Re: [Bizgres-general] WAL bypass for INSERT, UPDATE and

From: Martijn van Oosterhout <kleptog(at)svana(dot)org>
To: Rod Taylor <pg(at)rbt(dot)ca>
Cc: Greg Stark <gsstark(at)mit(dot)edu>, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, Qingqing Zhou <zhouqq(at)cs(dot)toronto(dot)edu>, pgsql-hackers(at)postgresql(dot)org
Subject: Re: [Bizgres-general] WAL bypass for INSERT, UPDATE and
Date: 2005-12-24 08:23:42
Message-ID: 20051224082342.GA8707@svana.org
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

On Fri, Dec 23, 2005 at 11:19:01PM -0500, Rod Taylor wrote:
> > In many cases you could use temporary tables, but sometimes you might want
> > multiple processes or multiple transactions to be able to see the data.
>
> Could always implement GLOBAL TEMP tables that have the ability to use
> these kinds of shortcuts.

Indeed, that's the thought I get while reading this thread.

TEMP tables are not xlogged

For global temp tables I'd suggest creating a schema pg_globaltemp or
some such where:

1. No Xlog, like TEMP tables
2. Use shared buffer cache like normal tables.
3. On startup after unclean shutdown, delete anything in that schema

And (AFAIK) we get extra SQL complience to boot. If you really want an
extension, how about one to un-TEMP-ify a temp table.

That would allow the following:

CREATE GLOBAL TEMP TABLE blah INHERITS myhugetable;

-- Load data, munge, etc... no xlog traffic
-- If system crashes here, nothing to recover

ALTER TABLE blah ALTER SCHEMA TO public; -- untempify

-- If PITR, write Xlog data now
-- If no PITR, just move file and update catalog

How does this not do what people are asking for?
--
Martijn van Oosterhout <kleptog(at)svana(dot)org> http://svana.org/kleptog/
> Patent. n. Genius is 5% inspiration and 95% perspiration. A patent is a
> tool for doing 5% of the work and then sitting around waiting for someone
> else to do the other 95% so you can sue them.

In response to

Responses

Browse pgsql-hackers by date

  From Date Subject
Next Message Tatsuo Ishii 2005-12-24 09:25:33 bugs with certain Asian multibyte charsets
Previous Message Greg Stark 2005-12-24 07:01:17 Re: [Bizgres-general] WAL bypass for INSERT, UPDATE and