(10) 0

NEXT_EXTENT NUMBER(10) 0

MIN_EXTENTS NUMBER(10) 0

MAX_EXTENTS NUMBER(10) 0

PCT_INCREASE NUMBER(10) 0

PCT_THRESHOLD NUMBER(10) 0

INCLUDE_COLUMN NUMBER(10) 0

FREELISTS NUMBER(10) 0

FREELIST_GROUPS NUMBER(10) 0

PCT_FREE NUMBER(10) 0

LOGGING VARCHAR2(3) " "

BLEVEL NUMBER 0

LEAF_BLOCKS NUMBER 0

DISTINCT_KEYS NUMBER -

AVG_LEAF_BLOCKS_PER_KEY NUMBER 0

AVG_DATA_BLOCKS_PER_KEY NUMBER 0

CLUSTERING_FACTOR NUMBER 0

STATUS CHAR(1) " "

NUM_ROWS NUMBER 0

SAMPLE_SIZE NUMBER 0

LAST_ANALYZED DATE NULL

DEGREE VARCHAR2(40) " "

INSTANCES VARCHAR2(3) " "

PARTITIONED VARCHAR2(3) " "

Gateway Data Dictionary Descriptions

Data Dictionary C-7

TEMPORARY VARCHAR2(1) " "

GENERATED VARCHAR2(1) " "

SECONDARY VARCHAR2(1) " "

BUFFER_POOL VARCHAR2(7) " "

USER_STATS VARCHAR2(3) " "

DURATION VARCHAR2(15) " "

PCT_DIRECT_ACCESS NUMBER 0

ITYP_OWNER VARCHAR2(30) " "

ITYP_NAME VARCHAR2(30) " "

PARAMETERS VARCHAR2(1000) " "

GLOBAL_STATS VARCHAR2(3) " "

DOMIDX_STATUS VARCHAR2(12) " "

DOMIDX_OPSTATUS VARCHAR2(6) " "

FUNCIDX_STATUS VARCHAR2(8) " "

JOIN_INDEX VARCHAR2(3)

IOT_REDUNDANT_PKEY_ELIM VARCHAR2(3)

DROPPED VARCHAR2(3)

VISIBILITY VARCHAR2(9)

DOMIDX_MANAGEMENT VARCHAR2(14)

Table C–8 ALL_OBJECTS

Name Type Value

OWNER VARCHAR2(30) -

OBJECT_NAME VARCHAR2(30) -

SUBOBJECT_NAME VARCHAR2(30) NULL

OBJECT_ID NUMBER 0

DATA_OBJECT_ID NUMBER 0

OBJECT_TYPE VARCHAR2(19) "TABLE" or"VIEW" or"INDEX" or"PROCEDURE"

CREATED DATE NULL

LAST_DDL_TIME DATE NULL

TIMESTAMP VARCHAR2(19) NULL

STATUS VARCHAR2(7) NULL

TEMPORARY VARCHAR2(1) NULL

GENERATED VARCHAR2(1) NULL

SECONDARY VARCHAR2(1) NULL

Table C–7 (Cont.) ALL_INDEXES

Name Type Value

Gateway Data Dictionary Descriptions

C-8 Oracle Database Gateway for Teradata User's Guide

NAMESPACE NUMBER NULL

EDITION_NAME VARCHAR2(30) NULL

Table C–9 ALL_TAB_COLUMNS

Name Type Value

OWNER VARCHAR2(30) -

TABLE_NAME VARCHAR2(30) -

COLUMN_NAME VARCHAR2(30) -

DATA_TYPE VARCHAR2(106) -

DATA_TYPE_MOD VARCHAR2(3) " "

DATA_TYPE_OWNER VARCHAR2(30) " "

DATA_LENGTH NUMBER -

DATA_PRECISION NUMBER -

DATA_SCALE NUMBER -

NULLABLE VARCHAR2(1) "Y" or "N"

COLUMN_ID NUMBER -

DEFAULT_LENGTH NUMBER 0

DATA_DEFAULT VARCHAR2(1024) " "

NUM_DISTINCT NUMBER 0

LOW_VALUE RAW(32) 0

HIGH_VALUE RAW(32) 0

DENSITY NUMBER 0

NUM_NULLS NUMBER 0

NUM_BUCKETS NUMBER 0

LAST_ANALYZED DATE NULL

SAMPLE_SIZE NUMBER 0

CHARACTER_SET_NAME VARCHAR2(44) " "

CHAR_COL_DECL_LENGTH NUMBER 0

GLOBAL_STATS VARCHAR2(3) " "

USER_STATS VARCHAR2(3) " "

AVG_COL_LEN NUMBER 0

CHAR_LENGTH NUMBER

CHAR_USED VARCHAR2(1)

V80_FMT_IMAGE VARCHAR2(3)

DATA_UPGRADED VARCHAR2(3)

HISTOGRAM VARCHAR2(15)

Table C–8 (Cont.) ALL_OBJECTS

Name Type Value

Gateway Data Dictionary Descriptions

Data Dictionary C-9

Table C–10 ALL_TAB_COMMENTS

Name Type Value

OWNER VARCHAR2(30) -

TABLE_NAME VARCHAR2(30) -

TABLE_TYPE VARCHAR2(11) "TABLE" or"VIEW"

COMMENTS VARCHAR2(4000) " "

Table C–11 ALL_TABLES

Name Type Value

OWNER VARCHAR2(30) -

TABLE_NAME VARCHAR2(30) -

TABLESPACE_NAME VARCHAR2(30) " "

CLUSTER_NAME VARCHAR2(30) " "

IOT_NAME VARCHAR2(8) " "

PCT_FREE NUMBER 0

PCT_USED NUMBER 0

INI_TRANS NUMBER 0

MAX_TRANS NUMBER 0

INITIAL_EXTENT NUMBER 0

NEXT_EXTENT NUMBER 0

MIN_EXTENTS NUMBER 0

MAX_EXTENTS NUMBER 0

PCT_INCREASE NUMBER 0

FREELISTS NUMBER 0

FREELIST_GROUPS NUMBER 0

LOGGING VARCHAR2(3) " "

BACKED_UP VARCHAR2(1) " "

NUM_ROWS NUMBER -

BLOCKS NUMBER -

EMPTY_BLOCKS NUMBER 0

AVG_SPACE NUMBER 0

CHAIN_CNT NUMBER 0

AVG_ROW_LEN NUMBER 0

AVG_SPACE_FREELIST_BLOCKS NUMBER 0

NUM_FREELIST_BLOCKS NUMBER 0

DEGREE VARCHAR2(10) " "

INSTANCES VARCHAR2(10) " "

CACHE VARCHAR2(5) " "

