B305 Fastexport

7/30/2019 B305 Fastexport

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Module 5: FastExport

After completing this module, you will be able to:

State FastExport capabilities.

Describe how sorted output is produced from a multiple-session SELECT.

Prepare a FastExport script.


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FastExport

Exports large volumes of formatted data from Teradata to a host file oruser-written application.

Takes advantage of multiple sessions.

Export from multiple tables.

Uses Support Environment.

Fully automated restart.

Uses one of the Loader slots.

Teradata

Database

Host

FastExport


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.BEGIN and .END EXPORT

.BEGIN EXPORT

SESSIONS max minTENACITY hours

SLEEP minutes

NOTIFY OFF | LOW | MEDIUM | HIGH ;

SESSIONS

Maximum, and optionally, minimum number of sessions the utility may use - defaults to 4 for UNIX

FastExport. The utility will log on two addit ionalSQL sessions: one for the Restart Log and one for the

SELECT.

TENACITY

Number of hours FastExport will try to establish a connection to the system; default is 4.

SLEEP

Number of minutes that FastExport will wait between logon attempts; default is 6.NOTIFY

Parameter for specifying the notify user exit option

The FastExport manual specifies in detail which events are associated with each level.

.END EXPORT;

Delimits a series of commands that define a single EXPORT action. Causes the utility to send the SELECT(s) to the Teradata Database.


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.EXPORT

.EXPORT OUTFILE fileid [ AXSMOD name [ ' in i t -s t r ing '] ] [ OUTMOD module_name ]

[ MODE RECORD | INDICATOR ]

[ BLOCKSIZE integer ]

[ FORMAT FASTLOAD | BINARY | TEXT | VARTEXT | UNFORMAT ]

[ OUTLIMIT record_count ]

[ MLSCRIPT fileid ] ;

MODE If RECORD, then indicator bytes for NULLs are not included in exported

data.

If INDICATOR, then indicator bytes for NULLs are included in exported data.

BLOCKSIZE Defines the maximum block size to be used in returning exported data.

Default (and maximum) is 63.5 KB.

FORMAT Record format of the export file on network-attached UNIX and Windows

platforms.

OUTLIMIT Defines the maximum number of records to be written to the output host

file.

MLSCRIPT FastExport generates a MultiLoad script that can be used later to load the


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A FastExport Script

.LOGTABLE RestartLog1_fxp;

.RUN FILE logon ;

.SET CityName TO 'Los Angeles';

.SET ZipCode TO 90666;

.BEGIN EXPORT SESSIONS 4 ;

.EXPORT OUTFILE custacct_data;

SELECT A.Account_Number

, C.Last_Name

, C.First_Name

, A.Balance_Current

FROM Accounts A INNER JOIN

Accounts_Customer AC INNER JOIN

Customer CON C.Customer_Number = AC.Customer_Number

ON A.Account_Number = AC.Account_Number

WHERE A.City = '&CityName'

AND A.Zip_Code = &ZipCode

ORDER BY 1 ;

.END EXPORT ;

.LOGOFF ;

Define Restart Log

Specify number of sessions

Destination file

Send request.

Terminate sessions

Via a SELECT, specify the

columns and rows to

export.


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The SELECT Request

Defines the data to be returned to the host, server, or client workstation.

The job may consist of multiple SELECT statements which will be executed

sequentially by FastExport.

Applies normal transaction locks (READ lock) which are fully automatic.

These locks are normally held by the utility until all response rows have

been moved to AMP spool, and then are released.

Supports the LOCKING FOR ACCESS modifier to request an access

lock.

Restrictions - you cannot use SELECT (in a FastExport job) with the

following:

Non-data tables (e.g. CURRENT_DATE, ...) Equality condition for a Primary Index or USI

WITH option to generate total or subtotal response rows.

The USING modifier to submit data parameters as a constraint to the

SELECT.


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Impact of Requesting Sorted Output

A special FastExport sort protocol is used to take advantage of multiplesessions. Each session transfers data a block at a time from multiple

AMPs.

