QUERY TUNING – As the Oracle Developer- Dont be a target for slow performance.

QUERY TUNING –

As the Oracle Developer-Don’t be a target for slow performance

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Agenda(1)Basic trouble spots for SQL queries(2)Tools used for identifying trouble spots – EXPLAIN PLAN

(3)Tuning of SQL queries(4)Real life examples of SQL queries(5)Tuning of PL-SQL(6)Real life examples of PL-SQL(7)Discussion of Real Life Examples.

The goal is to be able to identify basic SQL trouble spots , to understand The explain plan tool for identifying trouble spots, and to go through real Life examples of tuning SQL queries and PL-SQL code.

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(1)(1)Basic trouble spots for sql queriesBasic trouble spots for sql queries

Creating the Oracle Table:

The basics of an index:Indexes help you to retrieve your data quickly –They do a “binary” search on your Oracle tables.

To choose what columns to indexChoose a column, or combination of columnsWhich have the most unique values. Do not chooseA column, or columns which have mostly the same Values. If a column has mostly the same values, An index will hurt performance. Know how the Table is going to be used, and what data you areGoing after in the table. For example, for an employee table, you want the index on socialSecurity number (a unique value). BUT, if you were going to search on name, you wouldWant an index specifically on the NAME column.

Querying the Oracle table:Set up your query in such a way that OracleWill use the index of the columns that youAre querying.

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(1)(1)Basic trouble spots for sql queriesBasic trouble spots for sql queries

When processing a query, Oracle ranks the indexes, and determines which one to use. When setting a column equal to a literal string, this is the highest ranking,And chances are that the index to that column will be used. The next highest ranking is greater than or less than (>, <)A literal.

There are several factors in THE WHERE CLAUSE of a query that can causeAn index not to be used:

1. Using a function on the left side. Substr(plant_code,1,5) = ‘AP05A’, Since there is a function around the column,

the index will not be used. This includes Oracle functions such as to_char, to_number, ltrim, rtrim, instr, trunc, rpad , lpad

2. Comparing incompatible data. Employee_num = ‘1’

There will be an implicit to_char conversion used. plant_code = 1234

There will be an implicit to_num conversion used.3. Using is null and is not null .

Select * FROM s_emp WHERETitle is null;

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Basic trouble spots for sql queries Basic trouble spots for sql queries (continued)(continued)

(3) Using is null and is not null. (Continued)Select * FROM s_emp WHERETitle is not null;

Since the column title has null values, and is compared to a null value, the index can not be used.

(4) Adding additional criteria in the where clause for a column name that is of a different index

Select * from s_empwhere title= ‘Manager’and Department = 500 Column title and department have

separate indexes on these columns.

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Solutions toSolutions toBasic trouble spots for sql queriesBasic trouble spots for sql queries

Problem:Problem:1. Using a function on the left side.

Select * from s_empWhere substr(title,1,3) = ‘Man’;

Select * from s_empWhere trunc(hire_date) = trunc(sysdate);

Solution: Use likeSelect * from s_empWhere title like ‘Man%’;

Use >, <Select * from s_empwhere hire_date >= sysdateand hire_date < sysdate + 1;

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Solutions toSolutions toBasic trouble spots for sql queriesBasic trouble spots for sql queries(continued)(continued)

Problem:Problem:2. Comparing incompatible data types.

Select * from s_empWhere employee_number = ‘3’;

Select * from s_empWhere hire_date = ’12-jan-01’;

Solution: Select * from s_emp

Where employee_number = 3;

Select * from s_empWhere hire_date = to_date(’12-jan-01’);

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Problem:Problem:3. Using null and not null

Select * from s_empWhere title is not null;

Select * from s_empWhere title is null;

Solution: Select * from s_emp where title >= ‘ ‘;

Use an Oracle hint select /*+ index (s_emp) */ Oracle hints are always enclosed in /*+ */ and must come

from s_emp directly after the select clause. The index hint causes indexes to be

where title is null; used.

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Problem:Problem:4. Adding additional criteria in the where clause for a column name that is of a different index

Select * from s_empwhere title= ‘Manager’and salary = 100000;

Solution:Use an Oracle hint select /*+ index (s_emp) */ Oracle hints are always enclosed in /*+ */ and must come

from s_emp directly after the select clause. The index hint causes indexes

where title= ‘Manager’ to be used. S_EMP is the Oracle table

and salary = 100000;

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(2) Explain plan:Explain plan is a utility that will show you what indexes are being used In the table AND what type of scan is being done on the table(full table scan, index range scan etc..)

(1)Make sure you have the plan_table desc plan_table.

(2) If you do not – run the explain plan utility

go to the /usr/oracle/product/8.1.6.64/rdbms/admin

or/$oracle_home/rdbms/admin

(3) Run utlxplan.sql in sql (I.e. @ utlxplan.sql )

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Do an explain plan on your statement such as:DELETE FROM plan_table WHERE statement_id = 'TEST';

EXPLAIN PLAN SET statement_id = 'TEST' FOR {query};

Put this in an sql file called explain.sqlThen do @explain from SQL

Set up a query to go after the plan_table:select lpad(' ',2*level) || operation || ' ' || Options || ' ' || object_name execution_pathfrom plan_tablewhere statement_id = 'TEST‘connect by prior id = parent_id and statement_id = 'TEST‘start with ID=1;

Put this in an sql file called @explain2.sqlThen do @explain2 from SQL

(2) Explain plan: (continued)

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(2) Explain plan: (continued)Sample result from explain plan: -- explain2.sql

Example 1:EXECUTION_PATH-------------------------------------------------------------------------------- TABLE ACCESS BY INDEX ROWID VEHICLE INDEX RANGE SCAN FKI_VEHICLE_1 SORT AGGREGATE TABLE ACCESS BY INDEX ROWID VEHICLE INDEX RANGE SCAN FKI_VEHICLE_1

EXECUTION_PATH-------------------------------------------------------------------------------- SORT AGGREGATE TABLE ACCESS FULL VEHICLE SORT AGGREGATE SORT AGGREGATE TABLE ACCESS FULL VEHICLE --> NOTICE A FULL TABLE SCAN

• LOOK for FULL TABLE SCAN and attempt to eliminate it.

