SQL statement tuning

From: Robin Li <rli_at_nyp.org>
Date: Tue, 27 Nov 2007 15:47:27 -0500
Message-id: <474C825F.2050904@nyp.org>

Hi all,

Can someone shed some light on how to tune this sql statement? Oracle version 10.2

SELECT T143.C1,C490021100,C1000000001,C200000020 FROM aradmin.T143
WHERE (((T143.C200000020 LIKE ('Eagle' || '%')) AND (0 = 0)) OR ('Eagle' = ' '));

Execution Plan

Plan hash value: 1317490582

| Id  | Operation                   | Name             | Rows  | Bytes |


------------------------------------------------------------------------

|   0 | SELECT STATEMENT            |                  |  7375 |   388K|
|   1 |  TABLE ACCESS BY INDEX ROWID| T143             |  7375 |   388K|
|*  2 |   INDEX RANGE SCAN          | I143_200000020_1 |  7624 |       |


------------------------------------------------------------------------

Predicate Information (identified by operation id):

2 - access("T143"."C200000020" LIKE 'Eagle%')

filter("T143"."C200000020" LIKE 'Eagle%')

From the trace:

SELECT T143.C1,C490021100,C1000000001,C200000020 FROM aradmin.T143
WHERE (((T143.C200000020 LIKE (:"SYS_B_0" || :"SYS_B_1")) AND (:"SYS_B_2" = :"SY
S_B_3")) OR (:"SYS_B_4" = :"SYS_B_5"))

call     count       cpu    elapsed       disk      query    
current        rows

------- ------ -------- ---------- ---------- ---------- ----------

Parse        1      0.00       0.00          0          0          
0           0
Execute      1      0.00       0.00          0          0          
0           0
Fetch        2     12.10      42.49     126166     130472          
0           1

------- ------ -------- ---------- ---------- ---------- ----------

total        4     12.10      42.49     126166     130472          
0           1

Misses in library cache during parse: 0
Optimizer mode: ALL_ROWS
Parsing user id: 51

Rows Row Source Operation

-------  ---------------------------------------------------
      1  TABLE ACCESS FULL T143 (cr=130472 pr=126166 pw=0 time=129302 us)

Elapsed times include waiting on following events:
  Event waited on                             Times   Max. Wait  Total

Waited

Waited ----------
SQL*Net message to client 2 0.00 0.00 db file sequential read 824 0.03 1.10 db file scattered read 8641 0.06 33.40 SQL*Net message from client 2 0.00 0.00

There are 3.1 million rows for this table, the "Eagle" = " " is used in workflow for a specific function on a remedy application. If I take out the 'OR'(I figure it's always not true), the query runs in milliseconds, the execution plan is the same . The problem is that we can't take the 'OR' out. How can I solve this?

TIA Robin

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Received on Tue Nov 27 2007 - 14:47:27 CST