Date: Mon, 4 Jan 2016 18:16:40 +0100
From: Andres Freund <andres@anarazel.de>
To: Mark Zealey <mark@allaroundtheworld.fr>
Cc: pgsql-performance@postgresql.org
Subject: Re: Proposal for unlogged tables
Message-ID: <20160104171640.GF28025@awork2.anarazel.de>
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On 2016-01-04 19:12:22 +0200, Mark Zealey wrote:
> If there was a command to flush a specific unlogged table to disk it would
> work around all these issues no? Perhaps if you marked the table as read
> only at the same time it would flush it to disk and ensure no more data
> could be written to it eg (ALTER TABLE ... SET READ ONLY on an unlogged
> table would flush + not truncate after crash). In our case this would be
> great as we want to use these as permanent tables for speed; but after an
> initial data dump we don't change the data again so we could just do this at
> the end of the import process.

It's more complex than that, even unmodified tables need to be processed
by vacuum every now and then (xid wraparound handling). It probably
possible to work around such things, but it's not a line or ten.

Andres


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