From: Gregory Stark <stark@enterprisedb.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Alvaro Herrera <alvherre@commandprompt.com>
Cc: Simon Riggs <simon@2ndquadrant.com>
Cc: Kim <kim@myemma.com>
Cc: pgsql-performance@postgresql.org
Cc: pgsql-hackers@postgresql.org
Subject: Re: [PERFORM] unusual performance for vac following 8.2upgrade
Date: Fri, 12 Jan 2007 12:43:42 +0000
Message-ID: <874pqwwh35.fsf@stark.xeocode.com> (raw)
In-Reply-To: <29730.1168570299@sss.pgh.pa.us>
References: <45A671CD.1050706@myemma.com>
<27939.1168539652@sss.pgh.pa.us>
<45A68C74.4080405@myemma.com>
<28949.1168544710@sss.pgh.pa.us>
<1168548006.3951.564.camel@silverbirch.site>
<5414.1168549900@sss.pgh.pa.us>
<1168557275.3990.49.camel@silverbirch.site>
<20070112010918.GM10464@alvh.no-ip.org>
<29730.1168570299@sss.pgh.pa.us>
"Tom Lane" <tgl@sss.pgh.pa.us> writes:
> 3. What about dependencies on user-defined types, functions, etc?
> How will you get things to behave sanely if one backend tries to drop a
> type that some other backend is using in a column of a temp table? Even
> if you put entries into pg_depend, which would kind of defeat the point
> of not having on-disk catalog entries for temp tables, I don't see how
> the other backend figures out what the referencing object is.
We could just lock the object it depends on. Only really makes sense for very
temporary tables though, not tables a session expects to use for a long series
of transactions.
Another direction to go to address the same problem would be to implement the
standard temporary table concept of a permanent table definition for which
each session gets a different actual set of data which is reset frequently.
Then the meta-data isn't changing frequently.
--
Gregory Stark
EnterpriseDB http://www.enterprisedb.com
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To: pgsql-performance@postgresql.org
Cc: stark@enterprisedb.com, tgl@sss.pgh.pa.us, alvherre@commandprompt.com, simon@2ndquadrant.com, kim@myemma.com, pgsql-hackers@postgresql.org
Subject: Re: [PERFORM] unusual performance for vac following 8.2upgrade
In-Reply-To: <874pqwwh35.fsf@stark.xeocode.com>
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