Gateway Data Dictionary Descriptions

C-10 Oracle Database Gateway for Teradata User's Guide

TABLE_LOCK VARCHAR2(8) " "

SAMPLE_SIZE NUMBER 0

LAST_ANALYZED DATE NULL

PARTITIONED VARCHAR2(3) " "

IOT_TYPE VARCHAR2(12) " "

TEMPORARY VARCHR2(1) " "

SECONDARY VARCHR2(1) " "

NESTED VARCHAR2(3) " "

BUFFER_POOL VARCHAR2(7) " "

ROW_MOVEMENT VARCHAR2(8) " "

GLOBAL_STATS VARCHAR2(3) " "

USER_STATS VARCHAR2(3) " "

DURATION VARCHAR2(15) " "

SKIP_CORRUPT VARCHAR2(8) " "

MONITORING VARCHAR2(3) " "

CLUSTER_OWNER VARCHAR2(30)

DEPENDENCIES VARCHAR2(8)

COMPRESSION VARCHAR2(8)

DROPPED VARCHAR2(3)

Table C–12 ALL_USERS

Name Type Value

USERNAME VARCHAR2(30) -

USER_ID NUMBER 0

CREATED DATE NULL

Table C–13 ALL_VIEWS

Name Type Value

OWNER VARCHAR2(30) -

VIEW_NAME VARCHAR2(30) -

TEXT_LENGTH NUMBER 0

TEXT VARCHAR2(1) " "

TYPE_TEXT_LENGTH NUMBER 0

TYPE_TEXT VARCHAR2(4000) " "

OID_TEXT_LENGTH NUMBER 0

OID_TEXT VARCHAR2(4000) " "

VIEW_TYPE_OWNER VARCHAR2(30) " "

Table C–11 (Cont.) ALL_TABLES

Name Type Value

Gateway Data Dictionary Descriptions

Data Dictionary C-11

VIEW_TYPE VARCHAR2(30) " "

SUPERVIEW_NAME VARCHAR2(30)

EDITIONING_VIEW VARCHAR2(1)

READ_ONLY VARCHAR2(1)

Table C–14 DBA_CATALOG

Name Type Value

OWNER VARCHAR2(30) -

TABLE_NAME VARCHAR2(30) -

TABLE_TYPE VARCHAR2(11) "TABLE" or"VIEW"

Table C–15 DBA_COL_COMMENTS

Name Type Value

OWNER VARCHAR2(30) -

TABLE_NAME VARCHAR2(30) -

COLUMN_NAME VARCHAR2(30) -

COMMENTS VARCHAR2(4000) " "

Table C–16 DBA_OBJECTS

Name Type Value

OWNER VARCHAR2(30) -

OBJECT_NAME VARCHAR2(128) -

SUBOBJECT_NAME VARCHAR2(30) NULL

OBJECT_ID NUMBER 0

DATA_OBJECT_ID NUMBER 0

OBJECT_TYPE VARCHAR2(19) "TABLE" or"VIEW" or"INDEX" or"PROCEDURE"

CREATED DATE NULL

LAST_DDL_TIME DATE NULL

TIMESTAMP VARCHAR2(19) NULL

STATUS VARCHAR2(7) NULL

TEMPORARY VARCHAR2(1) NULL

GENERATED VARCHAR2(1) NULL

SECONDARY VARCHAR2(1) NULL

NAMESPACE NUMBER

EDITION_NAME VARCHAR2(30)

Table C–13 (Cont.) ALL_VIEWS

Name Type Value

Gateway Data Dictionary Descriptions

C-12 Oracle Database Gateway for Teradata User's Guide

Table C–17 DBA_TAB_COLUMNS

Name Type Value

OWNER VARCHAR2(30) -

TABLE_NAME VARCHAR2(30) -

COLUMN_NAME VARCHAR2(30) -

DATA_TYPE VARCHAR2(106) -

DATA_TYPE_MOD VARCHAR2(3) " "

DATA_TYPE_OWNER VARCHAR2(30) " "

DATA_LENGTH NUMBER -

DATA_PRECISION NUMBER -

DATA_SCALE NUMBER -

NULLABLE VARCHAR2(1) "Y" or "N"

COLUMN_ID NUMBER -

DEFAULT_LENGTH NUMBER 0

DATA_DEFAULT VARCHAR2(1024) " "

NUM_DISTINCT NUMBER 0

LOW_VALUE RAW(32) 0

HIGH_VALUE RAW(32) 0

DENSITY NUMBER 0

NUM_NULLS NUMBER 0

NUM_BUCKETS NUMBER 0

LAST_ANALYZED DATE NULL

SAMPLE_SIZE NUMBER 0

CHARACTER_SET_NAME VARCHAR2(44) " "

CHAR_COL_DECL_LENGTH NUMBER 0

GLOBAL_STATS VARCHAR2(3) " "

USER_STATS VARCHAR2(3) " "

AVG_COL_LEN NUMBER 0

CHAR_LENGTH NUMBER

CHAR_USED VARCHAR2(1)

V80_FMT_IMAGE VARCHAR2(3)

DATA_UPGRADED VARCHAR2(3)

HISTOGRAM VARCHAR2(15)

Table C–18 DBA_TAB_COMMENTS

Name Type Value

OWNER VARCHAR2(30) -

TABLE_NAME VARCHAR2(30) -

Gateway Data Dictionary Descriptions

Data Dictionary C-13

TABLE_TYPE VARCHAR2(11) "TABLE" or"VIEW"

COMMENTS VARCHAR2(4000) " "

Table C–19 DBA_TABLES

Name Type Value

OWNER VARCHAR2(30) -

TABLE_NAME VARCHAR2(30) -

TABLESPACE_NAME VARCHAR2(30) " "

CLUSTER_NAME VARCHAR2(30) " "

IOT_NAME VARCHAR2(30) " "

STATUS VARCHAR2(8)

PCT_FREE NUMBER 0

PCT_USED NUMBER 0

INI_TRANS NUMBER 0

MAX_TRANS NUMBER 0

INITIAL_EXTENT NUMBER 0

NEXT_EXTENT NUMBER 0

MIN_EXTENTS NUMBER 0

MAX_EXTENTS NUMBER 0

PCT_INCREASE NUMBER 0

FREELISTS NUMBER 0

FREELIST_GROUPS NUMBER 0

LOGGING VARCHAR2(3) " "

BACKED_UP VARCHAR2(1) " "

NUM_ROWS NUMBER -

BLOCKS NUMBER -

EMPTY_BLOCKS NUMBER 0

AVG_SPACE NUMBER 0

CHAIN_CNT NUMBER 0

AVG_ROW_LEN NUMBER 0

AVG_SPACE_FREELIST_BLOCKS NUMBER 0

NUM_FREELIST_BLOCKS NUMBER 0

DEGREE VARCHAR2(10) " "