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(3) Tuning of SQL queries1. Find out what indexes are on the tables2. Run explain plan3. Make sure most restrictive indexes are being used by avoiding SQL trouble spots.4. Make sure most restrictive indexes are being used by using Oracle hints. 5. For multi-table joins, join everything that can be joined together.6. Use unions instead of outer joins7. Use “exists” subquery if only selecting items from 1 table.

The query:select count(*) from vehicleWhere assembly_location_code = 'AP24A'and production_date = '06-apr-01';

This will select vin (vehicle ID , Market information, and other information about a vehicle

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(3) Tuning of SQL queries (cont)(1) Find out what indexes are on this table--- CRUCIAL

Select column_name, index_name from all_ind_columnsWhere table_name =‘VEHICLE’;

Samle output:Column_name Index nameAssembly_location_code FKI_VEHICLE_1Production_date FK_PRODUCTION_DATEVehicle id FKI_PRODUCTION_DATEVehicle_id PK_VEHICLE

(2) Run an explain plan on this queryIn explain.sql

DELETE FROM plan_table WHERE statement_id = 'TEST';

EXPLAIN PLAN SET statement_id = 'TEST' FORselect count(*) from vehiclewhereassembly_location_code = 'AP24A'and production_date = '06-apr-01'; --> Notice that an index will still not be used

@[email protected]

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(3) Tuning of SQL queries (cont)Results of explain plan:

EXECUTION_PATH-------------------------------------------------------------------------------- SORT AGGREGATE TABLE ACCESS FULL VEHICLE SORT AGGREGATE SORT AGGREGATE TABLE ACCESS FULL VEHICLE Notice that the full table scan is performed

(3) Enable indexes to be used – ELIMINATE “TABLE ACCESS FULL “A. TRY AN ORACLE HINT. Index(vehicle) means that Oracle will choose to use an index on the table name

vehicle.

Explain.sql looks like:DELETE FROM plan_table WHERE statement_id = 'TEST';

EXPLAIN PLAN SET statement_id = 'TEST' FORselect /*+ index(vehicle) */ count(*) from vehiclewhereassembly_location_code = 'AP24A'and production_date = '06-apr-01'; --> Notice an index will be used now

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(3) Tuning of SQL queries (cont)(3) Enable indexes to be used – ELIMINATE “TABLE ACCESS FULL “ (continued)

Results of explain plan:

EXECUTION_PATH-------------------------------------------------------------------------------- TABLE ACCESS BY INDEX ROWID VEHICLE INDEX RANGE SCAN FKI_PRODUCTION_DATE SORT AGGREGATE TABLE ACCESS BY INDEX ROWID VEHICLE INDEX RANGE SCAN FKI_PRODUCTION_DATE

(4) Force the use of the most restrictive index FKI_VEHICLE_1A. TRY AN ORACLE HINT. Index(vehicle FKI_VEHICLE_1) means that Oracle will use the FKI_VEHICLE index on the table name vehicle.

Explain.sql looks like:DELETE FROM plan_table WHERE statement_id = 'TEST';

EXPLAIN PLAN SET statement_id = 'TEST' FORselect /*+ index(vehicle FKI_VEHICLE_1) */ count(*) from vehiclewhereassembly_location_code = 'AP24A'and production_date = '06-apr-01'; --> Notice the FKI_VEHICLE_1 hint will be used now.

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Results of explain plan:

EXECUTION_PATH--------------------------------------------------------------------------------TABLE ACCESS BY INDEX ROWID VEHICLEINDEX RANGE SCAN FKI_VEHICLE_1SORT AGGREGATETABLE ACCESS BY INDEX ROWID VEHICLEINDEX RANGE SCAN FKI_VEHICLE_1 Notice that the most restrictive index is used now.

Results of query time differences:-------------------> This does not use an indexselect count(*) from vehiclewhereassembly_location_code = 'AP24A'and production_date = '06-apr-01'; SQL> @tt COUNT(*)---------- 787Elapsed: 00:00:10.00 ------> Notice it is 10 seconds.

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--------------------> This is where the query does use an indexSQL> get tt.sql 1 select /*+ index (vehicle FKI_VEHICLE_1) */ count(*) from vehicle 2 where 3 assembly_location_code = 'AP24A' 4* and production_date = '06-apr-01'; 5SQL> set timing onSQL> @tt

COUNT(*)---------- 787

Elapsed: 00:00:00.88 ------> Notice it is less than 1 secondUSE THE MOST SELECTIVE INDEX that will return the fewest records.

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CONTINUING ON about INDEXES:

Look at the following query: (vehicle material cost summarizesThe cost of the vehicles) The vehicle table is information about the vehicle)

select /*+ index(t1 PK_VEHICLE_MATERIAL_COST) */ count(*) from vehicle_material_cost t1 where vehicle_id in (select /*+ index(t2 fki_vehicle_1) -- SAME INDEX AS BEFORE vehicle_id from vehicle t2 where t1.vehicle_id =t2.vehicle_id and assembly_location_code = 'G9W1A' and production_date = '22-apr-03') and vehicle_id > 0 and currency_code > ' ';

This query takes a while because the proper index is NOT used on the vehicle table:

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SQL> list 1 select column_name, index_name from all_ind_columns 2 where index_name = 'I_VEHICLE_5' 3* and table_name = 'VEHICLE'SQL> /

COLUMN_NAME--------------------------------------------------------------------------------INDEX_NAME------------------------------PRODUCTION_DATEI_VEHICLE_5

ASSEMBLY_LOCATION_CODEI_VEHICLE_5

WE NEED AN INDEX that uses BOTH production dateAnd ASSEMBLY_LOCATION_CODE:

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SQL> set timing onSQL> list 1 select /*+ index(t1 PK_VEHICLE_MATERIAL_COST) */ count(*) from vehicle_ma1 2 where vehicle_id in 3 (select /*+ index(t2 I_VEHICLE_5) */ vehicle_id 4 from vehicle t2 where 5 t1.vehicle_id =t2.vehicle_id 6 and assembly_location_code = 'G9W1A' 7 and production_date = '22-apr-03' 8 and rownum <= 1) 9 and vehicle_id > 0 10* and currency_code > ' 'SQL> /

COUNT(*)---------- 1803

Elapsed: 00:00:00.46

Now, if we use the proper index (I_VEHICLE_5) the queryWill be FAST

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(3) Tuning of SQL queries (cont)MUTI-Table queries

1) Make sure everything that can be joined is joined (for 3 or more tables) Instead of:

select * from t1, t2, t3where t1.emp_id = t2.emp_idand t2.emp_id = t3.emp_id

add:select * from t1, t2, t3where t1.emp_id = t2.emp_idand t2.emp_id = t3.emp_idand t1.emp_id = t3.temp_id;

2) Make sure smaller table is first in the from clause3) Use unions instead of outer-joins. 4) Use not exists instead of not in. USE a correlated

sub-query.

