Re: Re: how to get oracle to ignore an index
- From: "Jonathan Lewis" <jonathan@xxxxxxxxxxxxxxxxxx>
- To: <oracle-l@xxxxxxxxxxxxx>
- Date: Fri, 6 Feb 2004 20:48:28 -0000
You have a little lee-way with that, and a
great pit of confusion. I have a script called
hint_hoho.sql which shows the following:
select n2 from t2 where n1 = 33;
Full tablescan
select /*+ index(t2) */ n2 from t2 where n1 = 33;
Indexed access into t2
select /*+ a complete hint index(t2) */ n2 from t2 where n1 = 33;
Indexed access into t2
select /*+ not a complete hint index(t2) */ n2 from t2 where n1 = 33;
Full tablescan
select /*+ (t1) index(t2) */ n2 from t2 where n1 = 33;
Full tablescan
select /*+ full(t1) index(t2) */ n2 from t2 where n1 = 33;
Indexed access into t2
Version 9.2.0.4
You can get away with some thing which you shouldn't
get away with, and you get hit by some things that you
don't expect to be a problem.
If Oracle spots something that looks like a damaged
hint, it seems to ignore the whole set of hints.
If Oracle sees a load of text that clearly is nothing to do
with hinting, it accepts the hints.
If Oracle sees a hint which is correct in form, but
completely irrelevant, it ignores it, but is happy
with the rest of the hints.
YMMV - YHMFO
Regards
Jonathan Lewis
http://www.jlcomp.demon.co.uk
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who can answer the questions, but the
person who can question the answers -- T. Schick Jr
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----- Original Message -----
From: "Wolfgang Breitling" <breitliw@xxxxxxxxxxxxx>
To: <oracle-l@xxxxxxxxxxxxx>
Sent: Friday, February 06, 2004 6:02 PM
Subject: Re: Re: how to get oracle to ignore an index
Also, if you have multiple hints and have a syntax error somewhere, not
just the malformed hint but also everything following is ignored.
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