Re: [HACKERS] Big IN() clauses etc : feature proposal

From: "Zeugswetter Andreas DCP SD" <ZeugswetterA(at)spardat(dot)at>
To: "Jim C(dot) Nasby" <jnasby(at)pervasive(dot)com>, "PFC" <lists(at)peufeu(dot)com>
Cc: "Greg Stark" <gsstark(at)mit(dot)edu>, "Tom Lane" <tgl(at)sss(dot)pgh(dot)pa(dot)us>, <pgsql-performance(at)postgresql(dot)org>, <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: [HACKERS] Big IN() clauses etc : feature proposal
Date: 2006-05-11 07:55:15
Message-ID: E1539E0ED7043848906A8FF995BDA57901053F20@m0143.s-mxs.net
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers pgsql-performance


> Something else worth considering is not using the normal
> catalog methods
> for storing information about temp tables, but hacking that together
> would probably be a rather large task.

But the timings suggest, that it cannot be the catalogs in the worst
case
he showed.

> 0.101 ms BEGIN
> 1.451 ms CREATE TEMPORARY TABLE tmp ( a INTEGER NOT NULL, b INTEGER
NOT
> NULL, c TIMESTAMP NOT NULL, d INTEGER NOT NULL ) ON COMMIT DROP

1.4 seconds is not great for create table, is that what we expect ?

> 0.450 ms INSERT INTO tmp SELECT * FROM bookmarks ORDER BY annonce_id
DESC
> LIMIT 20
> 0.443 ms ANALYZE tmp
> 0.365 ms SELECT * FROM tmp
> 0.310 ms DROP TABLE tmp
> 32.918 ms COMMIT
>
> CREATING the table is OK, but what happens on COMMIT ? I hear
the disk
> seeking frantically.

The 32 seconds for commit can hardly be catalog related. It seems the
file is
fsynced before it is dropped.

Andreas

Responses

Browse pgsql-hackers by date

  From Date Subject
Next Message Volkan YAZICI 2006-05-11 08:25:30 Re: intarray internals
Previous Message Marko Kreen 2006-05-11 07:55:01 Re: BEGIN inside transaction should be an error

Browse pgsql-performance by date

  From Date Subject
Next Message Martijn van Oosterhout 2006-05-11 08:30:25 Re: [HACKERS] Big IN() clauses etc : feature proposal
Previous Message PFC 2006-05-11 07:05:56 Re: Speed Up Offset and Limit Clause