RE: Performance Problems Solaris Vs Windows

Thu, 12 Jun 2003 01:12:39 -0700

When I specify the STAR Hint in the Query the Query runs OK.
 

Regards
Munish Bajaj 

-----Original Message-----
From: Munish Bajaj [mailto:[EMAIL PROTECTED]
Sent: Thursday, June 12, 2003 11:44
To: Multiple recipients of list ORACLE-L
Subject: RE: Performance Problems Solaris Vs Windows

Both the Tables have been analyzed. I'm trying to find the difference between init parameters.
 
Regards
Munish Bajaj
-----Original Message-----
From: Ishwar Tewari [mailto:[EMAIL PROTECTED]
Sent: Thursday, June 12, 2003 00:30
To: Multiple recipients of list ORACLE-L
Subject: RE: Performance Problems Solaris Vs Windows

Do u analyze both sets of tables on the different platforms at the same regular intervals?
 
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]On Behalf Of Munish Bajaj
Sent: Wednesday, June 11, 2003 12:35 PM
To: Multiple recipients of list ORACLE-L
Subject: Performance Problems Solaris Vs Windows

Hi Gurus,

I'm facing a weird problem. I'm running a same query on windows as well as on Solaris both having Oracle 8.0.5 database using CBO optimizer. The Query runs fine on Windows (takes 20-30 Secs) while the same hangs on Solaris and takes 4-6 hrs to return the results. Both the databases have approx same number of rows and indexes.

The Query is :

SELECT COUNT(*)
    FROM mam_assets a, mam_asset_attr_domain_values dmv65549
    WHERE a."ID" = dmv65549.asset_id
      AND a."ID" IN (SELECT dmv3.asset_id
                         FROM mam_asset_attr_domain_values dmv3
                         WHERE dmv3.domain_value_id = 71
                           AND dmv3.asset_attribute_xid = 3
                           AND dmv3.domain_xid = 7)
      AND a."ID" IN (SELECT dmv3.asset_id
                         FROM mam_asset_attr_domain_values dmv3
                         WHERE dmv3.domain_value_id = 71
                           AND dmv3.asset_attribute_xid = 3
                           AND dmv3.domain_xid = 7)

Explain Plan on Solaris

16 border=0 SELECT STATEMENT
15 border=0 SORT (AGGREGATE)
14 border=0 NESTED LOOPS
12 border=0 NESTED LOOPS
10 border=0 MERGE JOIN (CARTESIAN)
4 border=0 VIEW
3 border=0 SORT (UNIQUE)
2 border=0 TABLE ACCESS (BY INDEX ROWID), MAM_ASSET_ATTR_DOMAIN_VALUES (GMASTER)
1 border=0 INDEX (RANGE SCAN), ATRVALDOM_DOMVAL_FK_I (GMASTER)
9 border=0 SORT (JOIN)
8 border=0 VIEW
7 border=0 SORT (UNIQUE)
6 border=0 TABLE ACCESS (BY INDEX ROWID), MAM_ASSET_ATTR_DOMAIN_VALUES (GMASTER)
5 border=0 INDEX (RANGE SCAN), ATRVALDOM_DOMVAL_FK_I (GMASTER)
11 border=0 INDEX (UNIQUE SCAN), AST_PK (GMASTER)
13 border=0 INDEX (RANGE SCAN), ATRVALDOM_AST_FK_I (GMASTER)

Explain Plan on Windows

15 border=0 SELECT STATEMENT
14 border=0 SORT (AGGREGATE)
13 border=0 NESTED LOOPS
11 border=0 HASH JOIN
4 border=0 VIEW
3 border=0 SORT (UNIQUE)
2 border=0 TABLE ACCESS (BY INDEX ROWID), MAM_ASSET_ATTR_DOMAIN_VALUES (QUARKDMS)
1 border=0 INDEX (RANGE SCAN), ATRVALDOM_DOMVAL_FK_I (QUARKDMS)
10 border=0 NESTED LOOPS
8 border=0 VIEW
7 border=0 SORT (UNIQUE)
6 border=0 TABLE ACCESS (BY INDEX ROWID), MAM_ASSET_ATTR_DOMAIN_VALUES (QUARKDMS)
5 border=0 INDEX (RANGE SCAN), ATRVALDOM_DOMVAL_FK_I (QUARKDMS)
9 border=0 INDEX (UNIQUE SCAN), AST_PK (QUARKDMS)
12 border=0 INDEX (RANGE SCAN), ATRVALDOM_AST_FK_I (QUARKDMS)

As u can clearly see that on Solaris the Oracle does a Merge Join (Cartesian) which is very expensive and hence takes a lot of time.

Please help me understand this and provide any solution if possible.

Thanks to One and all

Best Regards

Munish Bajaj

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