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8/9/2019 Tuning Query
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QUERY TUNING
As the Oracle Developer-Dont 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 columns
Which 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 are
Going after in the table. For example, for an employee table, you want the index on social
Security number (a unique value). BUT, if you were going to search on name, you would
Want an index specifically on the NAME column.
Querying the Oracle table:Set up your query in such a way that Oracle
Will use the index of the columns that you
Are 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 (>,
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Basic trouble spots for sql queriesBasic trouble spots for sql queries
(continued)(continued)
(3) Using is null and is not null. (Continued)Select *
FROM s_emp
WHERE
Title 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 to
Basic trouble spots for sql queriesBasic trouble spots for sql queries
Problem:Problem:1. Using a function on the left side.
Select * from s_emp
Where substr(title,1,3) = Man;
Select * from s_emp
Where trunc(hire_date) = trunc(sysdate);
Solution:
Use like
Select * from s_emp
Where title like Man%;
Use >, = sysdate
and hire_date < sysdate + 1;
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Solutions toSolutions to
Basic trouble spots for sql queriesBasic trouble spots for sql queries
(continued)(continued)
Problem:Problem:
2. Comparing incompatible data types.
Select * from s_emp
Where employee_number = 3;
Select * from s_emp
Where hire_date = 12-jan-01;
Solution:
Select * from s_emp
Where employee_number = 3;
Select * from s_emp
Where hire_date = to_date(12-jan-01);
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Solutions toSolutions to
Basic trouble spots for sql queriesBasic trouble spots for sql queries
(continued)(continued)
Problem:Problem:
3. Using null and not null
Select * from s_emp
Where title is not null;
Select * from s_emp
Where 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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Solutions toSolutions to
Basic trouble spots for sql queriesBasic trouble spots for sql queries
(continued)(continued)
Problem:Problem:
4. Adding additional criteria in the where clause for a column name that is of a
different index
Select * from s_emp
where title= Managerand 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_tableWHEREstatement_id = 'TEST';
EXPLAIN PLAN SETstatement_id = 'TEST' FOR
{query};
Put this in an sql file called explain.sql
Then do @explain from SQL
Set up a query to go after the plan_table:
select lpad(' ',2*level) || operation || ' ' || Options || ' ' || object_name
execution_path
from plan_tablewhere statement_id = 'TEST
connect by priorid = parent_id and statement_id = 'TEST
start with ID=1;
Put this in an sql file called @explain2.sql
Then 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--------------------------------------------------------------------------------
TABLEACCESS BY INDEXROWID VEHICLE
INDEXRANGESCAN FKI_VEHICLE_1
SORTAGGREGATE
TABLEACCESS BY INDEXROWID VEHICLE
INDEXRANGESCAN FKI_VEHICLE_1
EXECUTION_PATH
--------------------------------------------------------------------------------
SORTAGGREGATE
TABLEACCESS FULL VEHICLE
SORTAGGREGATE
SORTAGGREGATETABLEACCESS 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 queries
1. Find out what indexes are on the tables
2. Run explain plan
3. 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 joins
7. Use exists subquery if only selecting items from 1 table.
The query:
select count(*) from vehicle
Where assembly_location_code = 'AP24A'
and production_date = '06-apr-01';
This will select vin (vehicle ID , Marketinformation,and otherinformation 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 name
Assembly_location_code FKI_VEHICLE_1
Production_date FK_PROD
UCTION_DA
TE
Vehicle id FKI_PRODUCTION_DATE
Vehicle_id PK_V EHICLE
(2) Run an explain plan on this queryIn explain.sql
DELETEFROM plan_tableWHERE statement_id = 'TEST';
EXPLAIN PLAN SETstatement_id = 'TEST' FOR
select count(*) from vehicle
where
assembly_location_code = 'AP24A'
and production_date = '06-apr-01'; --> Notice that an index will still not be used
@explain.sql
@explain2.sql
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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 vehicle
where
assembly_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) meansthat 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' FOR
select /*+ index(vehicleFKI_VEHICLE_1) */ count(*) from vehiclewhere
assembly_location_code = 'AP24A'
and production_date = '06-apr-01'; --> Notice the FKI_VEHICLE_1 hint 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_VEHICLE_1
SORT AGGREGATE
TABLE ACCESS BY INDEX ROWID VEHICLE
INDEX 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 vehicle
where
assembly_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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(3) Tuning of SQL queries(cont)(3) Enable indexes to be used ELIMINATE TABLE ACCESS FULL (continued)
--------------------> This is where the query does use an index
SQL> 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';
5
SQL> set timing on
SQL> @tt
COUNT(*)
----------
787
Elapsed: 00:00:00.88 ------> Notice it is less than 1 second
USE 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 summarizes
The cost of the vehicles) The vehicle table is informationabout the vehicle)
select /*+ index(t1 PK_VEHICLE_MATERIAL_COST) */ count(*) from
vehicle_material
_cost t1where vehicle_id in
(select /*+ index(t2 fki_vehicle_1) -- SAMEINDEXAS BEFOREvehicle_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_DATE
I_VEHICLE_5
ASSEMBLY_LOCATION_CODE
I_VEHICLE_5
WE NEED AN INDEX that uses BOTH production date
And ASSEMBLY_LOCATION_CODE:
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SQL> set timing on
SQL> 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_id4 from vehicle t2 where
5 t1.vehicle_id =t2.vehicle_id6 and assembly_location_code = 'G9W1A'
7 and production_date = '22-apr-03'
8 and rownum 0
10* and currency_code > ' '
SQL> /
COUNT(*)
----------
1803
Elapsed: 00:00:00.46
Now, if we use the proper index (I_VEHICLE_5) the query
Will 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, t3
where t1.emp_id = t2.emp_id
and t2.emp_id = t3.emp_id
add:
select * from t1, t2, t3
where t1.emp_id = t2.emp_id
and t2.emp_id = t3.emp_id
and 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)
The tuned query:set timing on
SELECT
/*+ index (cpat_gvp_extract_mainCGEM_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%')
(4) Tuning of SQL queries
Real life example (continued)
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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.
