From: Tom Lane <tgl@sss.pgh.pa.us>
To: Merlin Moncure <mmoncure@gmail.com>
Cc: Heikki Linnakangas <heikki@enterprisedb.com>
Cc: Dean Rasheed <dean_rasheed@hotmail.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: Slow set-returning functions
Date: Sun, 20 Jan 2008 13:30:35 -0500
Message-ID: <10405.1200853835@sss.pgh.pa.us> (raw)
In-Reply-To: <b42b73150801200725y45600f6end8d234cea4f8ff22@mail.gmail.com>
References: <BAY113-W283034364555E644CD1765F23C0@phx.gbl>
<47935C0C.4090908@enterprisedb.com>
<b42b73150801200725y45600f6end8d234cea4f8ff22@mail.gmail.com>
"Merlin Moncure" <mmoncure@gmail.com> writes:
> prepared statements have the same problem. IIRC the planner assumes
> 10%, which will often drop to a seqscan or a bitmap index scan. Some
> years back I argued (unsuccessfully) to have the planner guess 100
> rows or something like that. Ideally, I think it would generate the
> plan from the value passed into the first invocation of the function.
I believe it's the case that that will happen now in the same contexts
where the planner uses the first value of any other parameter (ie,
unnamed statements in the extended-query protocol).
regards, tom lane
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To: pgsql-performance@postgresql.org
Cc: tgl@sss.pgh.pa.us, mmoncure@gmail.com, heikki@enterprisedb.com, dean_rasheed@hotmail.com
Subject: Re: Slow set-returning functions
In-Reply-To: <10405.1200853835@sss.pgh.pa.us>
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