On Mon, Aug 6, 2018 at 7:42 PM Tom Lane <tgl@xxxxxxxxxxxxx> wrote:
Ken Tanzer <ken.tanzer@xxxxxxxxx> writes:
> Hi Adrian. Happy to provide this info. Though on a side note, I don't
> understand why it should matter, if functions are black box optimization
> fences.
They aren't, at least not when they are SQL-language functions that
meet the conditions for inlining.
Yeah, I kinda realized after I sent this that I wasn't really making much sense. :) I appreciate your explanation though.
The reason that EXPLAIN VERBOSE
is helpful here is that you can see whether the function got inlined
or not: do you see a call to the function, or a representation of
its body?
I wasn't able to get anything more VERBOSE than what I sent before. I re-copied it below. (If there's another command or option I should be using, please advise.)
There is the difference in the two output lines, which I guess suggests that the stable one got inlined and the immutable one didn't?
Output: client_id, si_imm(client_id)
Output: client_id, staff_inspector_stable(client_id, target_date())
spc=> EXPLAIN (ANALYZE,BUFFERS,VERBOSE) SELECT client_id,si_imm(client_id) FROM tbl_residence_own;
QUERY PLAN
-------------------------------------------------------------------------------------------------------------------------------
Seq Scan on public.tbl_residence_own (cost=0.00..1990.02 rows=6977 width=8) (actual time=3.771..22665.604 rows=6983 loops=1)
Output: client_id, si_imm(client_id)
Buffers: shared hit=199814
Planning time: 0.156 ms
Execution time: 22677.333 ms
(5 rows)
spc=> EXPLAIN (ANALYZE,BUFFERS,VERBOSE) SELECT client_id,si_stable(client_id) FROM tbl_residence_own;
QUERY PLAN
------------------------------------------------------------------------------------------------------------------------------
Seq Scan on public.tbl_residence_own (cost=0.00..3734.27 rows=6977 width=8) (actual time=3.100..1302.888 rows=6983 loops=1)
Output: client_id, staff_inspector_stable(client_id, target_date())
Buffers: shared hit=60174
Planning time: 0.354 ms
Execution time: 1315.746 ms
(5 rows)Cheers,Ken
AGENCY Software
A Free Software data system
By and for non-profits
(253) 245-3801
learn more about AGENCY or
follow the discussion.
