> -----Original Message----- > Zeugswetter Andreas SB > > > As I mentioned already I'm implementing updatable cursors > > in ODBC and have half done it. If OIDs would be optional > > my trial loses its validity but I would never try another > > implementation. > > But how can you do that ? The oid index is only created by > the dba for specific tables, thus your update would do an update > with a where restriction, that is not indexed. > This would be darn slow, no ? >
Please look at my another(previous ?) posting to pgsql-hackers. I would use both TIDs and OIDs, TIDs for fast access, OIDs for identification. > How about instead selecting the primary key and one of the tid's > (I never remember which, was it ctid ?) instead, so you can validate > when a row changed between the select and the update ? > Xmin is also available for row-versioning. But now I'm wondering if TID/xmin are guranteed to keep such characteriscs. Even Object IDentifier is about to lose the existence. Probably all-purpose application mustn't use system columns at all though I've never heard of it in other dbms-s. regards, Hiroshi Inoue ---------------------------(end of broadcast)--------------------------- TIP 4: Don't 'kill -9' the postmaster
