I trawled through the first, larger dump you sent me, and found multiple index entries pointing to quite a few heap tuples:
Occurrences block item 2 43961 1 2 43961 2 2 43961 3 2 43961 4 2 43961 5 2 43961 6 2 43961 7 2 43961 8 2 43961 9 2 119695 1 2 119695 2 2 119695 3 2 126029 1 2 126029 2 2 126029 3 2 166694 1 2 166865 1 2 166865 2 2 166865 3 2 166865 4 2 166865 5 2 166865 6 2 166865 7 2 206221 1 2 247123 1 2 327775 1 2 327775 2 2 327775 3 2 327775 4 2 327775 5 2 327775 6 2 327775 7 2 327775 8 2 327775 9 2 327775 10 2 327775 11 Both indexes show identical sets of duplicates, which makes it pretty hard to credit that it's a within-index problem. You mentioned that the test had been allowed to run for a good while after the first slave error was noted. So it seems there's no question that we are looking at some mechanism that allows the first few entries on a heap page to be lost and overwritten :-(, and that this happened several times over the course of the larger run. regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 2: Don't 'kill -9' the postmaster