* Ashutosh Bapat (ashutosh.bapat@enterprisedb.com) wrote:
> >> One can use this option as
> >> postgres=# explain (summary on) select * from pg_class c, pg_type t
> >> where c.reltype = t.oid;
> >> QUERY PLAN
> >> --------------------------------------------------------------------------
> >> Hash Join (cost=17.12..35.70 rows=319 width=511)
> >> Hash Cond: (c.reltype = t.oid)
> >> -> Seq Scan on pg_class c (cost=0.00..14.19 rows=319 width=259)
> >> -> Hash (cost=12.61..12.61 rows=361 width=256)
> >> -> Seq Scan on pg_type t (cost=0.00..12.61 rows=361 width=256)
> >> Planning time: 48.823 ms
> >> (6 rows)
> >>
> >> When analyze is specified, summary is also set to ON. By default this
> >> flag is OFF.
> >>
> >
> > I am not sure whether using *summary* to print just planning time is a
> > good idea. Another option could be SUMMARY_PLAN_TIME.
>
> I have just used the same name as the boolean which controls the
> printing of planning time. Suggestions are welcome though. We haven't
> used words with "_" for EXPLAIN options, so I am not sure about
> SUMMARY_PLAN_TIME.
Using 'summary' seems entirely reasonable to me, I don't think we need
to complicate it by saying 'summary_plan_time'- I know that I'd had to
have to write that out.
> > + /* Execution time matters only when analyze is requested */
> > + if (es->summary && es->analyze)
> >
> > Do you really need es->summary in above check?
I'm pretty sure we do.
EXPLAIN (ANALYZE, SUMMARY OFF)
Should not print the summary (which means it shouldn't print either the
planning or execution time).
> I think es->summary controls printing overall timing, planning as well
> as execution (hence probably the name "summary").
I am imagining it controlling if we print the summary or not, where the
summary today is the last two lines:
Planning time: 14.020 msExecution time: 79.555 ms
Thanks!
Stephen