Re: Enabling Checksums

On 13 March 2013 06:33, Jeff Davis <pgsql@j-davis.com> wrote:
> On Thu, 2013-03-07 at 13:45 -0800, Jeff Davis wrote:
>> I need to do another self-review after these changes and some more
>> extensive testing, so I might have missed a couple things.
>
> New patch attached.
>
> Aside from rebasing, I also found a problem with temp tables. At first I
> was going to fix it by continuing to exclude temp tables from checksums
> entirely. But then I re-thought it and decided to just checksum temp
> tables, too.
>
> Excluding temp tables from checksums means more special cases in the
> code, and more documentation. After thinking about it, there is no huge
> benefit to excluding temp tables:
>   * small temp tables will be in memory only, and never checksummed
>   * no WAL for temp tables, so the biggest cost of checksums is
> non-existent
>   * there are good reasons to want to checksum temp tables, because they
> can be used to stage data for permanent tables
>
> However, I'm willing to be convinced to exclude temp tables again.

I'm convinced we must include temp tables. No point putting a lock on
the front door if there's a back door still open.

-- Simon Riggs                   http://www.2ndQuadrant.com/PostgreSQL Development, 24x7 Support, Training & Services