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(4) Tuning of SQL queries Real life exampleTHE QUERYSELECT mfal_vl_code, mod_yr, effective_out_date, mfal_gvw_mkt_der_code, mfal_market_code, mfal_series_trim_code, mfal_bs_code,mfal_eng_code, mfal_trans_code, mfal_drv_code, mfal_feature_code, sum(decode(ucc_qtrly_volume, 0, 0, (weight/ucc_qtrly_volume))) rate from cpat_gvp_extract_main where substr(mfal_feature_code, 1, 1) not in ( '1', '2', '3', '4', '5', '6', '7', '8', '9', '0', 'P', 'X' ) and substr( mfal_feature_code, 1, 3) not in ( 'EN ', 'TR ', 'DR ', 'MD ', 'SE ', 'BS ', 'CA ', 'VS ', 'AAA', 'AAG', 'AAF', 'AAH' ) and substr( mfal_feature_code, 1, 2) not in ( 'WA', 'WS' ) and mfal_feat_family_code not like 'PTR%' and ( mfal_series_trim_code like 'AAA%' or mfal_series_trim_code like 'VS %' ) and ( substr( mfal_feature_code, 4, 1) not in ( '1', '2', '3', '4', '5', '6', '7', '8', '9') or substr( mfal_feature_code, 5, 1) not in ( '1', '2', '3', '4', '5', '6', '7', '8', '9') ) Group by mfal_vl_code, mod_yr, effective_out_date, mfal_gvw_mkt_der_code, mfal_market_code, mfal_series_trim_code, mfal_bs_code, mfal_eng_code, mfal_trans_code, mfal_drv_code, mfal_feature_code ;

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(4) Tuning of SQL queries Real life example (continued)1) The indexes are:Select column_name, index_name from all_ind_columnsWhere table_name =‘CPAT_GVP_EXTRACT_MAIN ’;

Samle output:Column_name Index nameMFAL_FEATURE_CODE CGEM_CFC_IND_XMFAL_VL_CODE CGEM_VL_IND_XMOD_YR CGEM_VL_IND_XMFAL_FEAT_FAMILY_CODE CGEM_VL_IND_XMFAL_VL_CODE CGEM_VL_IND_XMOD_YR CGEM_VL_IND_X

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(4) Tuning of SQL queries Real life example (continued)

The tuned query:set timing onSELECT /*+ index (cpat_gvp_extract_main CGEM_CFC_IND_X) */ -> Notice index hint mod_yr, effective_out_date, mfal_gvw_mkt_der_code, mfal_market_code, mfal_series_trim_code, mfal_bs_code,mfal_eng_code, mfal_trans_code, mfal_drv_code, mfal_feature_code, sum(decode(ucc_qtrly_volume, 0, 0, (weight/ucc_qtrly_volume))) rate from cpat_gvp_extract_main where mfal_feature_code not like '1%' and mfal_feature_code not like '2%' and mfal_feature_code not like '3%' and mfal_feature_code not like '4%' and mfal_feature_code not like '5%‘ Notice the use of like instead of substr. and mfal_feature_code not like '6%' and mfal_feature_code not like '7%' and mfal_feature_code not like '8%' and mfal_Feature_code not like '9%' and mfal_feature_code not like '0%' and mfal_feature_code not like 'P%' and mfal_feature_code not like 'X%'

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and mfal_feature_code not like 'EN%' and mfal_feature_code not like 'TR%' and mfal_Feature_code not like 'DR%' and mfal_feature_code not like 'MD%' and mfal_feature_code not like 'SE%' and mfal_feature_code not like 'BS%' and mfal_Feature_code not like 'CA%' and mfal_feature_code not like 'VS%' and mfal_Feature_code not like 'AAA%' and mfal_feature_code not like 'AAG%' and mfal_feature_code not like 'AAF%' and mfal_Feature_code not like 'AAH%' and mfal_feature_code not like 'WA%' and mfal_feature_code not like 'WS%' and mfal_feat_family_code not like 'PTR%' and (( mfal_series_trim_code like 'AAA%' or mfal_series_trim_code like 'VS %' ) and (mfal_feature_code not like '___1%' and mfal_feature_code not like '___2%' and mfal_feature_code not like '___3%' and mfal_feature_code not like '___4%' and mfal_feature_code not like '___5%' and mfal_feature_code not like '___6%' and mfal_feature_code not like '___7%' and mfal_feature_code not like '___8%' and mfal_feature_code not like '___9%')


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OR ( mfal_feature_code not like '___1%' and mfal_feature_code not like '____2%' and mfal_feature_code not like '____3%' and mfal_feature_code not like '____4%' and mfal_feature_code not like '____5%' and mfal_feature_code not like '____6%' and mfal_feature_code not like '____7%' and mfal_feature_code not like '____8%' and mfal_feature_code not like '____9%'))Group by mfal_vl_code, mod_yr, effective_out_date, mfal_gvw_mkt_der_code, mfal_market_code, mfal_series_trim_code, mfal_bs_code, mfal_eng_code, mfal_trans_code, mfal_drv_code, mfal_feature_code ;

Time improved from 4 hours to 30 minutes.