INSTANCES VARCHAR2(10) " "

CACHE VARCHAR2(5) " "

TABLE_LOCK VARCHAR2(8) " "

Table C–18 (Cont.) DBA_TAB_COMMENTS

Name Type Value

Gateway Data Dictionary Descriptions

C-14 Oracle Database Gateway for Teradata User's Guide

SAMPLE_SIZE NUMBER 0

LAST_ANALYZED DATE NULL

PARTITIONED VARCHAR2(3) " "

IOT_TYPE VARCHAR2(12) " "

TEMPORARY VARCHAR2(1) " "

SECONDARY VARCHAR2(1) " "

NESTED VARCHAR2(3) " "

BUFFER_POOL VARCHAR2(7) " "

ROW_MOVEMENT VARCHAR2(8) " "

GLOBAL_STATS VARCHAR2(3) " "

USER_STATS VARCHAR2(3) " "

DURATION VARCHAR2(15) " "

SKIP_CORRUPT VARCHAR2(8) " "

MONITORING VARCHAR2(3) " "

CLUSTER_OWNER VARCHAR2(30)

DEPENDENCIES VARCHAR2(8)

COMPRESSION VARCHAR2(8)

DROPPED VARCHAR2(3)

Table C–20 DICT_COLUMNS

Name Type Value

TABLE_NAME VARCHAR2(30) -

COLUMN_NAME VARCHAR2(30) -

COMMENTS VARCHAR2(4000) " "

Table C–21 DICTIONARY

Name Type Value

TABLE_NAME VARCHAR2(30) -

COMMENTS VARCHAR2(4000) " "

Table C–22 DUAL

Name Type Value

DUMMY VARCHAR2(1) "X"

Table C–23 USER_CATALOG

Name Type Value

TABLE_NAME VARCHAR2(30) -

Table C–19 (Cont.) DBA_TABLES

Name Type Value

Gateway Data Dictionary Descriptions

Data Dictionary C-15

TABLE_TYPE VARCHAR2(11) "TABLE" or"VIEW"

Table C–24 USER_COL_COMMENTS

Name Type Value

TABLE_NAME VARCHAR2(30) -

COLUMN_NAME VARCHAR2(30) -

COMMENTS VARCHAR2(4000) " "

Table C–25 USER_CONS_COLUMNS

Name Type Value

OWNER VARCHAR2(30) -

CONSTRAINT_NAME VARCHAR2(30) -

TABLE_NAME VARCHAR2(30) -

COLUMN_NAME VARCHAR2(4000) -

POSITION NUMBER -

Table C–26 USER_CONSTRAINTS

Name Type Value

OWNER VARCHAR2(30) -

CONSTRAINT_NAME VARCHAR2(30) -

CONSTRAINT_TYPE VARCHAR2(1) "R" or "P"

TABLE_NAME VARCHAR2(30) -

SEARCH_CONDITION CHAR(1) " "

R_OWNER VARCHAR2(30) -

R_CONSTRAINT_NAME VARCHAR2(30) -

DELETE_RULE VARCHAR2(9) " "

STATUS VARCHAR2(8) " "

DEFERRABLE VARCHAR2(14) " "

DEFERRED VARCHAR2(9) " "

VALIDATED VARCHAR2(13) " "

GENERATED VARCHAR2(14) " "

BAD VARCHAR2(3) " "

RELY VARCHAR2(4) " "

LAST_CHANGE DATE NULL

INDEX_OWNER VARCHAR2(30)

INDEX_NAME VARCHAR2(30)

INVALID VARCHAR2(7)

Table C–23 (Cont.) USER_CATALOG

Name Type Value

Gateway Data Dictionary Descriptions

C-16 Oracle Database Gateway for Teradata User's Guide

VIEW_RELATED VARCHAR2(14)

Table C–27 USER_IND_COLUMNS

Name Type Value

INDEX_NAME VARCHAR2(30) -

TABLE_NAME VARCHAR2(30) -

COLUMN_NAME VARCHAR2(4000) -

COLUMN_POSITION NUMBER -

COLUMN_LENGTH NUMBER -

CHAR_LENGTH NUMBER

DESCEND VARCHAR2(4) "DESC" or "ASC"

Table C–28 USER_INDEXES

Name Type Value

INDEX_NAME VARCHAR2(30) -

INDEX_TYPE VARCHAR2(27) " "

TABLE_OWNER VARCHAR2(30) -

TABLE_NAME VARCHAR2(30) -

TABLE_TYPE VARCHAR2(11) "TABLE"

UNIQUENESS VARCHAR2(9) "UNIQUE" or"NONUNIQUE"

COMPRESSION VARCHAR2(8) " "

PREFIX_LENGTH NUMBER 0

TABLESPACE_NAME VARCHAR2(30) " "

INI_TRANS NUMBER 0

MAX_TRANS NUMBER 0

INITIAL_EXTENT NUMBER 0

NEXT_EXTENT NUMBER 0

MIN_EXTENTS NUMBER 0

MAX_EXTENTS NUMBER 0

PCT_INCREASE NUMBER 0

PCT_THRESHOLD NUMBER 0

INCLUDE_COLUMN NUMBER 0

FREELISTS NUMBER 0

FREELIST_GROUPS NUMBER 0

PCT_FREE NUMBER 0

LOGGING VARCHAR2(3) " "

Table C–26 (Cont.) USER_CONSTRAINTS

Name Type Value

Gateway Data Dictionary Descriptions

Data Dictionary C-17

BLEVEL NUMBER 0

LEAF_BLOCKS NUMBER 0

DISTINCT_KEYS NUMBER -

AVG_LEAF_BLOCKS_PER_KEY NUMBER 0

AVG_DATA_BLOCKS_PER_KEY NUMBER 0

CLUSTERING_FACTOR NUMBER 0

STATUS VARCHAR2(8) " "

NUM_ROWS NUMBER 0

SAMPLE_SIZE NUMBER 0

LAST_ANALYZED DATE NULL

DEGREE VARCHAR2(40) " "

INSTANCES VARCHAR2(40) " "

PARTITIONED VARCHAR2(3) " "

TEMPORARY VARCHAR2(1) " "

GENERATED VARCHAR2(1) " "

SECONDARY VARCHAR2(1) " "

BUFFER_POOL VARCHAR2(7) " "

USER_STATS VARCHAR2(3) " "

DURATION VARCHAR2(15) " "

PCT_DIRECT_ACCESS NUMBER 0

ITYP_OWNER VARCHAR2(30) " "

ITYP_NAME VARCHAR2(30) " "

PARAMETERS VARCHAR2(1000) " "

GLOBAL_STATS VARCHAR2(3) " "

