On Thu, Jun 08, 2006 at 11:55:02AM -0400, Tom Lane wrote: > "Jim C. Nasby" <jnasby@xxxxxxxxxxxxx> writes: > > On Thu, Jun 08, 2006 at 11:18:02AM +0200, Ludek Finstrle wrote: > >> I read this value in TOAST section. Is my opinion correct? > > > From http://www.postgresql.org/docs/8.1/interactive/storage-toast.html: > > "TOAST usurps the high-order two bits of the varlena length word, > > thereby limiting the logical size of any value of a TOAST-able data type > > to 1Gb (2^30 - 1 bytes)." > > > There was a proposal made some time ago to allow for a variable-length > > length word format, where one of the bits in each word would specify > > that there was an additional length word. > > Hm, I don't remember that. It seems rather pointless, as I'm quite sure > that the *practical* limit is a great deal less than 1Gb. Has anyone > done any performance testing of GB-sized toasted values? Given how toasted data is currently stored, you're probably correct. If it was switched to a binary format that didn't have all the table/tuple overheard (which I seem to recall a discussion about), it could be a very different story. -- Jim C. Nasby, Sr. Engineering Consultant jnasby@xxxxxxxxxxxxx Pervasive Software http://pervasive.com work: 512-231-6117 vcard: http://jim.nasby.net/pervasive.vcf cell: 512-569-9461