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Multi-table join example:

SELECT raw_part_number, price_type_code, IB.BOM_RECNO RECNO,vV.VEHICLE_ID,IB.PART_ID,IB.PARENT_PART_ID, BOM_LEVEL PART_LEVEL,IB.PART_USING_LOCATION_CODE,IB.SHIP_FROM_LOCATION_CODE, LPAD(' ',2*(BOM_LEVEL-1)) || PART_PREFIX || '-' ||PART_BASE || '-' || PART_SUFFIX || '-' || PART_CONTROL_NUMBER INDENTED_PART_NUMBER, IB.FORD_AFFILIATE_CODE,IB.MISSING_STRUCTURE_CODE,IB.BOM_ID VIN, IB.EFFECTIVE_DATE PRODUCTION_DATE,IB.CPSC_CODE,IB.TOP_CPSC_CODE,PART_BASE, PART_PREFIX,PART_SUFFIX,PART_CONTROL_NUMBER,ULP.PART_DESCRIPTION, ULP.PART_TYPE,PI.COMMODITY_CODE,L.LOCATION_NAME SUPPLIER_NAME, ULP.PART_UNIT_OF_MEASURE,IB.USAGE_QUANTITY,IB.WEIGHT, IB.NOTES,IB.ALTERNATE_PART_PERCENT, IB.NEXT_AVAIL_BURDEN_DEPT, IB.PERCENT_OF_BUSINESS,IB.RAW_PERCENT_OF_BUSINESS, ULP.PSEUDO_ALTERNATE_PART_CODE, ULP.WAREHOUSE_PART_FLAG,ULP.BURDEN_DEPARTMENT_NUMBER, IB.SUPPLIER_TYPE, IB.MANUFACTURING_PLANT_CODE, PO.PRICE PO_PRICE, PO.CURRENCY_CODE PO_CURRENCY_CODE, PO.PO_EFFECTIVE_DATE, PO.CHARGE_FROM_DATE PO_CHARGE_FROM_DATE, PO.PURCHASING_MANAGER_CODE PO_PURCHASING_MANAGER_CODE, PO.PURCHASING_MANAGER_CDSID PO_PURCHASING_MANAGER_CDSID, PO.BUYER_CODE PO_BUYER_CODE, PO.BUYER_CDSID PO_BUYER_CDSID, PO.RETURN_CODE PO_RETURN_CODE, PO.PRICING_RULE PO_PRICING_RULE,PO.PRICING_SUBRULE PO_PRICING_SUBRULE, ICS.TRANSFER_PRICE_EFFECTIVE_DATE, ICS.TRANSFER_PRICE ICS_PRICE,ICS.CURRENCY_CODE ICS_CURRENCY_CODE, ICS.RETURN_CODE ICS_RETURN_CODE, IB.ROLLED_UP_COST ROLLED_UP_PRICE,

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IB.PRICE_USED BOM_PRICE, IB.PRICE_SYSTEM_USED FROM INDENTED_BOM IB, VEHICLE_VIN VV, PART_INFO PI, USING_LOCATION_PART ULP, LOCATION L, PURCHASE_ORDER PO, INTERCOMPANY_SETTLEMENT ICS WHERE IB.PART_ID=PI.PART_ID AND IB.PART_ID=ULP.PART_ID AND IB.PART_USING_LOCATION_CODE=ULP.PART_USING_LOCATION_CODE AND IB.SHIP_FROM_LOCATION_CODE=L.LOCATION_CODE AND IB.PART_ID=PO.PART_ID(+) AND IB.PART_USING_LOCATION_CODE=PO.PART_USING_LOCATION_CODE(+) AND IB.SHIP_FROM_LOCATION_CODE=PO.SHIP_FROM_LOCATION_CODE(+) AND IB.PO_EFFECTIVE_DATE=PO.PO_EFFECTIVE_DATE(+) AND IB.PO_CHARGE_FROM_DATE=PO.CHARGE_FROM_DATE(+) AND IB.PART_ID=ICS.PART_ID(+) AND IB.PART_USING_LOCATION_CODE=ICS.PART_USING_LOCATION_CODE(+) AND IB.SHIP_FROM_LOCATION_CODE=ICS.SHIP_FROM_LOCATION_CODE(+) AND IB.TRANSFER_PRICE_EFFECTIVE_DATE=ICS.TRANSFER_PRICE_EFFECTIVE_DATE(+) AND IB.BOM_ID=vV.VIN(+) ;

Multi-table join example (continued):

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EXECUTION_PATH-------------------------------------------------------------------------------- TABLE ACCESS FULL LOCATION HASH JOIN OUTER HASH JOIN OUTER HASH JOIN TABLE ACCESS FULL PART_INFO HASH JOIN OUTER HASH JOIN TABLE ACCESS FULL USING_LOCATION_PART TABLE ACCESS FULL INDENTED_BOM TABLE ACCESS FULL VEHICLE_VIN

TABLE ACCESS FULL INTERCOMPANY_SETTLEMENT NOTICE FULL TABLE SCANS

EXECUTION_PATH-------------------------------------------------------------------------------- TABLE ACCESS FULL PURCHASE_ORDER HASH JOIN TABLE ACCESS FULL LOCATION HASH JOIN OUTER HASH JOIN OUTER HASH JOIN TABLE ACCESS FULL PART_INFO HASH JOIN OUTER HASH JOIN TABLE ACCESS FULL USING_LOCATION_PART TABLE ACCESS FULL INDENTED_BOM

EXECUTION_PATH-------------------------------------------------------------------------------- TABLE ACCESS FULL VEHICLE_VIN TABLE ACCESS FULL INTERCOMPANY_SETTLEMENT TABLE ACCESS FULL PURCHASE_ORDER


RESULTS OF Explain plan:

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Modify multi table join in the where clause:

WHERE IB.PART_ID=PI.PART_ID AND

ulp.part_id=pi.part_id add this part to the where clauseand IB.PART_ID=ULP.PART_ID AND IB.PART_USING_LOCATION_CODE=ULP.PART_USING_LOCATION_CODE AND IB.SHIP_FROM_LOCATION_CODE=L.LOCATION_CODE AND IB.PART_ID=PO.PART_ID(+) AND IB.PART_USING_LOCATION_CODE=PO.PART_USING_LOCATION_CODE(+) AND IB.SHIP_FROM_LOCATION_CODE=PO.SHIP_FROM_LOCATION_CODE(+) AND IB.PO_EFFECTIVE_DATE=PO.PO_EFFECTIVE_DATE(+) AND IB.PO_CHARGE_FROM_DATE=PO.CHARGE_FROM_DATE(+) AND IB.PART_ID=ICS.PART_ID(+) AND IB.PART_USING_LOCATION_CODE=ICS.PART_USING_LOCATION_CODE(+) AND IB.SHIP_FROM_LOCATION_CODE=ICS.SHIP_FROM_LOCATION_CODE(+) AND IB.TRANSFER_PRICE_EFFECTIVE_DATE=ICS.TRANSFER_PRICE_EFFECTIVE_DATE(+) AND IB.BOM_ID=vV.VIN(+)