This protocol includes the following steps:

The SELECT request is fully processed in the normal way using

DBC/SQL protocol.

At this point, response data is maintained in spool, sorted locally by

the AMPs.

Two further distributions between the AMPs (using the BYNET) are

required to complete the sort.

Sort notes:

Requesting sorted data adds additional work (overhead and time) to

Teradata.

If the exported rows are to be loaded back into a Teradata DB (e.g.,

MultiLoad), there probably is no need to sort the exported rows.


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The SORT Procedure

Response rows locally

sorted in SPOOL:

Horizontal Distribution:

Vertical Distribution:

ADAMS BATES BOYCE ADAMS

BOYCE DAVIS CHARLES DAVISFIELD KIEL HERBERT GEORGE

JONES NICHOLS POTTER HANCOCK

SMITH PETERS HERBERT

WILSON TIBBS MERCER

TOMS

BLOCK 1 BLOCK 2 BLOCK 3 BLOCK 4

ADAMS BOYCE FIELD HERBERT

ADAMS CHARLES GEORGE JONES

BATES DAVIS HANCOCK KIEL

BOYCE DAVIS HERBERT MERCER

BLOCK 5 BLOCK 6

NICHOLS TIBBS

PETERS TOMS

POTTER WILSONSMITH

AMP 1 AMP 2 AMP 3 AMP 4

ADAMS

ADAMS BATES BOYCE CHARLESDAVIS BOYCE

DAVIS FIELD GEORGE HANCOCK

HERBERT

HERBERT JONES KIEL MERCER

NICHOLS PETERS POTTER SMITH

TIBBS TOMS WILSON


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Multiple Exports in one FastExport Job

.LOGTABLE RestartLog2_fxp;.LOGON . . . . . . . . ;

.DISPLAY 'Exporting Cust_file - &SYSDATE4' TO FILE /dev/tty;

.BEGIN EXPORT;

.EXPORT OUTFILE Cust_file;

SELECT * FROM Customer;

.END EXPORT;

.DISPLAY 'Exporting Trans_file - &SYSDATE4' TO FILE /dev/tty;

.BEGIN EXPORT;

.EXPORT OUTFILE Trans_file;

SELECT * FROM Transactions;

.END EXPORT;

.LOGOFF ;

cust_trans.fxp

To execute: fexp < cust_trans.fxp > cust_trans.out

Exported data file: Cust_file Output to screen: Exporting Cust_file - 2003/02/28

Exported data file: Trans_file Output to screen: Exporting Trans_file - 2003/02/28


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Invoking FastExport

Network Attached Systems: fexp [PARAMETERS] < scr ip tname >outf i lename

Channel-Attached MVS Systems: // EXEC TDSFEXP FEXPPARM= [PARAMETERS]

Channel-Attached VM Systems: EXEC FASTEXPT [PARAMETERS]

Channel Network DescriptionParameter Parameter

BRIEF -b Reduces print output runtime to the least informationrequired to determine success or failure.

CHARSET=charsetname -c charsetname Specify a character set or its code. Examples are EBCDIC,ASCII, or Kanji sets.

ERRLOG=f i lename -e f i lename Alternate file specification for error messages; produces aduplicate record.

"fastexpor t command" -r 'fastexport cmd ' Signifies the start of a FastExport job; usually a RUN FILEcommand that specifies the script file.

MAXSESS=max sess ions -M max sessions Maximum number of FastExport sessions logged on.

MINSESS=min sess ions -N min sessions Minimum number of FastExport sessions logged on.

< scr ip tname Name of file that contains FastExport commands and SQLstatements.

> outf i lename Name of output file for FastExport messages.


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FastExport and Variable Input

Selection Controls

There are two techniques that can be used to provide variable input to

FastExport.

ACCEPT from a parameter file; only accept from a single record.

IMPORT from a data file; each import record is applied to every SELECT.

Read input variables from a host input data file described by the .LAYOUT

command.

