Rhhh Lin <ruanlinehan@xxxxxxxxxxx> writes: > The EXPLAIN <query> statement is currently 'f' for waiting and 'active' via pg_stat_activity, so it is doing something. The ps command does not show me anything more verbose. ps would confirm for sure whether it was eating CPU time, whereas I do not particularly trust pg_stat_activity to tell you that. > The reason I am very suspect of the timestamp column makeup is that if I > remove that predicate from the EXPLAIN command and the actual query, > both complete within seconds without issue. We've seen issues with the planner having trouble trying to determine the extreme values of an indexed column, in cases where there are a lot of uncommitted or recently-dead entries at the end of the index --- it does a lot of work trying to verify the commit status of each entry in turn. So I wonder if that might apply. regards, tom lane -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
