Re: alternative compression algorithms?

On Wed, Apr 29, 2015 at 6:55 PM, Tomas Vondra
<tomas.vondra@2ndquadrant.com> wrote:
> I'm not convinced not compressing the data is a good idea - it suspect it
> would only move the time to TOAST, increase memory pressure (in general and
> in shared buffers). But I think that using a more efficient compression
> algorithm would help a lot.
>
> For example, when profiling the multivariate stats patch (with multiple
> quite large histograms), the pglz_decompress is #1 in the profile, occupying
> more than 30% of the time. After replacing it with the lz4, the data are bit
> larger, but it drops to ~0.25% in the profile and planning the drops
> proportionally.

That seems to imply a >100x improvement in decompression speed.  Really???

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company