Tom Lane wrote: > Hannu Krosing <[EMAIL PROTECTED]> writes: > > But if we would allow the scans to find the same keys twice without ill > > effects (as was suggested earlier, for using btrees to index arrays), > > How is returning the same data twice not an "ill effect"? > > > then we could possibly 1) copy the key to the right 2) wait for all > > right-to-left scans that have fallen between old and new values to pass > > and only then 3) delete the "old left" key. > > How will you wait for scans that you know nothing of to go past? > Especially when they are going to be blocked by your own write lock > on the left page?
I think we should skip any pages where we can't get a lock. -- Bruce Momjian | http://candle.pha.pa.us [EMAIL PROTECTED] | (610) 359-1001 + If your life is a hard drive, | 13 Roberts Road + Christ can be your backup. | Newtown Square, Pennsylvania 19073 ---------------------------(end of broadcast)--------------------------- TIP 4: Don't 'kill -9' the postmaster
