Tom Lane wrote: > Scott Marlowe <smarlowe@xxxxxxxxxxxxxxxxx> writes: > > On Mon, 2006-12-11 at 10:18, Jonathan Ellis wrote: > >> I have a table of log messages. They are mostly in the 100-200 > >> character length, which apparently isn't large enough for PG to want > >> to compress it (length == octet_length). I really need to save disk > >> space. I can store it as a bytea and compress it manually (zlib level > >> 1 compression gives about 50% savings), but is there a way to force > >> pg's own compression before I resort to this? > > > http://www.postgresql.org/docs/8.1/interactive/storage-toast.html > > Has all your answers. > > The bottom line is that PG doesn't bother trying to compress values > less than about 2KB long. While you could make a custom build with a > different threshold, the fact remains that LZ-style compression is not > real efficient on short stretches of text. If you "really need to save > disk space" it behooves you to consider that. I'd suggest thinking about > whether you can merge multiple log entries, or something, such that the > field values you need to store are on the order of a few KB. See ALTER TABLE ALTER [ COLUMN ] column SET STORAGE { PLAIN | EXTERNAL | EXTENDED | MAIN }. -- Bruce Momjian bruce@xxxxxxxxxx EnterpriseDB http://www.enterprisedb.com + If your life is a hard drive, Christ can be your backup. +
