Bruce Momjian wrote:
Looking at the patch I see:Advertising
+ /* + * Mark the page as clear of prunable tuples. If we find a tuple which + * may become prunable, we shall set the hint again. + */ + PageClearPrunable(page); I like the idea of the page hint bit, but my question is if there is a long-running transaction, isn't each SELECT going to try to defragment a page over and over again because there is still something prunable on the page?
Maybe that risk could be lowered if instead of a flag, we stored the minimal global xmin needed to prune at least one tuple. greetings, Florian Pflug ---------------------------(end of broadcast)--------------------------- TIP 2: Don't 'kill -9' the postmaster