Apply eachinput variable value to everySELECT in the exact order listed in

the FastExport script before reading the next.

Defines a host file as the source of the data values required for the SELECT

REQUEST.

Permits the use of a user-written INMOD routine to (optionally) read and

(always) process the input record before passing it to the utility.


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A FastExport Script with ACCEPT


.RUN FILE logon ;

.ACCEPT par_City, par_Zip FROM FILE parmfile1;


.EXPORT OUTFILE custacct_data;


, C.Last_Name

, C.First_Name

, A.Balance_Current





WHERE A.City = '&par_City'

AND A.Zip_Code = &par_Zip

ORDER BY 1 ;

.END EXPORT ;

.LOGOFF ;

'Los Angeles' 90066parmfile1

ACCEPT variables from input

record.

Reference accepted variables

with an &.

par_City par_Zip


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A FastExport Script with LAYOUT


.RUN FILE logon ;


.LAYOUT Record_Layout ;

.FIELD in_City 1 CHAR(20) ;

.FIELD in_Zip * CHAR(5);

.IMPORT INFILE city_zip_infile LAYOUT Record_Layout ;

.EXPORT OUTFILE cust_acct_outfile2 ;


, C.Last_Name

, C.First_Name

, A.Balance_Current





WHERE A.City = :in_City

AND A.Zip_Code = :in_Zip

ORDER BY 1 ;

.END EXPORT ;

.LOGOFF ;

Los Angeles 90066San Diego 90217

city_zip_infile

IMPORT fields from input

records.

Reference imported fields with

a :

in_City in_Zip


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.LAYOUT, .FIELD and .FILLER

.LAYOUT

Describes the layout of externally storedrecords used to supply values for SELECT.

Followed by .FIELD and .FILLER

commands.

.FIELD fieldname { startpos datadesc } || fieldexp [ NULLIF nullexpr ]

[ DROP {LEADING / TRAILING } { BLANKS / NULLS }[ [ AND ] {TRAILING / LEADING } { NULLS / BLANKS } ] ] ;

.FILLER [ fieldname ] startpos datadesc ;

.FIELD

Input fields supporting redefinition and concatenation.

Startpos identifies the start of a field relative to 1.

Fieldexpr specifies a concatenation of fields in the format: fn1 || fn2 [ || fn3 ]

The optionDROP LEADING / TRAILING BLANKS / NULLS is applicable only to

character datatypes, and is sent as a VARCHAR with a 2-byte length field.

.FILLER

Identifies data NOT to be sent to the Teradata database.

.LAYOUT layoutname

CONTINUEIF position = variable ;INDICATORS


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INMODs and OUTMODs

READ

FASTEXPORT

CALL

SELECT

OUTPUT

DATA

INMOD

OUTMOD

CALL

WRITE

INPUT

DATA

INMODs

Read input data values from a file.

Qualify SELECT requests.

Usually more applicable to an import utility such as MultiLoad.

OUTMODs

Process answer-set data.

Modify, discard, or record responses.

Usually more applicable to an export utility such as FastExport.


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OUTMOD Return Codes

1 Initial Entry Specifies the initial entry call that the FastExport utility makes before sending thefirst SELECT statement to the Teradata RDBMS.

There is only one initial entry call for a FastExport job. If the utility is in a restart mode, the utility

uses an entry code value of 5 or 6 to specify the first call after a Teradata RDBMS or client

system restart.

2 End of Response Entry Specifies the end of response call that the Fast Export utility makes

after receiving the last row of export data from the Teradata RDBMS.

3 Response Row Entry Specifies a response row call that the FastExport utility makes for each

row of export data from the Teradata RDBMS.

4 Checkpoint Entry Specifies a checkpoint call that the FastExport utility makes after

processing the last response row for each SELECT statement.

This call signifies that the OUTMOD routine should capture checkpoint data to support a restart

operation if the Teradata RDBMS or client system fails.

5 Teradata RDBMS Restart Entry Specifies the first call that resumes processing after a

Teradata RDBMS restart.

