RE: Pinning/keeping plans in shared pool - using dbms_advanced_rewrite with query > 2499 characters

From: ramick <ramick_at_dotster.com>
Date: Mon, 10 Jul 2006 15:02:30 -0700
Message-Id: <20060710220238.D57223955CF@turing.freelists.org>

How about using one of the old tricks to force a different plan like col+0 or col || `` on some column where there is not already an index used?

This should make the SQL different...

-----Original Message-----

From: oracle-l-bounce_at_freelists.org [mailto:oracle-l-bounce_at_freelists.org] Sent: Monday, July 10, 2006 1:32 PM
To: Alex Gorbachev
Cc: oracle-l_at_freelists.org
Subject: RE: Pinning/keeping plans in shared pool - using dbms_advanced_rewrite with query > 2499 characters

Okay, I found a problem around that - I broke it up into smaller chunks and concatenated them together, e.g.:

begin
dbms_advanced_rewrite.declare_rewrite_equivalence( name => 'my_query', source_stmt => 'select blah blah blah' ||

'from blah blah blah',
destination_stmt => 'select /*+ RULE */ blah blah blah' ||
'from blah blah blah',

validate => false
rewrite_mode => 'GENERAL');
end;

But, now I'm getting the following error:

ORA-30394: source statement identical to the destination statement

Apparently it ignores differences in hints/comments because I added a RULE hint to the second query. So, I'll have to make some other modification in order for it to accept my query rewrite and try again.

A few other things to note:

1. I made a typo in my previous email - the procedure is "declare_*rewrite*_equivalence" not declare_query_equivalence.
2. There is a documentation bug on this - it says that the 4th argument to the procedure is "mode", but it is actually "rewrite_mode"

Regards,
Brandon

-----Original Message-----

From: oracle-l-bounce_at_freelists.org
[mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Allen, Brandon Sent: Monday, July 10, 2006 1:10 PM
To: Alex Gorbachev
Cc: oracle-l_at_freelists.org
Subject: RE: Pinning/keeping plans in shared pool - using dbms_advanced_rewrite with query > 2499 characters  

I'm trying to use dbms_advanced_rewrite.declare_query_equivalence, but getting error "SP2-0027: Input is too long (> 2499 characters)" because the query is about 6000 characters. Anyone know of a way around this?

Thanks,
Brandon

-----Original Message-----

From: Alex Gorbachev [mailto:gorbyx_at_gmail.com] Sent: Saturday, July 08, 2006 12:06 AM
To: Allen, Brandon
Cc: oracle-l_at_freelists.org
Subject: Re: Pinning/keeping plans in shared pool

I just though that it might be useful to check on DBMS_ADVANCED_REWRITE package and see if you can use it to incorporate certain hints that can make parsing fast.

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http://www.freelists.org/webpage/oracle-l Received on Mon Jul 10 2006 - 17:02:30 CDT