Re: pluggable compression support

On 2013-06-14 17:12:01 -0700, Josh Berkus wrote:
> On 06/14/2013 04:01 PM, Andres Freund wrote:
> > It still contains a guc as described in the above message to control the
> > algorithm used for compressing new tuples but I think we should remove
> > that guc after testing.
>
> Did you add the storage attribute?

No. I think as long as we only have pglz and one new algorithm (even if
that is lz4 instead of the current snappy) we should just always use the
new algorithm. Unless I missed it nobody seemed to have voiced a
contrary position?
For testing/evaluation the guc seems to be sufficient.

If we want to make it configurable on a per column basis I think the way
to go is to add a new column to pg_attribute and split compression
related things out of attstorage into attcompression.
That's a fair amount of work and it includes a minor compatibility break
in the catalog format, so I'd prefer not to do it until there's a good
reason to do so.

Greetings,

Andres Freund

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Andres Freund http://www.2ndQuadrant.com/
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