On Thu, Mar 15, 2012 at 10:14:12PM +0000, Simon Riggs wrote: > On Wed, Mar 14, 2012 at 6:06 PM, Daniel Farina <dan...@heroku.com> wrote: > > > If we're curious how it affects replication > > traffic, I could probably gather statistics on LZO-compressed WAL > > traffic, of which we have a pretty huge amount captured. > > What's the compression like for shorter chunks of data? Is it worth > considering using this for the libpq copy protocol and therefore > streaming replication also? > > -- > Simon Riggs http://www.2ndQuadrant.com/ > PostgreSQL Development, 24x7 Support, Training & Services
Here is a pointer to some tests with Snappy+CouchDB: https://github.com/fdmanana/couchdb/blob/b8f806e41727ba18ed6143cee31a3242e024ab2c/snappy-couch-tests.txt They checked compression on smaller chunks of data. I have extracted the basic results. The first number is the original size in bytes, followed by the compressed size in bytes, the percent compressed and the compression ratio: 77 -> 60, 90% or 1.1:1 120 -> 104, 87% or 1.15:1 127 -> 80, 63% or 1.6:1 5942 -> 2930, 49% or 2:1 It looks like a good candidate for both the libpq copy protocol and streaming replication. My two cents. Regards, Ken -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
