Dynamic Query

From: The Magnet <art_at_unsu.com>
Date: Tue, 13 Oct 2009 10:32:20 -0700 (PDT)
Message-ID: <2876db84-c782-4fa3-8729-4ec174acb65f_at_v36g2000yqv.googlegroups.com>

Dynamic queries suck! But, our setup is that we have a table with application stored queries. PHP calls a stored procedure, passing it parameters as well as the name of the query it needs. The stored procedure goes into a table, gets the SELECT statement and creates a dynamic query based on the parameters passed and then opens up a REF CURSOR for PHP to read. Here is an example:

begin for_php.open_php(:data,'ba','SHAREPRICE',:col);end;

So, the query is dynamic which means a hard parse, right? 90% of our application is written this way. It has really sent the latch waits through the roof, which probably causes performance issues.

We've set CURSOR_SHARING = FORCE to help us, but we'd really like to bring the parse count down. Since these are all dynamic, and are not re-used often since the parameters, are we SOL?

Been reading pages like this to look for answers:

http://books.google.com/books?id=14OmJzfCfXMC&pg=PA148&lpg=PA148&dq=oracle+high+latch+free+wait+event&source=bl&ots=KN438VyP3l&sig=8Qt5KLYDu8Gy6Hg7eorSBFWWv_8&hl=en&ei=JhN7SuyeEYykMMGnvP8C&sa=X&oi=book_result&ct=result&resnum=1#v=onepage&q=oracle%20high%20latch%20free%20wait%20event&f=false Received on Tue Oct 13 2009 - 12:32:20 CDT

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