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Re: Estimation problem with a LIKE clause containing a / - Mailing list pgsql-performance

From Guillaume Smet
Subject Re: Estimation problem with a LIKE clause containing a /
Date
Msg-id [email protected]
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In response to Re: Estimation problem with a LIKE clause containing a /  (Tom Lane <[email protected]>)
Responses Re: Estimation problem with a LIKE clause containing a /
Re: Estimation problem with a LIKE clause containing a /
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Tom,

On Nov 8, 2007 12:14 AM, Tom Lane <[email protected]> wrote:
> I've applied a patch that might help you:
> http://archives.postgresql.org/pgsql-committers/2007-11/msg00104.php

AFAICS, it doesn't seem to fix the problem. I just compiled
REL8_1_STABLE branch and I still has the following behaviour:
lbo=# ANALYZE cms_items;
ANALYZE
lbo=# explain analyze select * from cms_items where ancestors LIKE '1062/%';
                                                 QUERY PLAN
------------------------------------------------------------------------------------------------------------
 Seq Scan on cms_items  (cost=0.00..688.26 rows=1 width=103) (actual
time=0.009..22.258 rows=11326 loops=1)
   Filter: ((ancestors)::text ~~ '1062/%'::text)
 Total runtime: 29.835 ms
(3 rows)

lbo=# show lc_collate;
 lc_collate
-------------
 fr_FR.UTF-8
(1 row)

Do you see any reason why your patch doesn't change anything in this case?

Thanks.

--
Guillaume

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