Scott Ribe <scott_ribe@xxxxxxxxxxxxxxx> writes: >> So it works right now, except it doesn't have (yet) the infrastructure to >> keep the scans synchronized > Perhaps you only got one read of the table because the process is > essentially self-synchronizing. Right. Multiple seqscans that are anywhere near reading the same block of a table will tend to self-synchronize. There is a patch under consideration for 8.3 that helps this along by making seqscans run "circularly" --- that is, not always from block 0 to block N, but from block M to N and then 0 to M-1, where the start point M can be chosen by looking to see where any other concurrent seqscan is presently reading. Once you've got a reasonable start point, you don't have to do anything else. regards, tom lane