(4) Tuning of SQL queries
Real life example (continued)
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(4) Tuning of SQL queries
Real life example (continued)
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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(4) Tuning of SQL queries
Real life example (continued)
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_SETTLEMENTNOTICE 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
(4) Tuning of SQL queries
Real life example (continued)RESULTS OF Explain plan:
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(4) Tuning of SQL queries
Real life example (continued)
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 clause
andIB.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(+) ANDIB.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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(4) Tuning of SQL queries
Real life example (continued)RESULTS OF Explain plan:
EXEC
UTION_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 USEDINDEX 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 OUTERNESTED 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
(4) Tuning of SQL queries
Real life example (continued)RESULTS OF Explain plan continued:
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Real life example (continued)
Suppose you have to select all of the employees that are
Not 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_empwhere
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 employees that are
Not 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 t1
Where
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_id
where 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 A
WHERE A.PART_USING_LOCATION_CODE=V_PLANT
AND A.PART_ID =V_PART_ID
AND A.PERCENT_OF_BUSINESS>0
AND 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
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 IS
SELECT PART_ID,
PART_USING_LOCATION_CODE,
SHIP_FROM_LOCATION_CODE,
APP_PEND_INDICATOR
FROM TEMP_PARTSOURCE_DIFFER;
(5) T i f PL SQL d ( ti d)
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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_PLANT
AND A.PART_ID =V_PART_ID
AND A.PERCENT_OF_BUSINESS>0
AND 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
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 off
set 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 = 0 andMM.MKT_MDL_SAKEY=V.MKT_MDL_SAKEY ANDMM.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 t1whereassembly_location_code=v_plantand vehicle_line_code=v_vehicleand effective_date= (select max(effective_date) from bulk_material_cost t2
where t1.assembly_location_code = t2.assembly_location_codeand t1.vehicle_line_code = t2.vehicle_line_code
and t2.vehicle_line_code = v_vehicleand t2.assembly_location_code= v_plantand effective_date
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sum1rec sum1%rowtype;max_bulk_rec max_bulk%rowtype;
beginv_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 loopv_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 loopv_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 thenv_bulk_material:=0;
end if;dbms_output.put_line('-');
dbms_output.put_line('-');
loopexit 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 VS
whereV.production_date = v_curr_start_date 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 and
to_cur='USD' andrt_type='CRRNT' and
er.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 and
assembly_location_code=v_plant and vehicle_line_code=v_vehicle and
er.from_cur=dfb.currency_code ander.to_cur='USD' andrt_type='CRRNT' and
er.effdt=v_exchange_date;
select sum(ext_purc_material_cost*accumulated_supplier_quantity) intov_all_parts_bom from daily_assembly_end_item_bom where
production_date = v_curr_start_date and
assembly_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;
ELSE
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_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 on
set termout on
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We need to extractDISTINCT 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 snapshot
Problem: Refresh takes too long because Query with
DISTINCT AND the function takes much too long. Took
about7 hours.TVM LOOKUP SCREEN
COMMODITY_CODE
ASSEMBLY_LOCATION_CODETVM_MARKET_FLAT_BOM
43
Snapshot
DESC TVM MARKET FLAT BOM
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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_LOOKUP
TABLESPACE "GCOR7_TABLE"
BUILD IMMEDIATEUSING INDEX TABLESPACE "GCOR3_INDEX" PCTFREE 10
INITRANS 2 MAXTRANS 255
REFRESH COMPLETE WITH ROWID
AS
SELECT 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_name
from 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 indexes
2) 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 groupsby 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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Solution: (1) Create a global temporary
table and bring information
over to it, then updategroups of records. Then put thisinformation into aseparate table for the lookupscreens
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:
The procedure
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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 cursor
For each
DistinctVehicle 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 table
With the wers_9270_description