6 Client Restart Entry Specifies the first call that resumes processing after a client system

restart.

FastExport OUTMOD Return Codes


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Application Utility Checklist

Feature BTEQ FastLoad FastExport MultiLoad TPump

DDL Functions ALL LIMITED No

DML Functions ALL INSERT SELECT

Multiple DML Yes No Yes

Multiple Tables Yes No Yes

Multiple Sessions Yes Yes Yes

Protocol Used SQL FASTLOAD EXPORT

Conditional Expressions Yes No Yes

Arithmetic Calculations Yes No YesData Conversion Yes 1percolumn Yes

Error Files No Yes No

Error Limits No Yes No

User-written Routines No Yes Yes


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Summary

Best choice for exporting large amounts of data from the Teradata database

to a host file using multiple sessions.

Fully automatic restart capability.

Specialized processing of output data can be handled using an OUTMOD

routine.

Teradata accommodates not more than 15 LOAD applications at any onetime (FastLoad, MultiLoad, FastExport).


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Review Questions

Answer True or False.

1. True or False. FastExport requires the use of a PI or USI in the SELECTs.

2. True or False. The number of FastExport sessions (for a UNIX server) defaults to the number of

AMPs.

3. True or False. The maximum block size you can specify is 32K.

4. True or False. You can export from multiple tables with FastExport.

5. True or False. You can use multiple SELECTs in one FastExport job.

6. True or False. The default lock for a SELECT in a FastExport job is a table level ACCESS lock.


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Module 5: Review Question Answers

Answer True or False.

1. True orFalse. FastExport requires the use of a PI or USI in the SELECTs.

2. True orFalse. The number of FastExport sessions (for a UNIX server) defaults to the number of

AMPs. (The UNIX default is 4 sess ion s.)

3. True orFalse. The maximum block size you can specify is 32K. (It is 64 KB.)

4. Trueor False. You can export from multiple tables with FastExport.

5. Trueor False. You can use multiple SELECTs in one FastExport job.

6. True orFalse. The default lock for a SELECT in a FastExport job is a table level ACCESS lock.


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Lab Exercises

Lab Exercise 5-1

Purpose

In this lab, you will use FastExport to create an export file that contains one record for each

transaction. You will have to join columns from two different tables in order to create the export file.

What you need

Populated AU.Accounts and AU.Trans tables.

Tasks

1. Create a FastExport script that outputs to file data5_1. For each transaction in the AU.Trans table,

include the transaction_number, account_number, number, street, city, state and zip of the associated

account (AU.Accounts).

2. Run the script.

3. Test the result by using the UNIX ls -l command.


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Lab Exercises

Lab Exercise 5-2Purpose

In this lab, you will use FastExport to read input data from a data set / file or accepting input values as

a parameter, and export a report to another data set / file. In order to produce readable output, all

selected data should be converted to FIXED CHARACTER as outlined below:

What you need

Populated AU.Accounts table.

Tasks

This exercise involves the FastExport of 'EXCEPTION' data, a list of Accounts which either fall below aminimum Balance_Current or exceed a maximum value and are from the cities in the input data set.

The output file (report) mode should be RECORD and format should be TEXT.

1. Create an input file named data5_2 with 1 line of input: 'Los Angeles'

2. Prepare a FastExport script which does the following:

a. Treats this as a parameter file and ACCEPT from it. Treat this data as variable input for the

SELECT.

b. Uses the .SET command to initialize two variables: LoVal 500 and HiVal 9499

c. Includes a SELECT statement that projects ACCOUNT NUMBER, CITY, BALANCE CURRENT, and

a character string of either BELOW MIN or ABOVE MAX and sorts by Account_Number. Simply

display 'BELOW MIN' or 'ABOVE MAX' as a literal with the SELECT. Use CHAR to convert the

Account_Number from INTEGER to CHAR data.

d. Creates an output file named report5_2. Note: MODE RECORD and FORMAT TEXT3. Run the test and view the result using the UNIX morecommand.


