From: Bruno Wolff III <bruno@wolff.to>
To: KÖPFERL Robert <robert.koepferl@sonorys.at>
Cc: pgsql-sql@postgresql.org
Subject: Re: can a function return a virtual table?
Date: Tue, 19 Apr 2005 06:11:53 -0500
Message-ID: <20050419111153.GA10314@wolff.to> (raw)
In-Reply-To: <ED4E30DD9C43D5118DFB00508BBBA76EB166BC@neptun.sonorys.at>
References: <ED4E30DD9C43D5118DFB00508BBBA76EB166BC@neptun.sonorys.at>
On Tue, Apr 19, 2005 at 09:34:43 +0200,
KÖPFERL Robert <robert.koepferl@sonorys.at> wrote:
> That was a nice answer - rather compleete.
>
> However at least I am questioning myself for a long time about what happens
> if one does a select from a SRF. The function may return millions of records
> (i.e. select * from x where a>1). Is this data streamed through the query
> process or does postgres create a temporary table.
>
> An "explain select * from srf()" just returns a function invocation. :-/
> How does this work?
If the function isn't written using a language of SQL, it isn't going to
optimize well when you only want to see part of the table.
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To: pgsql-sql@postgresql.org
Cc: bruno@wolff.to, robert.koepferl@sonorys.at
Subject: Re: can a function return a virtual table?
In-Reply-To: <20050419111153.GA10314@wolff.to>
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