DOMIDX_STATUS VARCHAR2(12) " "

DOMIDX_OPSTATUS VARCHAR2(6) " "

FUNCIDX_STATUS VARCHAR2(8) " "

JOIN_INDEX VARCHAR2(3)

IOT_REDUNDANT_PKEY_ELIM VARCHAR2(3)

DROPPED VARCHAR2(3)

VISIBILITY VARCHAR2(10)

DOMIDX_MANAGEMENT VARCHAR2(14)

Table C–29 USER_OBJECTS

Name Type Value

OBJECT_NAME VARCHAR2(128) -

SUBOBJECT_NAME VARCHAR2(30) NULL

Table C–28 (Cont.) USER_INDEXES

Name Type Value

Gateway Data Dictionary Descriptions

C-18 Oracle Database Gateway for Teradata User's Guide

OBJECT_ID NUMBER 0

DATA_OBJECT_ID NUMBER 0

OBJECT_TYPE VARCHAR2(19) "TABLE" or"VIEW" or"INDEX" or"PROCEDURE"

CREATED DATE NULL

LAST_DDL_TIME DATE NULL

TIMESTAMP VARCHAR2(19) NULL

STATUS VARCHAR2(7) NULL

TEMPORARY VARCHAR2(1) NULL

GENERATED VARCHAR2(1) NULL

SECONDARY VARCHAR2(1) NULL

NAMESPACE NUMBER

EDITION_NAME VARCHAR2(30)

Table C–30 USER_TAB_COLUMNS

Name Type Value

TABLE_NAME VARCHAR2(30) -

COLUMN_NAME VARCHAR2(30) -

DATA_TYPE VARCHAR2(106) -

DATA_TYPE_MOD VARCHAR2(3) " "

DATA_TYPE_OWNER VARCHAR2(30) " "

DATA_LENGTH NUMBER -

DATA_PRECISION NUMBER -

DATA_SCALE NUMBER -

NULLABLE VARCHAR2(1) "Y" or "N"

COLUMN_ID NUMBER -

DEFAULT_LENGTH NUMBER 0

DATA_DEFAULT CHAR(1) " "

NUM_DISTINCT NUMBER 0

LOW_VALUE RAW(32) 0

HIGH_VALUE RAW(32) 0

DENSITY NUMBER 0

NUM_NULLS NUMBER 0

NUM_BUCKETS NUMBER 0

LAST_ANALYZED DATE NULL

SAMPLE_SIZE NUMBER 0

Table C–29 (Cont.) USER_OBJECTS

Name Type Value

Gateway Data Dictionary Descriptions

Data Dictionary C-19

CHARACTER_SET_NAME VARCHAR2(44) " "

CHAR_COL_DECL_LENGTH NUMBER 0

GLOBAL_STATS VARCHAR2(3) " "

USER_STATS VARCHAR2(3) " "

AVG_COL_LEN NUMBER 0

CHAR_LENGTH NUMBER

CHAR_USED VARCHAR2(1)

V80_FMT_IMAGE VARCHAR2(3)

DATA_UPGRADED VARCHAR2(3)

HISTOGRAM VARCHAR2(15)

Table C–31 USER_TAB_COMMENTS

Name Type Value

TABLE_NAME VARCHAR2(30) -

TABLE_TYPE VARCHAR2(11) "TABLE" or"VIEW"

COMMENTS VARCHAR2(4000) " "

Table C–32 USER_TABLES

Name Type Value

TABLE_NAME VARCHAR2(30) -

TABLESPACE_NAME VARCHAR2(30) " "

CLUSTER_NAME VARCHAR2(30) " "

IOT_NAME VARCHAR2(30) " "

STATUS VARCHAR2(8)

PCT_FREE NUMBER 0

PCT_USED NUMBER 0

INI_TRANS NUMBER 0

MAX_TRANS NUMBER 0

INITIAL_EXTENT NUMBER 0

NEXT_EXTENT NUMBER 0

MIN_EXTENTS NUMBER 0

MAX_EXTENTS NUMBER 0

PCT_INCREASE NUMBER 0

FREELISTS NUMBER 0

FREELIST_GROUPS NUMBER 0

LOGGING VARCHAR2(3) " "

Table C–30 (Cont.) USER_TAB_COLUMNS

Name Type Value

Gateway Data Dictionary Descriptions

C-20 Oracle Database Gateway for Teradata User's Guide

BACKED_UP VARCHAR2(1) " "

NUM_ROWS NUMBER -

BLOCKS NUMBER -

EMPTY_BLOCKS NUMBER 0

AVG_SPACE NUMBER 0

CHAIN_CNT NUMBER 0

AVG_ROW_LEN NUMBER 0

AVG_SPACE_FREELIST_BLOCKS NUMBER 0

NUM_FREELIST_BLOCKS NUMBER 0

DEGREE VARCHAR2(10) " "

INSTANCES VARCHAR2(10) " "

CACHE VARCHAR2(5) " "

TABLE_LOCK VARCHAR2(8) " "

SAMPLE_SIZE NUMBER 0

LAST_ANALYZED DATE NULL

PARTITIONED VARCHAR2(3) " "

IOT_TYPE VARCHAR2(12) " "

TEMPORARY VARCHAR2(1) " "

SECONDARY VARCHAR2(1) " "

NESTED VARCHAR2(3) " "

BUFFER_POOL VARCHAR2(7) " "

ROW_MOVEMENT VARCHAR2(8) " "

GLOBAL_STATS VARCHAR2(3) " "

USER_STATS VARCHAR2(3) " "

DURATION VARCHAR2(15) " "

SKIP_CORRUPT VARCHAR2(8) " "

MONITORING VARCHAR2(3) " "

Table C–33 USER_USERS

Name Type Value

USERNAME VARCHAR2(30) -

USER_ID NUMBER 0

ACCOUNT_STATUS VARCHAR2(32) "OPEN"

LOCK_DATE DATE NULL

EXPIRY_DATE DATE NULL

DEFAULT_TABLESPACE VARCHAR2(30) NULL

TEMPORARY_TABLESPACE VARCHAR2(30) NULL

Table C–32 (Cont.) USER_TABLES

Name Type Value

Gateway Data Dictionary Descriptions

Data Dictionary C-21

CREATED DATE NULL

INITIAL_RSRC_CONSUMER_GROUP VARCHAR2(30) NULL

EXTERNAL_NAME VARCHAR2(4000) NULL

Table C–34 USER_VIEWS

Name Type Value

VIEW_NAME VARCHAR2(30) -

TEXT_LENGTH NUMBER 0

TEXT CHAR(1) " "

TYPE_TEXT_LENGTH NUMBER 0

TYPE_TEXT VARCHAR2(4000) " "

OID_TEXT_LENGTH NUMBER 0

OID_TEXT VARCHAR2(4000) " "

VIEW_TYPE_OWNER VARCHAR2(30) " "

VIEW_TYPE VARCHAR2(30) " "

SUPERVIEW_NAME VARCHAR2(30)

EDITIONING_VIEW VARCHAR2(1)

Table C–33 (Cont.) USER_USERS

Name Type Value

Gateway Data Dictionary Descriptions

C-22 Oracle Database Gateway for Teradata User's Guide

D

Initialization Parameters D-1

D Initialization Parameters

The Oracle database initialization parameters in the init.ora file are distinct fromgateway initialization parameters. Set the gateway parameters in the initializationparameter file using an agent-specific mechanism, or set them in the Oracle datadictionary using the DBMS_HS package. The gateway initialization parameter file mustbe available when the gateway is started.

