On Mon, Aug 11, 2014 at 01:44:05PM -0700, Peter Geoghegan wrote: > On Mon, Aug 11, 2014 at 1:01 PM, Stephen Frost <sfr...@snowman.net> wrote: > > We've got a clear example of someone, quite reasonably, expecting their > > JSONB object to be compressed using the normal TOAST mechanism, and > > we're failing to do that in cases where it's actually a win to do so. > > That's the focus of this discussion and what needs to be addressed > > before 9.4 goes out. > > Sure. I'm not trying to minimize that. We should fix it, certainly. > However, it does bear considering that JSON data, with each document > stored in a row is not an effective target for TOAST compression in > general, even as text.
Seems we have two issues: 1) the header makes testing for compression likely to fail 2) use of pointers rather than offsets reduces compression potential I understand we are focusing on #1, but how much does compression reduce the storage size with and without #2? Seems we need to know that answer before deciding if it is worth reducing the ability to do fast lookups with #2. -- Bruce Momjian <br...@momjian.us> http://momjian.us EnterpriseDB http://enterprisedb.com + Everyone has their own god. + -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
