On Tue, May 13, 2014 at 06:58:11PM -0400, Tom Lane wrote: > A recent question from Tim Kane prompted me to measure the overhead > costs of EXPLAIN ANALYZE, which I'd not checked in awhile. Things > are far worse than I thought. On my current server (by no means > lavish hardware: Xeon E5-2609 @2.40GHz) a simple seqscan can run > at something like 110 nsec per row:
I assume you ran pg_test_timing too: Testing timing overhead for 3 seconds. Per loop time including overhead: 41.70 nsec Histogram of timing durations: < usec % of total count 1 95.83035 68935459 2 4.16923 2999133 4 0.00037 268 8 0.00004 31 16 0.00000 1 32 0.00000 1 My overhead of 41.70 nsec matches yours. -- Bruce Momjian <br...@momjian.us> http://momjian.us EnterpriseDB http://enterprisedb.com + Everyone has their own god. + -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers