I have some simple query (executed with time command):
time psql -c 'explain analyze SELECT te.idt FROM t_positions AS te JOIN
t_st AS stm ON (te.idt=stm.idt AND 4=stm.idm) WHERE te.idtr IN (347186)'
QUERY
=?iso-8859-2?Q?Artur_Zaj=B1c?= aza...@ang.com.pl writes:
Why there is so big difference between explain analyze (0.710 ms) and real
execution time (3309 ms)?
EXPLAIN ANALYZE doesn't account for all of the runtime involved. In
this case, I'd bet that session startup/shutdown is a big part of
EXPLAIN ANALYZE doesn't account for all of the runtime involved. In this
case, I'd bet that session startup/shutdown is a big part of the difference.
regards, tom lane
Does session startup/shutdown depend on tables used in query? Some simpler
query:
time psql -c
[Tom Lane]
EXPLAIN ANALYZE doesn't account for all of the runtime involved. In
this case, I'd bet that session startup/shutdown is a big part of the
difference.
The session startup/shutdown should be the same for the real SQL and
the broken SQL, shouldn't it?
[Artur Zając]
time psql -c
2010/11/15 Artur Zając aza...@ang.com.pl:
Why there is so big difference between explain analyze (0.710 ms) and real
execution time (3309 ms)? Any suggestions?
Could it be that it takes a long time to plan for some reason? How
fast is a plain EXPLAIN?
What happens if you start up psql, turn
2010/11/15 Artur Zając aza...@ang.com.pl:
Why there is so big difference between explain analyze (0.710 ms) and
real execution time (3309 ms)? Any suggestions?
Could it be that it takes a long time to plan for some reason? How fast
is a plain EXPLAIN?
Yes! That is it :) Planning is
=?iso-8859-2?Q?Artur_Zaj=B1c?= aza...@ang.com.pl writes:
I've changed default_statistics_target to 1 and I think that is a
reason.
That's certainly going to cost you something, but this seems like a
mighty large slowdown, especially for a non-join query. What datatype
is te.idtr, anyway?
I've changed default_statistics_target to 1 and I think that is a
reason.
That's certainly going to cost you something, but this seems like a mighty
large slowdown, especially for a non-join query. What datatype is te.idtr,
anyway?
Integer not null and primary key of t_positions
