Re: O9i: general index question

sybrandb_at_hccnet.nl schrieb am 28.03.2007 in <3v7l03hnh3bgc08tmhkj46u3653m1a8mpo_at_4ax.com>:

> On Wed, 28 Mar 2007 17:57:21 +0200, Andreas Mosmann
> <mosmann_at_expires-31-03-2007.news-group.org> wrote:

> function based index on id_master
> decode(id_master,'0','0',null)

I tried it but Oracle did not use this Index :( CREATE INDEX MyIndex ON TREES (DECODE(IDPARKING,'P0',NULL,IDPARKING)) because I only want to have trees on PARKINGs (about 0.01%)

> NULL values are not indexed.

now I try to replace R0 by NULL

> Obviously you where clause would need the above predicate for the FBI
> to be used (and query_rewrite should be set to true)
Sorry, I did not understand correctly. The WHERE clause is still the following:
WHERE IDPARKING = 'P0' so I would hope it finds out that MyIndex fits. with query_rewrite I played never before, I will try it out.

Thank you
Andreas Mosmann

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