optimizer parameters

From: ed lewis <eglewis71_at_gmail.com>
Date: Sun, 24 Apr 2011 08:22:51 -0400
Message-ID: <BF72764CAF584D9CBEFBB270332C1568_at_CATHY>


   I'm curious what other peoples's experience, suggestions are in regard to the use of the "optimizer_index_caching", and "optimizer_index_cost_adj" parameters.

    As a general practice, I leave them at their defaults, unIess the vendor specifically requires that they be modifed. I use system statistics instead. I haven't find the need to do otherwise. I've tested these parameters on queries, and have received various results. In some cases, it made use of an index, and in other cases, it had no impact.

    I'm not a fan of changing this in midstream for an app that has been running for almost 2 years. This particular vendor is asking to modify this, as a possible solution to a slow-running query. I'm pushing back, and would rather address this in other ways, such as tracing the query, and go from there.

    Your input is appreciated.


solaris 10
rac, asm

Received on Sun Apr 24 2011 - 07:22:51 CDT

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