Re: Expensive SQL

From: dombrooks <dombrooks_at_hotmail.com>
Date: Tue, 23 Aug 2011 09:02:46 -0700 (PDT)
Message-ID: <ddd5f73b-6e45-437d-bc6e-c57d152d8a5a_at_e10g2000yqo.googlegroups.com>

Yep - I did just post some additional information but it's not appeared yet.

Although the headline description of the bug mentioned baseline capture, it's very much baseline usage that is also the problem.

I assume you must have some baselined statements in dba_sql_plan_baselines.

The performance bug concerns full table scans on recursive merges into sqlobj$, sqlobj$data and sqlobj$auxdata.

When you execute a baselined statement (even if capture is off), you get at least one lookup on SQLOBJ$ and SQLOBJ$AUXDATA plus a MERGE into the same objects to update the baseline metadata on those statements.

Post patch for 11715191 you still get these statements, but they've been hinted with an INDEX hint

Cheers.
Dominic Received on Tue Aug 23 2011 - 11:02:46 CDT