Re: Zedstore - compressed in-core columnar storage

On Thu, Nov 12, 2020 at 4:40 PM Tomas Vondra
<tomas.vondra@enterprisedb.com> wrote:
>            master    zedstore/pglz    zedstore/lz4
>   -------------------------------------------------
>    copy      1855            68092            2131
>    dump       751              905             811
>
> And the size of the lineitem table (as shown by \d+) is:
>
>   master: 64GB
>   zedstore/pglz: 51GB
>   zedstore/lz4: 20GB
>
> It's mostly expected lz4 beats pglz in performance and compression
> ratio, but this seems a bit too extreme I guess. Per past benchmarks
> (e.g. [1] and [2]) the difference in compression/decompression time
> should be maybe 1-2x or something like that, not 35x like here.

I can't speak to the ratio, but in basic backup/restore scenarios pglz
is absolutely killing me; Performance is just awful; we are cpubound
in backups throughout the department.  Installations defaulting to
plgz will make this feature show very poorly.

merlin