On Thu, Dec 01, 2005 at 07:18:10PM -0800, Uwe C. Schroeder wrote: > Why not have something like the rowid in oracle?
http://www.postgresql.org/docs/8.1/interactive/datatype-oid.html, search on ctid. And http://www.postgresql.org/docs/8.1/interactive/ddl-system-columns.html. >From the 2nd URL: ctid The physical location of the row version within its table. Note that although the ctid can be used to locate the row version very quickly, a row's ctid will change each time it is updated or moved by VACUUM FULL. Therefore ctid is useless as a long-term row identifier. The OID, or even better a user-defined serial number, should be used to identify logical rows. Though I think that a lazy vacuum can change (well, technically remove) a ctid. AFAIK, it's not safe to use a ctid outside of the transaction you got it in. Though come to think about it, I don't think there's any way to get the ctid of a row you just inserted anyway... Maybe the docs should be changed to just say that you should never reuse a ctid outside of the transaction you obtained the ctid in? -- 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 4: Have you searched our list archives? http://archives.postgresql.org
