Fine tunning the query which uses /*+ USE_CONCAT */ table hint

Question

Some of the queries in our application uses the /*+ USE_CONCAT */ table hint which takes huge time for the execution in Oracle database.when we fire the below query in 250Million production database it takes approx.3min for the execution.
Because of this we are facing a performance issue in the application.
Below is the sample query :
SELECT /*+ USE_CONCAT */ * FROM DI_MATCH_KEY WHERE NORM_COUNTRY_CD = 'US'
AND ((( NORM_CONAME_KEY1 ='WILM I' OR NORM_CONAME_KEY2 = 'WILM I' OR NORM_CONAME_KEY23 = 'WILM I'
OR NORM_CONAME_KEYFIRST ='WILLIAM' ) AND NORM_STATE_PROVINCE = 'CA' ) OR NORM_ADDR_KEY2 = 'CALMN 12 3 OSAI')
Regarding the indexes almost for all the columns combination for the above sql index already created in table.
Your suggestions will be appreciated
Thanks,
Regards,
Krishna kumar

Answer 1

Hi,
Thanks for our valuable inputs.
As suggested find attached explain plan and trace file details in the excel sheet.
TRACE FILE:
<pre>
TKPROF: Release 10.2.0.1.0 - Production on Thu Feb 14 11:11:59 2008
Copyright (c) 1982, 2005, Oracle. All rights reserved.
Trace file: implhr01_ora_26457.trc
Sort options: prsela exeela fchela
count = number of times OCI procedure was executed
cpu = cpu time in seconds executing
elapsed = elapsed time in seconds executing
disk = number of physical reads of buffers from disk
query = number of buffers gotten for consistent read
current = number of buffers gotten in current mode (usually for update)
rows = number of rows processed by the fetch or execute call
SELECT /*+ USE_CONCAT */ COUNT(*) FROM DI_MATCH_KEY WHERE NORM_COUNTRY_CD = 'US'
AND ((( NORM_CONAME_KEY1 ='WILM I' OR NORM_CONAME_KEY2 = 'WILM I' OR NORM_CONAME_KEY23 = 'WILM I'
OR NORM_CONAME_KEYFIRST ='WILLIAM' ) AND NORM_STATE_PROVINCE = 'CA' ) OR NORM_ADDR_KEY2 = 'CALMN 12 3 OSAI')
call count cpu elapsed disk query current rows
Parse 1 0.03 0.05 0 0 0 0
Execute 1 0.00 0.00 0 0 0 0
Fetch 2 3.97 65.43 30633 64053 0 1
total 4 4.00 65.49 30633 64053 0 1
Misses in library cache during parse: 1
Optimizer mode: ALL_ROWS
Parsing user id: 76
Rows Row Source Operation
1 SORT AGGREGATE (cr=64053 pr=30633 pw=0 time=65436584 us)
73914 CONCATENATION (cr=64053 pr=30633 pw=0 time=61623673 us)
0 TABLE ACCESS BY INDEX ROWID DI_MATCH_KEY (cr=4 pr=2 pw=0 time=32617 us)
0 INDEX RANGE SCAN MKADDR_KEY2 (cr=4 pr=2 pw=0 time=32599 us)(object id 122583)
75 TABLE ACCESS BY INDEX ROWID DI_MATCH_KEY (cr=80 pr=20 pw=0 time=1369427 us)
75 INDEX RANGE SCAN MK_CY_KEY1_ST_PROV (cr=5 pr=0 pw=0 time=2119 us)(object id 122666)
2 TABLE ACCESS BY INDEX ROWID DI_MATCH_KEY (cr=81 pr=2 pw=0 time=26723 us)
77 INDEX RANGE SCAN MK_CY_KEY2_ST_PROV (cr=4 pr=0 pw=0 time=3641 us)(object id 122667)
2 TABLE ACCESS BY INDEX ROWID DI_MATCH_KEY (cr=6 pr=0 pw=0 time=47 us)
2 INDEX RANGE SCAN MK_CY_KEY1_AGN (cr=4 pr=0 pw=0 time=28 us)(object id 122670)
73835 TABLE ACCESS BY INDEX ROWID DI_MATCH_KEY (cr=63882 pr=30609 pw=0 time=61503773 us)
73905 INDEX RANGE SCAN MK_CY_KEY2_AGN (cr=266 pr=176 pw=0 time=148198 us)(object id 122745)
alter session set sql_trace true
call count cpu elapsed disk query current rows
Parse 0 0.00 0.00 0 0 0 0
Execute 1 0.00 0.00 0 0 0 0
Fetch 0 0.00 0.00 0 0 0 0
total 1 0.00 0.00 0 0 0 0
Misses in library cache during parse: 0
Misses in library cache during execute: 1
Optimizer mode: ALL_ROWS
Parsing user id: 76
OVERALL TOTALS FOR ALL NON-RECURSIVE STATEMENTS
call count cpu elapsed disk query current rows
Parse 1 0.03 0.05 0 0 0 0
Execute 2 0.00 0.00 0 0 0 0
Fetch 2 3.97 65.43 30633 64053 0 1
total 5 4.00 65.50 30633 64053 0 1
Misses in library cache during parse: 1
Misses in library cache during execute: 1
OVERALL TOTALS FOR ALL RECURSIVE STATEMENTS
call count cpu elapsed disk query current rows
Parse 9 0.05 0.03 0 0 0 0
Execute 23 0.05 0.08 0 0 0 0
Fetch 98 0.01 0.01 0 137 0 76
total 130 0.11 0.13 0 137 0 76
Misses in library cache during parse: 9
Misses in library cache during execute: 9
2 user SQL statements in session.
23 internal SQL statements in session.
25 SQL statements in session.
Trace file: implhr01_ora_26457.trc
Trace file compatibility: 10.01.00
Sort options: prsela exeela fchela
1 session in tracefile.
2 user SQL statements in trace file.
23 internal SQL statements in trace file.
25 SQL statements in trace file.
11 unique SQL statements in trace file.
561 lines in trace file.
91 elapsed seconds in trace file.
</pre>
EXPLAIN PLAN:
<pre>
ID     OPERATION     OBJECT_NAME     CARDINALITY     BYTES     COST     CPU_COST
0     SELECT STATEMENT          1     53     1886     15753172
1     SORT          1     53          
2     CONCATENATION                         
3     TABLE ACCESS     DI_MATCH_KEY     8     424     10     78334
4     INDEX     MKADDR_KEY2     8          4     30086
5     TABLE ACCESS     DI_MATCH_KEY     3     159     7     53574
6     INDEX     MK_CY_KEY1_ST_PROV     3          4     29286
7     TABLE ACCESS     DI_MATCH_KEY     3     159     7     53740
8     INDEX     MK_CY_KEY2_ST_PROV     3          4     29286
9     TABLE ACCESS     DI_MATCH_KEY     5     265     7     55941
10     INDEX     MK_CY_KEY1_AGN     5          4     29686
11     TABLE ACCESS     DI_MATCH_KEY     2192     116176     1855     15511582
12     INDEX     MK_CY_KEY2_AGN     2228          12     524136
</pre>
Kindly help us regarding this.
Thanks,
Krishna Kumar.