This appendix contains a list of the gateway initialization parameters that can be setfor each gateway and their description. It also describes the initialization parameterfile syntax. It includes the following sections:

■ Initialization Parameter File Syntax

■ Oracle Database Gateway for Teradata Initialization Parameters

■ Initialization Parameter Descriptions

Initialization Parameter File SyntaxThe syntax for the initialization parameter file is as follows:

1. The file is a sequence of commands.

2. Each command should start on a separate line.

3. End of line is considered a command terminator (unless escaped with abackslash).

4. If there is a syntax error in an initialization parameter file, none of the settings takeeffect.

5. Set the parameter values as follows:

[SET][PRIVATE] parameter=value

Where:

parameter is an initialization parameter name. It is a string of characters startingwith a letter and consisting of letters, digits and underscores. Initializationparameter names are case sensitive.

value is the initialization parameter value. It is case sensitive. An initializationparameter value is either:

a. A string of characters that does not contain any backslashes, white space ordouble quotation marks (")

b. A quoted string beginning with a double quotation mark and ending with adouble quotation mark. The following can be used inside a quoted string:

Oracle Database Gateway for Teradata Initialization Parameters

D-2 Oracle Database Gateway for Teradata User's Guide

* backslash (\) is the escape character

* \n inserts a new line

* \t inserts a tab

* \" inserts a double quotation mark

* \\ inserts a backslash

A backslash at the end of the line continues the string on the next line. If abackslash precedes any other character then the backslash is ignored.

For example, to enable tracing for an agent, set the HS_FDS_TRACE_LEVELinitialization parameter as follows:

HS_FDS_TRACE_LEVEL=ON

SET and PRIVATE are optional keywords. You cannot use either as an initializationparameter name. Most parameters are needed only as initialization parameters, soyou usually do not need to use the SET or PRIVATE keywords. If you do not specifyeither SET or PRIVATE, the parameter is used only as an initialization parameter forthe agent.

SET specifies that, in addition to being used as an initialization parameter, theparameter value is set as an environment variable for the agent process. Use SETfor parameter values that the drivers or non-Oracle system need as environmentvariables.

PRIVATE specifies that the initialization parameter should be private to the agentand should not be uploaded to the Oracle database. Most initialization parametersshould not be private. If, however, you are storing sensitive information like apassword in the initialization parameter file, then you may not want it uploadedto the server because the initialization parameters and values are not encryptedwhen uploaded. Making the initialization parameters private prevents the uploadfrom happening and they do not appear in dynamic performance views. UsePRIVATE for the initialization parameters only if the parameter value includessensitive information such as a user name or password.

SET PRIVATE specifies that the parameter value is set as an environment variablefor the agent process and is also private (not transferred to the Oracle database,not appearing in dynamic performance views or graphical user interfaces).

Oracle Database Gateway for Teradata Initialization ParametersThis section lists all the initialization file parameters that can be set for the OracleDatabase Gateway for Teradata. They are as follows:

■ HS_DB_DOMAIN

■ HS_DB_INTERNAL_NAME

■ HS_DB_NAME

■ HS_DESCRIBE_CACHE_HWM

■ HS_LANGUAGE

■ HS_LONG_PIECE_TRANSFER_SIZE

■ HS_OPEN_CURSORS

■ HS_RPC_FETCH_REBLOCKING

■ HS_RPC_FETCH_SIZE

Initialization Parameter Description

Initialization Parameters D-3

■ HS_TIME_ZONE

■ HS_TRANSACTION_MODEL

■ IFILE

■ HS_FDS_TIMESTAMP_MAPPING

■ HS_FDS_DATE_MAPPING

■ HS_FDS_CONNECT_INFO

■ HS_FDS_DEFAULT_OWNER

■ HS_FDS_PROC_IS_FUNC

■ HS_FDS_RECOVERY_ACCOUNT

■ HS_FDS_RECOVERY_PWD

■ HS_FDS_TRACE_LEVEL

■ HS_FDS_TRANSACTION_LOG

■ HS_FDS_FETCH_ROWS

■ HS_IDLE_TIMEOUT

■ HS_NLS_LENGTH_SEMANTICS

■ HS_KEEP_REMOTE_COLUMN_SIZE

■ HS_FDS_REMOTE_DB_CHARSET

■ HS_FDS_SUPPORT_STATISTICS

■ HS_FDS_ARRAY_EXEC

Initialization Parameter DescriptionThe following sections describe all the initialization file parameters that can be set forgateways.

HS_DB_DOMAIN

Specifies a unique network sub-address for a non-Oracle system. The HS_DB_DOMAINinitialization parameter is similar to the DB_DOMAIN initialization parameter, describedin the Oracle Database Reference. The HS_DB_DOMAIN initialization parameter is requiredif you use the Oracle Names server. The HS_DB_NAME and HS_DB_DOMAIN initializationparameters define the global name of the non-Oracle system.

Property Description

Default value WORLD

Range of values 1 to 199 characters

Note: The HS_DB_NAME and HS_DB_DOMAIN initialization parametersmust combine to form a unique address in a cooperative serverenvironment.

Initialization Parameter Description

D-4 Oracle Database Gateway for Teradata User's Guide

HS_DB_INTERNAL_NAME

Specifies a unique hexadecimal number identifying the instance to which theHeterogeneous Services agent is connected. This parameter's value is used as part of atransaction ID when global name services are activated. Specifying a nonuniquenumber can cause problems when two-phase commit recovery actions are necessaryfor a transaction.

HS_DB_NAME

Specifies a unique alphanumeric name for the data store given to the non-Oraclesystem. This name identifies the non-Oracle system within the cooperative serverenvironment. The HS_DB_NAME and HS_DB_DOMAIN initialization parameters define theglobal name of the non-Oracle system.

HS_DESCRIBE_CACHE_HWM

Specifies the maximum number of entries in the describe cache used byHeterogeneous Services. This limit is known as the describe cache high water mark.The cache contains descriptions of the mapped tables that Heterogeneous Servicesreuses so that it does not have to re-access the non-Oracle data store.

