Re: [HACKERS] Custom compression methods

On 2017-12-01 16:14:58 -0500, Robert Haas wrote:
> Honestly, if we can give everybody a 4% space reduction by switching
> to lz4, I think that's totally worth doing -- but let's not make
> people choose it, let's make it the default going forward, and keep
> pglz support around so we don't break pg_upgrade compatibility (and so
> people can continue to choose it if for some reason it works better in
> their use case). That kind of improvement is nothing special in a
> specific workload, but TOAST is a pretty general-purpose mechanism. I
> have become, through a few bitter experiences, a strong believer in
> the value of trying to reduce our on-disk footprint, and knocking 4%
> off the size of every TOAST table in the world does not sound
> worthless to me -- even though context-aware compression can doubtless
> do a lot better.

+1. It's also a lot faster, and I've seen way way to many workloads with
50%+ time spent in pglz.

Greetings,

Andres Freund