Обсуждение: Buffers option

I'm trying to anlayze a query in postgresql v9.6.4: explain (ANALYZE,BUFFERS) SELECT p.* FROM place as p INNER JOIN user as u ON p.id = u.place_id where to_tsvector('simple', p.name) @@ to_tsquery('simple', 'a:*') and u.status = true; The QueryPlan was : Hash Join (cost=20.28..31.72 rows=1 width=1561) (actual time=0.001..0.001 rows=0 loops=1)' Hash Cond: (u.place_id = p.id)' -> Seq Scan on user u (cost=0.00..11.20 rows=60 width=4) (actual time=0.001..0.001 rows=0 loops=1)' Filter: status' -> Hash (cost=20.27..20.27 rows=1 width=1561) (never executed)' -> Bitmap Heap Scan on place p (cost=16.01..20.27 rows=1 width=1561) (never executed)' Recheck Cond: (to_tsvector('simple'::regconfig, (name)::text) @@ '''a'':*'::tsquery)' -> Bitmap Index Scan on place_name_index(cost=0.00..16.01 rows=1 width=0) (never executed)' Index Cond: (to_tsvector('simple'::regconfig, (name)::text) @@ '''a'':*'::tsquery)' Planning time: 0.118 ms Execution time: 0.023 ms I didn't get the number of read and hit buffers when I rexecute the query many times.How can I Fix that? and I tried the options costs, timing and I got the same plan query however when trying the option format json it works.

On Fri, Nov 24, 2017 at 12:30 PM, hmidi slim <hmidi.slim2@gmail.com> wrote:
> I didn't get the number of read and hit buffers when I rexecute the query
> many times.How can I Fix that? and I tried the options costs, timing and I
> got the same plan query however when trying the option format json it works.


Not sure but I see a lot of nodes 'never executed' and 'rows=0' on the
first loop. Could it be the optimzer did not execute nothing at all?

Luca

with this query: explain (ANALYZE,BUFFERS) SELECT p.*FROM place as p, user as u where p.id = u.place_id and to_tsvector('simple', p.name) @@ to_tsquery('simple', 'a:*') and u.status = true; I got the buffers.I think that is not working with JOIN INNER. 2017-11-24 13:46 GMT+01:00 Luca Ferrari : > On Fri, Nov 24, 2017 at 12:30 PM, hmidi slim > wrote: > > I didn't get the number of read and hit buffers when I rexecute the query > > many times.How can I Fix that? and I tried the options costs, timing and > I > > got the same plan query however when trying the option format json it > works. > > > Not sure but I see a lot of nodes 'never executed' and 'rows=0' on the > first loop. Could it be the optimzer did not execute nothing at all? > > Luca >