Re: Need Help on wal_compression

On Tue, Jan 9, 2018 at 1:53 AM, Rambabu V <ram(dot)wissen(at)gmail(dot)com> wrote:

> Hi Team,
>
> Daily 4000 Archive files are generating and these are occupying more
> space, we are trying to compress wall files with using wal_compression
> parameter, but we are not seeing any change in wal files count, could you
> please help us on this.
>

If the number of files is driven by archive_timeout, then no reduction in
the number of them would be expected by turning on wal_compression.

If the number of files is driven by the 16MB limit on each file, then it is
surprising that wal_compression did not change it. (But the difference
might not be all that large, depending on the type of transactions and data
you are working with.)

I use an external compression program, xz, which compresses very well. But
it is slow and has trouble keeping up at times of peak activity (e.g. bulk
loads or updates, or reindexing). It reduces the aggregate size, but not
the number of files.

Cheers,

Jeff