On Fri, Jul 17, 2009 at 9:21 PM, Kevin Grittner<kevin.gritt...@wicourts.gov> wrote: > "Joshua D. Drake" <j...@commandprompt.com> wrote: >> On Fri, 2009-07-17 at 12:50 -0500, Kevin Grittner wrote: > >>> (3) Allow override of the thresholds for individual columns. > >> I would skip 1 and 2 and have (3). > > Sure, pick the one which requires new syntax! ;-) > > How about two new ALTER TABLE actions: > > ALTER [ COLUMN ] column SET COMPRESSION_THRESHOLD integer > ALTER [ COLUMN ] column SET EXTERNAL_THRESHOLD integer > > Or can you suggest something better? > > Laurent, would something like this address your needs? I was assuming > that if the point is to reduce I/O, you were interested in doing more > compression, not in storing more values out-of-line (in the separate > TOAST table)? Would it be manageable to tune this on a column-by- > column basis?
Certainly ! We already alter storage type on some column, adding some more won't be a problem. :) But... on which version are you planning to do that ? We're still using Postgresql 8.3, because we use Slony-1 1.2.15 and upgrading to 8.4 is a *major* pain (discussed on slony mailling list). Slony-1 1.2.15 won't compile on 8.4, and upgrading to Slony-1 2.0.x require to rebuild the whole cluster (and upgrading to Pg 8.4 require a rebuild too). So we'd need to upgrade both slony and postgresql with an impossible downtime :) We stay on Pg 8.3 until the slony developpers find a better upgrade solution. The proposed solution sound really good to me. But, for now, if i could have a simple patch for 8.3 (eg: changing a #define in the source code), i'd be very happy :) Is it ok to just change TOAST_TUPLES_PER_PAGE ? Thank you for all your replies and proposed solutions :) PS : i'm not a C coder, but if you know some perl to be patched/cleaned, i'm here :) -- Laurent Laborde Sysadmin at http://www.over-blog.com/ -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