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RESULTS OF Explain plan:

EXECUTION_PATH-------------------------------------------------------------------------------- NESTED LOOPS NESTED LOOPS OUTER NESTED LOOPS OUTER NESTED LOOPS HASH JOIN TABLE ACCESS FULL PART_INFO TABLE ACCESS FULL INDENTED_BOM TABLE ACCESS BY INDEX ROWID LOCATION INDEX UNIQUE SCAN PK_LOCATION TABLE ACCESS BY INDEX ROWID INTERCOMPANY_SETTLEMENT INDEX UNIQUE SCAN PK_INTERCOMPANY_SETTLEMENT

EXECUTION_PATH-------------------------------------------------------------------------------- TABLE ACCESS BY INDEX ROWID PURCHASE_ORDER INDEX UNIQUE SCAN PK_PURCHASE_ORDER

TABLE ACCESS BY INDEX ROWID USING_LOCATION_PART NOTICE INDEXES USED INDEX UNIQUE SCAN PK_USING_LOCATION_PART TABLE ACCESS BY INDEX ROWID VEHICLE_VIN INDEX RANGE SCAN UK_VEHICLE_VIN NESTED LOOPS OUTER NESTED LOOPS NESTED LOOPS OUTER NESTED LOOPS OUTER NESTED LOOPS

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EXECUTION_PATH-------------------------------------------------------------------------------- HASH JOIN TABLE ACCESS FULL PART_INFO TABLE ACCESS FULL INDENTED_BOM TABLE ACCESS BY INDEX ROWID LOCATION INDEX UNIQUE SCAN PK_LOCATION TABLE ACCESS BY INDEX ROWID INTERCOMPANY_SETTLEMENT INDEX UNIQUE SCAN PK_INTERCOMPANY_SETTLEMENT TABLE ACCESS BY INDEX ROWID PURCHASE_ORDER INDEX UNIQUE SCAN PK_PURCHASE_ORDER TABLE ACCESS BY INDEX ROWID USING_LOCATION_PART NOTICE INDEXES USED

INDEX UNIQUE SCAN PK_USING_LOCATION_PART

EXECUTION_PATH-------------------------------------------------------------------------------- TABLE ACCESS BY INDEX ROWID VEHICLE_VIN INDEX RANGE SCAN UK_VEHICLE_VIN


RESULTS OF Explain plan continued:

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Real life example (continued)

Suppose you have to select all of the employee’s that areNot account representatives

Table 1: Table2: S_emp s_account_rep Soc_number soc_number last_name last_name first_name first_name salary region

This query is slower: select soc_number from s_emp minus select soc_number from s_account_rep because the minus has to select distinct values from both tables.

This query is a little faster select soc_number from s_emp where soc_number not in (select soc_number from

s_account_rep)Faster, but still not as fast because we are not joining And are not using indexes.

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Real life example (continued)

Suppose you have to select all of the employee’s that areNot account representatives

Table 1: Table2: S_emp s_account_rep Soc_number soc_number last_name last_name first_name first_name salary region

This query is fast:

Select /*+ index(t1) */ soc_number from s_emp t1Where Not exists(select /*+ index(t1) index(t2) */ * from s_account_rep t2 whereT1.soc_number = t2.soc_number);

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(5) Tuning of PL SQL code:Everything said about tuning SQL queries holds with the addition of (1) Using explicit instead of implicit cursors(2) Eliminating cursors where ever possible(3) Using rowid to update (4) Use truncate instead of delete IF you want to delete ALL of the

data from the table.(5) Use PL/SQL tables for iterations.(6) Eliminate excessive use of execute immediate (Oracle 8i).

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(5) Tuning of PL SQL code (continued)(1) Using explicit instead of implicit cursors

Implicit cursors always take longer than explicit cursors because they are doing an extra to make sure that there is no more data.

Instead of:select count(*) into tot from s_emp

where emp_id = v_emp_id;

Declare a cursor for the count: Or if just checking for existence cursor cnt_emp_cur(v_emp_id number) is cursor cnt_emp_cur(v_emp_id number) is

select count(*) emp_total from s_emp select emp_id from s_emp where emp_id= v_emp_idwhere emp_id = v_emp_id; and rownum = 1;

cnt_emp_rec cnt_emp%rowtype;

And then do the fetch from this cursor:…open cnt_emp(v_emp_id);fetch cnt_emp into cnt_emp_rec;…close cnt_emp;

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(5) Tuning of PL SQL code (continued)(2) Eliminating cursors where ever possible

Instead of :

INSERT INTO TEMP_PARTSOURCE_DIFFER(PART_ID,PART_USING_LOCATION_CODE,SHIP_FROM_LOCATION_CODE,PART_SOURCE_EFFECTIVE_DATE)

(SELECT A.PART_ID, A.PART_USING_LOCATION_CODE, A.SHIP_FROM_LOCATION_CODE,A.PART_SOURCE_EFFECTIVE_DATE

FROM PART_SOURCE AWHERE A.PART_USING_LOCATION_CODE=V_PLANTAND A.PART_ID =V_PART_IDAND A.PERCENT_OF_BUSINESS>0AND A.PART_SOURCE_EFFECTIVE_DATE=

(SELECT MAX(PART_SOURCE_EFFECTIVE_DATE) FROM PART_SOURCE B

WHERE B.PART_ID=A.PART_ID AND B.PART_USING_LOCATION_CODE=A.PART_USING_LOCATION_CODE AND B.SHIP_FROM_LOCATION_CODE=A.SHIP_FROM_LOCATION_CODE))