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Lab Solutions for Lab 5-1

Lab Exercise 5-1

cat lab512.fxp

.LOGTABLE Restartlog512_fxp ;

.LOGON u4455/tljc30,tljc30 ;

.BEGIN EXPORT;

.EXPORT OUTFILE data5_1;

SELECT T.trans_number

,A.account_number

,A.number,A.street

,A.city

,A.state

,A.zip_code

FROM AU.Accounts A

INNER JOIN AU.Trans T

ON A.Account_number = T.Account_number;

.END EXPORT;

.LOGOFF;fexp < lab512.fxp

(alternative join syntax))

cat lab512a.fxp.LOGTABLE Restartlog512a_fxp ;

.LOGON u4455/tljc30,tljc30 ;

.BEGIN EXPORT;

.EXPORT OUTFILE data5_1;

SELECT T.trans_number

,A.account_number

,A.number,A.street

,A.city

,A.state

,A.zip_code

FROM AU.Accounts A

, AU.Trans T

WHERE A.Account_number = T.Account_number ;

.END EXPORT;

.LOGOFF;

fexp < lab512a.fxp


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Lab Solutions for Lab 5-2 (ACCEPT and CASE)

cat lab522a.fxp

.LOGTABLE Restartlog522a_fxp;

.LOGON u4455/tljc30,tljc30;

.SET LoVal TO 500;

.SET HiVal TO 9499;

.ACCEPT par_city FROM FILE data5_2;

.BEGIN EXPORT;

.EXPORT OUTFILE report522_a MODE RECORD FORMAT TEXT;

SELECT Account_Number (CHAR(10)),

City,

Balance_Current (CHAR(12)),

(CASE WHEN Balance_Current < &LoVal THEN 'Below MIN'

WHEN Balance_Current > &HiVal THEN 'Above MAX'

END)

FROM AU.Accounts

WHERE City = '&par_city'AND (Balance_Current < &LoVal OR

Balance_Current > &HiVal)

ORDER BY Account_Number ;

.END EXPORT;

.LOGOFF;

fexp < lab522a.fxp


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Lab Solutions for Lab 5-2 (ACCEPT and UNION)

cat lab522b.fxp

.LOGTABLE Restartlog522b_fxp;


.SET LoVal TO 500;

.SET HiVal TO 9499;

.ACCEPT par_city FROM FILE data5_2;

.BEGIN EXPORT;

.EXPORT OUTFILE report522_b MODE RECORD FORMAT TEXT;

SELECT Account_Number (CHAR(10)), City, Balance_Current (CHAR(12)),'Above MAX'

FROM AU.Accounts

WHERE City = '&par_city'

AND Balance_Current > &HiVal

UNION

SELECT Account_Number (CHAR(10)), City, Balance_Current (CHAR(12)),

'Below MIN'

FROM AU.Accounts

WHERE City = '&par_city'

AND Balance_Current < &LoVal

ORDER BY 1;

.END EXPORT;

.LOGOFF;

fexp < lab522b.fxp


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Lab Solutions for Lab 5-2 (.IMPORT)

cat lab522c.fxp

.LOGTABLE Restartlog522c_fxp;


.SET LoVal TO 500;

.SET HiVal TO 9499;

.BEGIN EXPORT;

.LAYOUT Record_Layout;

.FIELD in_city * CHAR(15);

.IMPORT INFILE data5_2c FORMAT TEXT LAYOUT Record_Layout ;

.EXPORT OUTFILE report522_c MODE RECORD FORMAT TEXT;

SELECT Account_Number (CHAR(10)),

City,

Balance_Current (CHAR(12)),

(CASE WHEN Balance_Current < &LoVal THEN 'Below MIN'

WHEN Balance_Current > &HiVal THEN 'Above MAX'END)

FROM AU.Accounts

WHERE City = :par_city

AND (Balance_Current < &LoVal OR Balance_Current > &HiVal)

ORDER BY Account_Number ;

.END EXPORT;

.LOGOFF;

f l b522 f

B305 Fastexport

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