From: Tom Lane <tgl@sss.pgh.pa.us>
To: Fayza Sultan <fayza.sultan@gmail.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: Enabling constraint_exclusion does not avoid scanning all child partitions
Date: Sun, 03 Dec 2006 17:25:27 -0500
Message-ID: <24770.1165184727@sss.pgh.pa.us> (raw)
In-Reply-To: <38443e510612031421y3d8f8f05x8befb7adc166717d@mail.gmail.com>
References: <38443e510612031421y3d8f8f05x8befb7adc166717d@mail.gmail.com>
"Fayza Sultan" <fayza.sultan@gmail.com> writes:
> CREATE TABLE parent (
> monthdate date NOT NULL,
> id int4 NOT NULL,
> CONSTRAINT parent_idx PRIMARY KEY (monthdate,id )
> );
> CREATE TABLE child1
> (
> CONSTRAINT child1_idx PRIMARY KEY (monthdate,id),
> CONSTRAINT child1_chk CHECK (monthdate >= '2006-01-01 00:00:00'::timestamp
> without time zone AND monthdate < '2006-02-01 00:00:00'::timestamp without
> time zone)
monthdate is date, not timestamp. See the caveat in the documentation
about avoiding cross-type comparisons when formulating constraints for
constraint exclusion to use.
regards, tom lane
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To: pgsql-performance@postgresql.org
Cc: tgl@sss.pgh.pa.us, fayza.sultan@gmail.com
Subject: Re: Enabling constraint_exclusion does not avoid scanning all child partitions
In-Reply-To: <24770.1165184727@sss.pgh.pa.us>
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