Re: Very slow planning performance on partition table

在 2014/7/25 9:53, Tom Lane 写道:
> [ 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.