MINUS (SELECT PART_ID, PART_USING_LOCATION_CODE,

SHIP_FROM_LOCATION_CODE,PART_SOURCE_EFFECTIVE_DATE FROM TEMP_PARTSOURCE

WHERE PART_ID=V_PART_ID AND PART_USING_LOCATION_CODE=V_PLANT);

And then having a cursor to go off the temp_partsource_differ tableCURSOR CS_TEMP_PART_SOURCEDIFFER ISSELECT PART_ID,

PART_USING_LOCATION_CODE,SHIP_FROM_LOCATION_CODE,APP_PEND_INDICATOR

FROM TEMP_PARTSOURCE_DIFFER;

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(5) Tuning of PL SQL code (continued)(2) Eliminating cursors where ever possible (continued)

Have the cursor go directly off of this query:Cursor temp_partsource_differ (v_plant varchar2, v_part_id number)SELECT A.PART_ID, A.PART_USING_LOCATION_CODE,

A.SHIP_FROM_LOCATION_CODE,A.PART_SOURCE_EFFECTIVE_DATE FROM PART_SOURCE A

WHERE A.PART_USING_LOCATION_CODE=V_PLANTAND A.PART_ID =V_PART_IDAND A.PERCENT_OF_BUSINESS>0AND A.PART_SOURCE_EFFECTIVE_DATE=

(SELECT MAX(PART_SOURCE_EFFECTIVE_DATE) FROM PART_SOURCE B

WHERE B.PART_ID=A.PART_ID AND B.PART_USING_LOCATION_CODE=A.PART_USING_LOCATION_CODE AND B.SHIP_FROM_LOCATION_CODE=A.SHIP_FROM_LOCATION_CODE)

MINUS (SELECT PART_ID, PART_USING_LOCATION_CODE,

SHIP_FROM_LOCATION_CODE,PART_SOURCE_EFFECTIVE_DATE FROM TEMP_PARTSOURCE

WHERE PART_ID=V_PART_ID AND PART_USING_LOCATION_CODE=V_PLANT);

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The PL/SQL code

set serveroutput on size 1000000set linesize 500set pagesize 0set feedback offset termout off spool check_vinbom_result_052201.txtdeclare v_exchange_date DATE:='01-MAY-2001';v_start_date DATE:='16-MAY-2001';v_end_date DATE:='22-MAY-2001';v_plant VARCHAR2(5);v_curr_start_date DATE;v_vehicle VARCHAR2(3);v_bulk_material NUMBER;v_st_line_bom NUMBER;v_all_parts_bom NUMBER;v_vin NUMBER;v_vin1 NUMBER:=0;v_vin2 NUMBER:=0;v_count NUMBER;v_bulk_eff_date DATE;v_vin_all_perc_diff NUMBER;v_vin_st_perc_diff NUMBER;TYPE t_plant_table IS TABLE OF VARCHAR2(5) INDEX BY BINARY_INTEGER;v_plant_table t_plant_table;v_veh_line_count NUMBER:=0;

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CURSOR c_iterate_veh_lines ISSELECT DISTINCT WERS_9270_CODE FROM VEHICLE V, MKT_MDL MM WHERE

ASSEMBLY_LOCATION_CODE=v_plant AND PRODUCTION_DATE >= v_start_date ANDPRODUCTION_DATE <= v_end_date ANDmm.mkt_mdl_sakey >= 0 and MM.MKT_MDL_SAKEY=V.MKT_MDL_SAKEY AND

MM.WERS_9270_CODE IS NOT NULL; cursor max_bulk (v_plant varchar2, vehicle_line_code varchar2, v_start_date date) is select max(bulk_material_cost) bulkmat from bulk_material_cost t1 where assembly_location_code=v_plant and vehicle_line_code=v_vehicle and effective_date= (select max(effective_date) from bulk_material_cost t2 where t1.assembly_location_code = t2.assembly_location_code and t1.vehicle_line_code = t2.vehicle_line_code and t2.vehicle_line_code = v_vehicle and t2.assembly_location_code= v_plant and effective_date <= v_start_date); cursor sum1(v_curr_start_date date, v_plant varchar2, v_vehicle varchar2 , v_exchange_date date) is

select sum(part_currency_cost*(rate_mult/rate_div)) summ from vehicle_material_cost vmc, ps_rt_rate_tbl_mv er, vehicle v, mkt_mdl MMwhere

V.production_date = v_curr_start_date andV.assembly_location_code=v_plant and

vmc.vehicle_id=v.vehicle_id and

MM.mkt_mdl_sakey=V.mkt_mdl_sakey andmm.wers_9270_code=v_vehicle and

from_cur=vmc.currency_code andto_cur='USD' andrt_type='CRRNT' ander.effdt=v_exchange_date; Notice we are replacing

implicit with explicit

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sum1rec sum1%rowtype;max_bulk_rec max_bulk%rowtype;begin

v_plant_table(1):='AP01A';v_plant_table(2):='AP02A';v_plant_table(3):='AP03A';v_plant_table(4):='AP04A';v_plant_table(5):='AP05A';v_plant_table(6):='AP06A';v_plant_table(7):='AP07A';v_plant_table(8):='AP09A';v_plant_table(9):='AP10A';v_plant_table(10):='AP11A';v_plant_table(11):='AP12A';v_plant_table(12):='AP13A';v_plant_table(13):='AP14A';v_plant_table(14):='AP15A';v_plant_table(15):='AP16A';v_plant_table(16):='AP17A';v_plant_table(17):='AP20A';v_plant_table(18):='AP21A';v_plant_table(19):='AP22A';v_plant_table(20):='AP23A';v_plant_table(21):='AP24A';v_plant_table(22):='0096A';v_plant_table(23):='0097A';v_plant_table(24):='0118A';v_plant_table(25):='0128A';v_plant_table(26):='0129A';v_plant_table(27):='0134A';v_plant_table(28):='0145A';v_plant_table(29):='0264F';v_plant_table(30):='0264A';v_plant_table(31):='02641';dbms_output.put_line('Plant,Veh Line,Bulk Matl Cost,Date,Straight,All,VIN,(VIN-All)%,(VIN-Straight)%,Total VINs,Cost Per VIN');for v_plant_index in 1..31 loop

v_plant:=v_plant_table(v_plant_index);v_veh_line_count:=0;for v_veh_rec in c_iterate_veh_lines loop

v_veh_line_count:=v_veh_line_count+1;v_curr_start_date:=v_start_date;v_vehicle:=v_veh_rec.wers_9270_code;

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for v_plant_index in 1..31 loop v_plant:=v_plant_table(v_plant_index);v_veh_line_count:=0;for v_veh_rec in c_iterate_veh_lines loop

v_veh_line_count:=v_veh_line_count+1;v_curr_start_date:=v_start_date;v_vehicle:=v_veh_rec.wers_9270_code;

open max_bulk (v_plant, v_vehicle, v_start_date);fetch max_bulk into max_bulk_rec;

v_bulk_material:= max_bulk_rec.bulkmat;close max_bulk;

IF v_bulk_material is null then

v_bulk_material:=0;end if;dbms_output.put_line('-');dbms_output.put_line('-');loop

exit when v_curr_start_date > v_end_date; open sum1 (v_curr_start_date , v_plant , v_vehicle , v_exchange_date ); fetch sum1 into sum1rec;

v_vin1 := sum1rec.summ; close sum1; select sum(part_currency_cost *(rate_mult/rate_div)) into v_vin2 from vehicle_material_cost vmc, ps_rt_rate_tbl_mv er, vehicle v, mkt_mdl MM,

vehicle_vin VV, vehicle_suspense VSwhere

V.production_date = v_curr_start_date and

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V.assembly_location_code=v_plant and

vv.vehicle_id=v.vehicle_id and

MM.mkt_mdl_sakey(+)=V.mkt_mdl_sakey andMM.wers_9270_code is null andvmc.vehicle_id=v.vehicle_id ANDvv.vehicle_id = vmc.vehicle_idand vs.plant_code = v.assembly_location_codeand vs.plant_code= v_plant

and

vs.vin=vv.vin and Notice making all joins possiblevs.record_id=(SELECT MAX(RECORD_ID) FROM VEHICLE_SUSPENSE vss where vin=vv.vin and vss.plant_code = v.assembly_location_code and plant_code = v_plant and vss.vehicle_line_code = v_vehicle) andvs.vehicle_line_code=v_vehicle and

from_cur=vmc.currency_code andto_cur='USD' andrt_type='CRRNT' ander.effdt=v_exchange_date;

v_vin:=nvl(v_vin1,0)+nvl(v_vin2,0);select count(*) into v_count from (select distinct v.vehicle_id from vehicle_material_cost vmc, ps_rt_rate_tbl_mv er, vehicle v, mkt_mdl MM,

vehicle_vin VV, vehicle_suspense VSwhere

V.production_date = v_curr_start_date andV.assembly_location_code=v_plant and

MM.mkt_mdl_sakey(+)=V.mkt_mdl_sakey and(MM.wers_9270_code is null or (mm.wers_9270_code=v_vehicle)) and

vmc.vehicle_id=v.vehicle_id AND

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vv.vehicle_id=v.vehicle_id andvs.vin(+)=vv.vin and(vs.vehicle_line_code is null or (vs.vehicle_line_code=v_vehicle and

vs.record_id=(SELECT MAX(RECORD_ID) FROM VEHICLE_SUSPENSE where vin=vv.vin))) and(vs.vehicle_line_code is not null or MM.wers_9270_code is not null) and

from_cur=vmc.currency_code andto_cur='USD' andrt_type='CRRNT' ander.effdt=v_exchange_date);

v_vin:=v_vin-(v_count*v_bulk_material);select sum(price *(rate_mult/rate_div) *accumulated_supplier_quantity) into v_st_line_bom

from daily_flat_bom dfb, ps_rt_rate_tbl_mv er whereproduction_date = v_curr_start_date andassembly_location_code=v_plant and vehicle_line_code=v_vehicle ander.from_cur=dfb.currency_code ander.to_cur='USD' andrt_type='CRRNT' ander.effdt=v_exchange_date;

select sum(ext_purc_material_cost*accumulated_supplier_quantity) into v_all_parts_bom from daily_assembly_end_item_bom where

production_date = v_curr_start_date andassembly_location_code=v_plant and vehicle_line_code=v_vehicle;

v_st_line_bom:=nvl(v_st_line_bom,0);v_all_parts_bom:=nvl(v_all_parts_bom,0);v_vin:=nvl(v_vin,0);

IF v_vin=0 THEN

v_vin_all_perc_diff:=0;

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ELSEv_vin_all_perc_diff:=abs((v_vin-v_all_parts_bom)/(v_vin));

END IF;IF v_vin=0 THEN

v_vin_st_perc_diff:=0;ELSE

v_vin_st_perc_diff:=abs((v_vin-v_st_line_bom)/(v_vin));END IF;IF v_count > 0 THEN

dbms_output.put_line(v_plant||','||v_vehicle||','||v_bulk_material||','||v_curr_start_date||',' ||v_st_line_bom|| ',' ||v_all_parts_bom||','||v_vin||','||v_vin_all_perc_diff||','||v_vin_st_perc_diff||','||v_count||','||v_vin/v_count);v_curr_start_date:=v_curr_start_date+1;

ELSEdbms_output.put_line(v_plant||','||v_vehicle||','||v_bulk_material||','||v_curr_start_date||',' ||v_st_line_bom|| ',' ||v_all_parts_bom||','||v_vin||','||v_vin_all_perc_diff||','||v_vin_st_perc_diff||','||v_count||','||v_count);v_curr_start_date:=v_curr_start_date+1;

END IF;end loop;

end loop;IF v_veh_line_count=0 THEN

dbms_output.put_line('No vehicles with vehicle lines found for plant '||v_plant);END IF;

end loop;end;/ spool off set feedback onset termout on

We need to extract DISTINCT plant, plant description, , vehicle line (TAURUS),Vehicle line description, assembly plant 0096A, assembly plant description(Genk), commodity code (B100), commodity code description ,Market code , market code description (Australia)(batteries) from a table of data (called TVM_market_flat_bom).This is used for a WEB screen drop down

Previous Method: Create a snapshotProblem: Refresh takes too long because Query with DISTINCT AND the function takes much too long. Took about 7 hours.