If you are accessing many mapped tables, increase the high water mark to improveperformance. Increasing the high water mark improves performance at the cost ofmemory usage.

HS_LANGUAGE

Provides Heterogeneous Services with character set, language, and territoryinformation of the non-Oracle data source. The value must use the following format:

language[_territory.character_set]

Property Description

Default value 01010101

Range of values 1 to 16 hexadecimal characters

Property Description

Default value HO

Range of values 1 to 8 characters

Property Description

Default value 100

Range of values 1 to 4000

Property Description

Default value System-specific

Range of values Any valid language name (up to 255 characters)

Initialization Parameter Description

Initialization Parameters D-5

Character SetsIdeally, the character sets of the Oracle database and the non-Oracle data source arethe same. In almost all cases, HS_LANGUAGE should be set exactly the same as Oracledatabase character set for optimal character set mapping and performance. If they arenot the same, Heterogeneous Services attempts to translate the character set of thenon-Oracle data source to the Oracle database character set, and back again. Thetranslation can degrade performance. In some cases, Heterogeneous Services cannottranslate a character from one character set to another.

As more Oracle databases and non-Oracle databases use Unicode as databasecharacter sets, it is preferable to also run the gateway in Unicode character set. To doso, you must set HS_LANGUAGE=AL32UTF8. However, when the gateway runs onWindows, the Microsoft ODBC Driver Manager interface can exchange data only inthe double-byte character set, UCS2. This results in extra ratio expansion of describedbuffer and column sizes. Refer to HS_FDS_REMOTE_DB_CHARSET for instruction onhow to adjust to correct sizes.

LanguageThe language component of the HS_LANGUAGE initialization parameter determines:

■ Day and month names of dates

■ AD, BC, PM, and AM symbols for date and time

■ Default sorting mechanism

Note that Oracle does not determine the language for error messages for the genericHeterogeneous Services messages (ORA-25000 through ORA-28000). These arecontrolled by the session settings in the Oracle database.

TerritoryThe territory clause specifies the conventions for day and week numbering, defaultdate format, decimal character and group separator, and ISO and local currencysymbols. Note that the level of globalization support between the Oracle database andthe non-Oracle data source depends on how the gateway is implemented.

HS_LONG_PIECE_TRANSFER_SIZE

Note: The globalization support initialization parameters affecterror messages, the data for the SQL Service, and parameters indistributed external procedures.

Note: The specified character set must be a superset of theoperating system character set on the platform where the agent isinstalled.

Property Description

Default value 64 KB

Range of values Any value up to 2 GB

Initialization Parameter Description

D-6 Oracle Database Gateway for Teradata User's Guide

Sets the size of the piece of LONG data being transferred. A smaller piece size means lessmemory requirement, but more round-trips to fetch all the data. A larger piece sizemeans fewer round-trips, but more of a memory requirement to store the intermediatepieces internally. Thus, the initialization parameter can be used to tune a system forthe best performance, with the best trade-off between round-trips and memoryrequirements, and network latency or response time.

HS_OPEN_CURSORS

Defines the maximum number of cursors that can be open on one connection to anon-Oracle system instance.

The value never exceeds the number of open cursors in the Oracle database. Therefore,setting the same value as the OPEN_CURSORS initialization parameter in the Oracledatabase is recommended.

HS_RPC_FETCH_REBLOCKING

Controls whether Heterogeneous Services attempts to optimize performance of datatransfer between the Oracle database and the Heterogeneous Services agent connectedto the non-Oracle data store.

The following values are possible:

■ OFF disables reblocking of fetched data so that data is immediately sent from agentto server.

■ ON enables reblocking, which means that data fetched from the non-Oracle systemis buffered in the agent and is not sent to the Oracle database until the amount offetched data is equal or higher than the value of HS_RPC_FETCH_SIZE initializationparameter. However, any buffered data is returned immediately when a fetchindicates that no more data exists or when the non-Oracle system reports an error.

HS_RPC_FETCH_SIZE

Tunes internal data buffering to optimize the data transfer rate between the server andthe agent process.

Property Description

Default value 50

Range of values 1 to the value of Oracle's OPEN_CURSORS initialization parameter

Property Description

Default value ON

Range of values OFF or ON

Property Description

Default value 50000

Range of values 1 to 10000000

Initialization Parameter Description

Initialization Parameters D-7

Increasing the value can reduce the number of network round-trips needed to transfera given amount of data, but also tends to increase data bandwidth and to reducelatency as measured between issuing a query and completion of all fetches for thequery. Nevertheless, increasing the fetch size can increase latency for the initial fetchresults of a query, because the first fetch results are not transmitted until additionaldata is available.

HS_TIME_ZONE

Specifies the default local time zone displacement for the current SQL session. Theformat mask, [+|-]hh:mm, is specified to indicate the hours and minutes before orafter UTC (Coordinated Universal Time—formerly Greenwich Mean Time). Forexample:

HS_TIME_ZONE = [+ | -] hh:mm

HS_TRANSACTION_MODEL

Specifies the type of transaction model that is used when the non-Oracle database isupdated by a transaction.

The following values are possible:

■ COMMIT_CONFIRM provides read and write access to the non-Oracle database andallows the gateway to be part of a distributed update. To use the commit-confirmmodel, the following items must be created in the non-Oracle database:

– Transaction log table. The default table name is HS_TRANSACTION_LOG. Adifferent name can be set using the HS_FDS_TRANSACTION_LOG parameter. Thetransaction log table must be granted SELECT, DELETE, and INSERT privilegesset to public.

– Recovery account. The account name is assigned with the HS_FDS_RECOVERY_ACCOUNT parameter.

– Recovery account password. The password is assigned with the HS_FDS_RECOVERY_PWD parameter.

■ READ_ONLY provides read access to the non-Oracle database.

■ SINGLE_SITE provides read and write access to the non-Oracle database. However,the gateway cannot participate in distributed updates.

■ READ_ONLY_AUTOCOMMIT provides read only access to the non-Oracle database thatdoes not use logging.

Property Description

Default value for'[+|-]hh:mm'

Derived from the NLS_TERRITORY initialization parameter

Range of values for'[+|-]hh:mm'

Any valid datetime format mask

Property Description

Default Value COMMIT_CONFIRM

Range of Values COMMIT_CONFIRM, READ_ONLY, SINGLE_SITE, READ_ONLY_AUTOCOMMIT, SINGLE_SITE_AUTOCOMMIT

Initialization Parameter Description

D-8 Oracle Database Gateway for Teradata User's Guide

■ SINGLE_SITE_AUTOCOMMIT provides read and write access to the non-Oracledatabase without logging. The gateway cannot participate in distributed updates.Moreover, any update to the non-Oracle database is committed immediately.

