Analyzing index increase Query cost
Following is my experience.
SQL> explain plan for
2 update prtcpnt
3 set f9= 1
4 WHERE f3 = :b1
5 AND f4 = :b2
6 AND f2 != :b3
7 /
Explained.
SQL> @showplan
SQL> set echo off
Query Plan COST
-------------------------------------------------------------------------------- ----------
UPDATE STATEMENT [CHOOSE] Cost = 27 27
UPDATE PRTCPNT
INDEX RANGE SCAN PR_TEST 2
SQL>
After that I am analyzing Index, and then Plan shows cost more. What is the reason.
SQL> analyze index pr_test compute statistics;
Index analyzed.
SQL> @expl
SQL> truncate table plan_table;
Table truncated.
SQL> explain plan for
2 update prtcpnt
3 set f9= 1
4 WHERE f3 = :b1
5 AND f4 = :b2
6 AND f2 != :b3
7 /
Explained.
SQL> @showplan
SQL> set echo off
Query Plan COST
-------------------------------------------------------------------------------- ----------
UPDATE STATEMENT [CHOOSE] Cost = 445 445
UPDATE PRTCPNT
INDEX RANGE SCAN PR_TEST [ANALYZED] 56
SQL>
The table contains more than 500000 records.
Re: Analyzing index increase Query cost
Quote:
Originally posted by Dilippatel
After that I am analyzing Index, and then Plan shows cost more. What is the reason.
Try rebuilding the index and then analyze and then try getting execution plan.
Re: Re: Analyzing index increase Query cost
Quote:
Originally posted by nagarjuna
Try rebuilding the index and then analyze and then try getting execution plan.
What do you expect that to do?