> > Af far as I know Oracle doesn't have any short cut (along the lines of > > what is being discussed in this thread) for this operation. However > > Oracle is more efficient in providing the answer than postgres > currently > > is. While postgres needs to perform a full scan on the table, Oracle > > will only need to perform a full index scan on the primary key if one > > exists. Since the index will likely have much less data than the full > > Under Postgres, a full index scan is generally more expensive than a full > table scan since indices, particularly btree, carry a large amount of meta > data and theefore consume more pages.
Don't forget that Postgres also doesn't store tids in the index, so must always check with the main table that a row is visible in current transaction. Chris ---------------------------(end of broadcast)--------------------------- TIP 2: you can get off all lists at once with the unregister command (send "unregister YourEmailAddressHere" to [EMAIL PROTECTED])