?? 2014/7/25 9:53, Tom Lane ????:
[ shrug... ] Insufficient data. When I try a simple test case based on what you've told us, I get planning times of a couple of milliseconds. I can think of contributing factors that would increase that, but not by four orders of magnitude. So there's something very significant that you've left out. Can you construct a self-contained test case that's this slow? regards, tom lane
I run dbg on the backend process and got this: (gdb) bt #0 0x00007fc4a1b6cdb7 in semop () from /lib/x86_64-linux-gnu/libc.so.6 #1 0x00000000005f8703 in PGSemaphoreLock () #2 0x0000000000636703 in LWLockAcquire () #3 0x0000000000632eb3 in LockAcquireExtended () #4 0x000000000062fdfb in LockRelationOid () #5 0x0000000000474e55 in relation_open () #6 0x000000000047b39b in index_open () #7 0x00000000005f3c22 in get_relation_info () #8 0x00000000005f6590 in build_simple_rel () #9 0x00000000005f65db in build_simple_rel () #10 0x00000000005de8c0 in add_base_rels_to_query () #11 0x00000000005df352 in query_planner () #12 0x00000000005e0d51 in grouping_planner () #13 0x00000000005e2bbe in subquery_planner () #14 0x00000000005e2ef9 in standard_planner () #15 0x00000000006426e1 in pg_plan_query () #16 0x000000000064279e in pg_plan_queries () #17 0x00000000006f4b7a in BuildCachedPlan () #18 0x00000000006f4e1e in GetCachedPlan () #19 0x0000000000642259 in exec_bind_message () #20 0x0000000000643561 in PostgresMain () #21 0x000000000060347f in ServerLoop () #22 0x0000000000604121 in PostmasterMain () #23 0x00000000005a5ade in main () Does that indicate something? seems it's waiting for some lock. -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance