From: Jaime Casanova <jcasanov@systemguards.com.ec>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Alvaro Herrera <alvherre@commandprompt.com>
Cc: Nikhil Sontakke <nikhil.sontakke@enterprisedb.com>
Cc: Emmanuel Cecchet <manu@frogthinker.org>
Cc: PostgreSQL-development <pgsql-hackers@postgresql.org>
Subject: Re: Fwd: [PATCHES] Auto Partitioning Patch - WIP version 1
Date: Thu, 27 Nov 2008 09:01:56 -0500
Message-ID: <3073cc9b0811270601m6a7691dcg5f2ea6d4172b0d38@mail.gmail.com> (raw)
In-Reply-To: <603c8f070811270507i36e18e0bu5d461a4f957e24d3@mail.gmail.com>
References: <3073cc9b0810220744y987173avd560a33fcb58ede5@mail.gmail.com>
<490B5178.7070600@frogthinker.org>
<3073cc9b0811052047o4ebe24b4vd0ab24fd3095d342@mail.gmail.com>
<3073cc9b0811261335q5e35d336i33faa17eede7d417@mail.gmail.com>
<603c8f070811261352ta6da0b8xcbb8aaf87f050e6e@mail.gmail.com>
<3073cc9b0811261613l18e5283ft448ea74fed414dd@mail.gmail.com>
<603c8f070811262009v459d0701w151c16533d4ab947@mail.gmail.com>
<a301bfd90811270106k39d60318s7fc871a477a2b58d@mail.gmail.com>
<20081127120402.GC4586@alvh.no-ip.org>
<603c8f070811270507i36e18e0bu5d461a4f957e24d3@mail.gmail.com>
On Thu, Nov 27, 2008 at 8:07 AM, Robert Haas <robertmhaas@gmail.com> wrote:
>
> The semantics of PARTITION ON (<expr>) are unclear to me. I was
> thinking maybe it would make sense to do something like:
>
> CREATE PARTITION <name> ON <table> WHERE <expr>
>
At first look seems nice but s Gregory said the ideal would be to
identify the key partition.
>
> I like the idea of using table inheritance as a foundation for this
> feature, but I think it's not going to be very useful for real-world
> applications without cross-table indexes. Suppose for example that I
> have five years worth of data (thus, 60 partitions) and each
> transaction has a unique identifier of some sort that is unrelated to
> the date. It's bad enough that a query like this has to check every
> partition:
>
you haven't. the WHERE clause in your hipotetical CREATE PARTITION
should create a check constraint on the child (inherited) table and if
you have constraint_exclusion to on you will check just the
partition(s) that match with the check constraint.
>
> What's even worse (at least IMHO) is that there's no way to use
> transaction (uuid) as a reference for a foreign key.
>
not directly, but you always can create a trigger instead of the
foreign key constraint...
mmm...the docs says that there is no good workaround, what about
mention a trigger?
--
Atentamente,
Jaime Casanova
Soporte y capacitación de PostgreSQL
AsesorÃa y desarrollo de sistemas
Guayaquil - Ecuador
Cel. +59387171157
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To: pgsql-patches@postgresql.org
Cc: jcasanov@systemguards.com.ec, robertmhaas@gmail.com, alvherre@commandprompt.com, nikhil.sontakke@enterprisedb.com, manu@frogthinker.org, pgsql-hackers@postgresql.org
Subject: Re: Fwd: [PATCHES] Auto Partitioning Patch - WIP version 1
In-Reply-To: <3073cc9b0811270601m6a7691dcg5f2ea6d4172b0d38@mail.gmail.com>
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