IFILE

Use the IFILE initialization parameter to embed another initialization file within thecurrent initialization file. The value should be an absolute path and should not containenvironment variables. The three levels of nesting limit do not apply.

HS_FDS_TIMESTAMP_MAPPING

If set to CHAR (default), non-Oracle target timestamp would be mapped to CHAR(26). Ifset to DATE, then non-Oracle target timestamp would be mapped to Oracle date. If setto TIMESTAMP, non-Oracle target timestamp would be mapped to Oracle timestamp.

HS_FDS_DATE_MAPPING

If set to CHAR, then non-oracle target date would be mapped to CHAR(10). If set to DATE,then non-Oracle target date would be mapped to Oracle date.

HS_FDS_CONNECT_INFO

HS_FDS_CONNECT_INFO that describes the connection to the non-Oracle system.

Property Description

Default value None

Range of values Valid parameter file names

See Also: Oracle Database Reference

Property Description

Default Value DATE

Range of Values CHAR|DATE|TIMESTAMP

Syntax HS_FDS_TIMESTAMP_MAPPING={CHAR|DATE|TIMESTAMP}

Property Description

Default Value DATE

Range of Values DATE|CHAR

Syntax HS_FDS_DATE_MAPPING={DATE|CHAR}

Property Description

Default Value None

Range of Values Not applicable

Initialization Parameter Description

Initialization Parameters D-9

The default initialization parameter file already has an entry for this parameter. Thesyntax for HS_FDS_CONNECT_INFO for the gateway is as follows:

HS_FDS_CONNECT_INFO=host_alias:port_number[/database_name]

where, host_alias is the host alias name or IP address of the machine hosting theTeradata database, port_number is the port number of the Teradata database server,and database_name is the Teradata database name. The database_name variable isoptional.

This release supports IPv6 format, so you can enter IPv6 format in place of hostname,but you need to wrap square brackets around the IPv6 specification.

For example,

HS_FDS_CONNECT_INFO=[2001:0db8:20c:f1ff:fec6:38af]:port_number/…

HS_FDS_DEFAULT_OWNER

The name of the table owner that is used for the non-Oracle database tables if anowner is not specified in the SQL statements.

HS_FDS_PROC_IS_FUNC

Enables return values from functions. By default, all stored procedures and functionsdo not return a return value to the user.

HS_FDS_RECOVERY_ACCOUNT

Property Description

Default Value None

Range of Values Not applicable

Note: If this parameter is not specified and the owner is notexplicitly specified in the SQL statement, then the user name of theOracle user or the user name specified when creating the databaselink is used.

Property Description

Default Value FALSE

Range of Values TRUE, FALSE

Note: If you set this initialization parameter, you must change thesyntax of the procedure execute statement for all existing storedprocedures to handle return values.

Property Description

Default Value RECOVER

Initialization Parameter Description

D-10 Oracle Database Gateway for Teradata User's Guide

Specifies the name of the recovery account used for the commit-confirm transactionmodel. An account with user name and password must be set up at the non-Oraclesystem. For more information about the commit-confirm model, see the HS_TRANSACTION_MODEL parameter.

The name of the recovery account is case sensitive.

HS_FDS_RECOVERY_PWD

Specifies the password of the recovery account used for the commit-confirmtransaction model set up at the non-Oracle system. For more information about thecommit-confirm model, see the HS_TRANSACTION_MODEL parameter.

The name of the password of the recovery account is case sensitive.

HS_FDS_TRACE_LEVEL

Specifies whether error tracing is turned on or off for gateway connectivity.

The following values are valid:

■ OFF disables the tracing of error messages.

■ ON enables the tracing of error messages that occur when you encounter problems.The results are written by default to a gateway log file in LOG directory where thegateway is installed.

■ DEBUG enables the tracing of detailed error messages that can be used fordebugging.

HS_FDS_TRANSACTION_LOG

Specifies the name of the table created in the non-Oracle system for loggingtransactions. For more information about the transaction model, see the HS_TRANSACTION_MODEL parameter.

Range of values Any valid user ID

Property Description

Default Value RECOVER

Range of values Any valid password

Property Description

Default Value OFF

Range of values OFF, ON, DEBUG

Property Description

Default Value HS_TRANSACTION_LOG

Range of Values Any valid table name

Property Description

Initialization Parameter Description

Initialization Parameters D-11

HS_FDS_FETCH_ROWS

HS_FDS_FETCH_ROWS specifies the fetch array size. This is the number of rows to befetched from the non-Oracle database and to return to Oracle database at one time.This parameter will be affected by the HS_RPC_FETCH_SIZE and HS_RPC_FETCH_REBLOCKING parameters.

HS_IDLE_TIMEOUT

This feature is only available for Oracle Net TCP protocol. When there is no activity fora connected gateway session for this specified time period, the gateway session wouldbe terminated automatically with pending update (if any) rolled back.

HS_NLS_LENGTH_SEMANTICS

This release of gateway has Character Semantics functionality equivalent to the OracleDatabase Character Semantics, that is, NLS_LENGTH_SEMANTICS. When HS_NLS_LENGTH_SEMANTICS is set to CHAR, the (VAR)CHAR columns of Teradata are to be interpreted ashaving CHAR semantics. The only situation the gateway does not honor the HS_NLS_LENGTH_SEMANTICS=CHAR setting is when both Oracle database and the gateway are onthe same multi-byte character set

HS_KEEP_REMOTE_COLUMN_SIZE

Property Description

Default Value 100

Range of Values Any integer between 1 and 1000

Syntax HS_FDS_FETCH_ROWS=num

Property Description

Default Value 0 (no timeout)

Range of Values 0-9999 (minutes)

Syntax HS_IDLE_TIMEOUT=num

Property Description

Default Value BYTE

Range of Values BYTE | CHAR

Syntax HS_NLS_LENGTH_SEMANTICS = { BYTE | CHAR }

Property Description

Default Value OFF

Range of Values OFF | LOCAL | REMOTE |ALL

Syntax HS_KEEP_REMOTE_COLUMN_SIZE = OFF | LOCAL | REMOTE| ALL

Parameter type String

Initialization Parameter Description

D-12 Oracle Database Gateway for Teradata User's Guide

HS_KEEP_REMOTE_COLUMN_SIZE specifies whether to suppress ratio expansion whencomputing the length of (VAR)CHAR datatypes during data conversion from non-Oracledatabase to the gateway, and then to the Oracle database. When it is set to REMOTE, theexpansion is suppressed between the non-Oracle database and the gateway. When it isset to LOCAL, the expansion is suppressed between the gateway and the Oracledatabase. When it is set to ALL, the expansion is suppressed from the non-Oracledatabase to the Oracle database.

