Re: Re: patch: fix performance problems with repated decomprimation of varlena values in plpgsql

Pavel Stehule <pavel.stehule@gmail.com>

From: Pavel Stehule <pavel.stehule@gmail.com>

To: Robert Haas <robertmhaas@gmail.com>

Cc: Tom Lane <tgl@sss.pgh.pa.us>, Kevin Grittner <Kevin.Grittner@wicourts.gov>, Noah Misch <noah@leadboat.com>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>

Date: 2011-01-22T10:32:02Z

Lists: pgsql-hackers

Attachments

detoast.patch (text/x-patch) patch

Hello,

because I am not sure so any complex solution can be done to deadline
for 9.1, I created a patch that is based on Tom ideas - just
explicitly detoast function parameters.

Regards

Pavel

2011/1/19 Robert Haas <robertmhaas@gmail.com>:
> On Wed, Jan 19, 2011 at 4:18 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> One idea that I think we discussed was to tie cache entries to the
>> memory context they were demanded in, and mark them unused at the next
>> context reset/delete.  That way they'd be considered unused at the same
>> points where the current implementation would certainly have discarded
>> the value.  This isn't perfect (because of pfree) but might be good
>> enough.
>
> Yeah, I was thinking that's probably what would have to be done.
>
> --
> Robert Haas
> EnterpriseDB: http://www.enterprisedb.com
> The Enterprise PostgreSQL Company
>