TVM LOOKUP SCREEN

COMMODITY_CODE

ASSEMBLY_LOCATION_CODETVM_MARKET_FLAT_BOM

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Snapshot

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REPORT_CONTROL_SAKEY NOT NULL NUMBER CALENDAR_YEAR_MONTH NOT NULL VARCHAR2(6) ASSEMBLY_LOCATION_CODE NOT NULL VARCHAR2(5) WERS_9270_CODE NOT NULL VARCHAR2(5) PART_USING_LOCATION_CODE NOT NULL VARCHAR2(5) SHIP_FROM_LOCATION_CODE NOT NULL VARCHAR2(5) CONFIG_STRING NOT NULL VARCHAR2(50) CPSC_CODE NOT NULL VARCHAR2(6) PART_ID NOT NULL NUMBER(9) WERS_MARKET_CODE NOT NULL VARCHAR2(5) PART_PREFIX VARCHAR2(12) PART_BASE NOT NULL VARCHAR2(12) PART_SUFFIX VARCHAR2(12) PART_DESC VARCHAR2(34) CPSC_USAGE_QTY NUMBER(25,15) CONFIG_USAGE_QTY NUMBER(25,15) WERS_9270_USAGE_QTY NUMBER(25,15) MARKET_USAGE_QTY NUMBER(25,15) CONFIG_VOLUME_COUNT NUMBER(38) MARKET_VOLUME_COUNT NUMBER WERS_9270_VOLUME_COUNT NUMBER(38) PERCENT_OF_BUSINESS NUMBER(3,2) PERCENT_OF_BUSINESS_9270 NUMBER(3,2) COMMODITY_CODE VARCHAR2(4) PRICE NUMBER(20,6) PRICE_SOURCE VARCHAR2(240) CURRENCY_CODE VARCHAR2(3) EXCHANGE_RATE NUMBER(15,8) SUPPLIER_TYPE VARCHAR2(240) PRICE_EFFECTIVE_DATE DATE PRICING_RULE VARCHAR2(240) PRICING_SUBRULE VARCHAR2(240) BUYER_CODE VARCHAR2(240) PART_UNIT_OF_MEASURE VARCHAR2(3) CREATE_DTS NOT NULL DATE CREATE_USERID NOT NULL VARCHAR2(8) UPDATE_DTS NOT NULL DATE UPDATE_USERID NOT NULL VARCHAR2(8)

DESC TVM_MARKET_FLAT_BOM

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The query:

CREATE SNAPSHOT MV_TVM_MKT_LOC_LOOKUPTABLESPACE "GCOR7_TABLE" BUILD IMMEDIATEUSING INDEX TABLESPACE "GCOR3_INDEX" PCTFREE 10 INITRANS 2 MAXTRANS 255REFRESH COMPLETE WITH ROWIDASSELECT distinct PART_uSING_LOCATION_CODE, fn_plant_description(part_Using_location_code) part_using_location_name, wers_9270_code,fn_wers9270_description(wers_9270_code) wers_9270_name,assembly_location_code,fn_plant_description(assembly_location_code) assembly_location_name,commodity_code,fn_commodity_code_desc(commodity_code) commodity_desc,wers_market_code,fn_wers_market_desc(wers_market_code) wers_market_namefrom tvm_market_flat_bom;

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The solution:

Instead of Using the slow query from TVM_MARKET_FLAT BOM in creating a snapshot:

1) Create a global temporary table with the proper indexes2) Do a straight select (no distinct) from TVM_MARKET_FLAT_BOM (do not include the functions for the descriptions). 3) At that point put together a procedure to update the descriptions in the in groups by vehicle line in the global temporary table. 4) Use this table and put the information (grouped by assembly location code, wers_9270_code (Taurus), plant, commodity_code) into another table that is indexed, and use THIS table for the look up screen.

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CREATE INDEX I_MV_TMLL on MV_TVM_MKT_LOC_LOOKUP(part_using_location_code,

wers_9270_code, assembly_location_code, commodity_code , wers_market_code);

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Solution: (1) Create a global temporary table and bring information

over to it, then update groups of records. Then put this

information into a separate table for the lookup screens

create global temporary table gl_t1(part_Using_location_code varchar2(5), part_using_location_name varchar2(100), wers_9270_code varchar2(3), wers_9270_name varchar2(100), assembly_location_code varchar2(5), assembly_location_name varchar2(100), commodity_code varchar2(4), commodity_Desc varchar2(100), wers_market_code varchar2(5), wers_market_name varchar2(100) ) on commit preserve rows;

(2) Index columns that are in italics.;

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Elapsed: 00:05:53.74SQL> list 1 insert into gl_t1 2 (part_using_location_code, 3 wers_9270_code, 4 assembly_location_code, 5 commodity_code, 6 wers_market_code 7 ) 8 SELECT PART_uSING_LOCATION_CODE , 9 wers_9270_code, 10 assembly_location_code, 11 commodity_code, 12 wers_market_code 13* from tvm_market_flat_bom@toread

The result:

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• The procedure

• • create or replace procedure updatenames3• is• vwers9270_desc varchar2(200);• vplant_desc varchar2(200);• vcomm_code_desc varchar2(200);• vwersmktcode varchar2(200);• i number := 0;• cursor cs_gl• is• select distinct wers_9270_code from gl_t1;• cs_gl_rec cs_gl%rowtype;• begin• open cs_gl;• loop• fetch cs_gl into cs_gl_rec;• exit when cs_gl%notfound;• vwers9270_desc := fn_wers9270_description(cs_gl_rec.wers_9270_code);

Set up a cursorFor eachDistinct

Vehicle line

Use this function as an example

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• update gl_t1• set wers_9270_name = vwers9270_desc• where wers_9270_code = cs_gl_rec.wers_9270_code;• commit;• end loop;• close cs_gl;• end;• / • SQL> exec updatenames3• PL/SQL procedure successfully completed.• Elapsed: 00:07:48.44 7 MINUTES NOW you can put gl_t1 contents into another tableFor the lookup screen

Update the tableWith the wers_9270_description

QUERY TUNING – As the Oracle Developer- Dont be a target for slow performance.

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