When the parameter is set, the expansion is suppressed when reporting the remotecolumn size, calculating the implicit resulting buffer size, and instantiating in the localOracle database. This has effect only for remote column size from non-Oracle databaseto the Oracle database. If the gateway runs on Windows and HS_LANGUAGE=AL32UTF8,then you must not specify this parameter, as it would influence other ratio relatedparameter operation. It has no effect for calculating ratio for data moving from Oracledatabase to non-Oracle database through gateway during INSERT, UPDATE, or DELETE.

HS_FDS_REMOTE_DB_CHARSET

This parameter is valid only when HS_LANGUAGE is set to AL32UTF8 and the gatewayruns on Windows. As more Oracle databases and non-Oracle databases use Unicode asdatabase character sets, it is preferable to also run the gateway in Unicode characterset. To do so, you must set HS_LANGUAGE=AL32UTF8. However, when the gateway runson Windows, the Microsoft ODBC Driver Manager interface can exchange data only inthe double-byte character set, UCS2. This results in extra ratio expansion of describedbuffer and column sizes. To compensate, the gateway can re-adjust the column size ifHS_FDS_REMOTE_DB_CHARSET is set to the corresponding non-Oracle database characterset. For example, HS_FDS_REMOTE_DB_CHARSET=KO16KSC5601.

HS_FDS_SUPPORT_STATISTICS

We gather statistics from the non-Oracle database by default. You can choose to disablethe gathering of remote database statistics by setting the HS_FDS_SUPPORT_STATISTICSparameter to FALSE.

HS_FDS_ARRAY_EXEC

Property Description

Default Value None

Range of values Not applicable

Syntax HS_FDS_REMOTE_DB_CHARSET

Property Description

Default Value TRUE

Range of values {TRUE|FALSE}

Syntax HS_FDS_SUPPORT_STATISTICS= {TRUE|FALSE}

Property Description

Default Value TRUE

Initialization Parameter Description

Initialization Parameters D-13

If set to TRUE, the gateway will use array operations for insert, update, deletestatements containing binds against the remote data source. The array size isdetermined by the value of the HS_FDS_FETCH_ROWS init parameter.

If set to FALSE, the gateway will not use array operations for insert, update, and deletestatements. Instead, a single statement will be issued for every value.

Range of values {TRUE|FALSE}

Syntax HS_FDS_ARRAY_EXEC= {TRUE|FALSE}

Property Description

Initialization Parameter Description

D-14 Oracle Database Gateway for Teradata User's Guide

Index-1

Index

AALTER statement, B-1Arithmetic operators, B-2

BBYTE data type, A-1BYTEINT data type, A-1

CCase rules, 2-8Case studies, 3-1CHAR data type, A-1character sets

Heterogeneous Services, D-5COMMIT

restrictions, 2-10Commit point site, 2-10Comparison operators, B-2CONNECT BY clause, 2-11COPY command, 2-12CREATE statement, B-1Cursor loops

restrictions, 2-10

DData definition language, B-1Data dictionary

views, C-2Data type

BYTE, A-1BYTEINT, A-1CHAR, A-1conversion, 2-9DATE, A-1DECIMAL, A-1FLOAT, A-1INTEGER, A-1LONG, A-1LONG VARCHAR, A-1RAW, A-1SMALLINT, A-1TIME, A-1TIMESTAMP, A-1

VARBYTE, A-2VARCHAR, A-2VARCHAR2, A-2

DATE data type, A-1DDL statement, 2-11DECIMAL data type, A-1DELETE statement, 3-5, B-1, B-2demonstration build SQL script, 3-2Demonstration files, 3-2Demonstration tables, 3-2Demonstration tables build SQL script, 3-2describe cache high water mark

definition, D-4DROP statement, B-1

EError messages

error tracing, D-10Errors

ORA-02070, 2-10

Ffetch array size, with HS_FDS_FETCH_ROWS, D-11FLOAT data type, A-1

GGateway

case studies, 3-1data dictionary tables, C-1pass-through feature, 2-1supported functions, B-1supported SQL syntax, B-1

globalization supportHeterogeneous Services, D-4

GRANT statement, B-1Group functions, B-3

HHeterogeneous Services

defining maximum number of open cursors, D-6optimizing data transfer, D-6setting global name, D-4

Index-2

specifying cache high water mark, D-4tuning internal data buffering, D-6tuning LONG data transfer, D-5

Hexadecimal notation, 2-8HS_DB_NAME initialization parameter, D-4HS_DESCRIBE_CACHE_HWM initialization

parameter, D-4HS_FDS_CONNECT_INFO, D-8HS_FDS_DEFAULT_OWNER initialization

parameter, D-9HS_FDS_FETCH_ROWS parameter, D-11HS_FDS_PROC_IS_FUNC initialization

parameter, D-9HS_FDS_TRACE_LEVEL initialization

parameter, D-10enabling agent tracing, D-2

HS_FDS_TRANSACTION_LOG initializationparameter, D-10

HS_IDLE_TIMEOUT, D-11HS_KEEP_REMOTE_COLUMN_SIZE, D-12HS_LANGUAGE initialization parameter, D-4HS_LONG_PIECE_TRANSFER_SIZE initialization

parameter, D-5HS_NLS_LENGTH_SEMANTICS, D-11HS_OPEN_CURSORS initialization parameter, D-6HS_RPC_FETCH_REBLOCKING initialization

parameter, D-6HS_RPC_FETCH_SIZE initialization parameter, D-6HS_TIME_ZONE initialization parameter, D-7

IIFILE initialization parameter, D-8Initialization parameter file

customizing, D-1INSERT statement, 3-5, B-1, B-2INTEGER data type, A-1

KKnown restrictions, 2-10

LLocking, database, 2-9LONG data type, A-1LONG VARCHAR data type, A-1

NNVL function, 3-4

OObjects, naming rules, 2-7ORA-02070, 2-10

Pparameters

gateway initialization file

HS_FDS_FETCH_ROWS, D-11Passing commands to database, 2-11Pass-Through Feature, 3-5PL/SQL, 2-13

RRAW data type, A-1ROLLBACK

restrictions, 2-10ROWID, 2-11

Ssavepoint support, 2-10SELECT statement, 3-5, B-1, C-1SMALLINT data type, A-1String functions, B-3SUM function, 3-4

TTIME data type, A-1TIMESTAMP data type, A-1transactional capability, 2-10transactional integrity, 2-10TRUNCATE statement, B-1Two-phase commit, 2-10

UUPDATE statement, 3-5, B-2

VVARBYTE data type, A-2VARCHAR data type, A-2VARCHAR2 data type, A-2

WWHERE CURRENT OF clause, 2-11