On Wed, May 17, 2006 at 10:06:04AM +0200, Martijn van Oosterhout wrote: > On Wed, May 17, 2006 at 09:45:35AM +0200, Albe Laurenz wrote: > > Oracle's compression seems to work as follows: > > - At the beginning of each data block, there is a 'lookup table' > > containing frequently used values in table entries (of that block). > > - This lookup table is referenced from within the block. > > Clever idea, pity we can't use it (what's the bet it's patented?). I'd > wager anything beyond simple compression is patented by someone. > > The biggest issue is really that once postgres reads a block from disk > and uncompresses it, this block will be much larger than 8K. Somehow > you have to arrange storage for this.
It's entirely possible that the best performance would be found from not un-compressing blocks when putting them into shared_buffers, though. That would mean you'd "only" have to deal with compression when pulling individual tuples. Simple, right? :) -- Jim C. Nasby, Sr. Engineering Consultant [EMAIL PROTECTED] Pervasive Software http://pervasive.com work: 512-231-6117 vcard: http://jim.nasby.net/pervasive.vcf cell: 512-569-9461 ---------------------------(end of broadcast)--------------------------- TIP 3: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faq
