On 2014-09-11 13:04:43 -0400, Robert Haas wrote: > On Thu, Sep 11, 2014 at 12:58 PM, Andres Freund <and...@2ndquadrant.com> > wrote: > > On 2014-09-11 12:55:21 -0400, Robert Haas wrote: > >> I advise supporting pglz only for the initial patch, and adding > >> support for the others later if it seems worthwhile. The approach > >> seems to work well enough with pglz that it's worth doing even if we > >> never add the other algorithms. > > > > That approach is fine with me. Note though that I am pretty strongly > > against adding support for more than one algorithm at the same time. > > What if one algorithm compresses better and the other algorithm uses > less CPU time?
Then we make a choice for our users. A configuration option about an aspect of postgres that darned view people will understand with for the marginal differences between snappy and lz4 doesn't make sense. > I don't see a compelling need for an option if we get a new algorithm > that strictly dominates what we've already got in all parameters, and > it may well be that, as respects pglz, that's achievable. But ISTM > that it need not be true in general. If you look at the results lz4 is pretty much there. Sure, there's algorithms which have a much better compression - but the time overhead is so large it just doesn't make sense for full page compression. Greetings, Andres Freund -- Andres Freund http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (firstname.lastname@example.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers