On 2013-01-07 09:57:58 +0000, Simon Riggs wrote: > On 7 January 2013 09:19, John R Pierce <pie...@hogranch.com> wrote: > > On 1/7/2013 1:10 AM, Simon Riggs wrote: > >> > >> On 7 January 2013 07:29, Takeshi Yamamuro > >> <yamamuro.take...@lab.ntt.co.jp> wrote: > >> > >>> >Anyway, the compression speed in lz4 is very fast, so in my > >>> >opinion, there is a room to improve the current implementation > >>> >in pg_lzcompress. > >> > >> So why don't we use LZ4? > > > > what will changing compression formats do for compatability? > > > > this is for the compressed data in pg_toast storage or something? will this > > break pg_upgrade style operations? > > Anything that changes on-disk format would need to consider how to do > pg_upgrade. It's the major blocker in that area. > > For this, it would be possible to have a new format and old format > coexist, but that will take more time to think through than we have > for this release, so this is a nice idea for further investigation in > 9.4. Thanks for raising that point.
I think there should be enough bits available in the toast pointer to indicate the type of compression. I seem to remember somebody even posting a patch to that effect? I agree that it's probably too late in the 9.3 cycle to start with this. Greetings, Andres Freund -- Andres Freund http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
