Index counters of statistics collector does not work on 7.4devel
Fields idx_scan and idx_tup_fetch are not changed by an index scan.
=# create table class1 (id integer);
CREATE TABLE
=#
-- Insert 0..9999 into class1
=# create index class1_id_index on class1 (id);
CREATE INDEX
=# vacuum analyze;
VACUUM
=# \x
Expanded display is on.
=# select * from pg_stat_all_tables where relname = 'class1';
-[ RECORD 1 ]-+-------
relid | 17166
schemaname | public
relname | class1
seq_scan | 2
seq_tup_read | 13000
idx_scan | 0
idx_tup_fetch | 0
n_tup_ins | 10000
n_tup_upd | 0
n_tup_del | 0
=# \x
Expanded display is off.
=# explain select * from class1 where id = 1234;
QUERY PLAN
------------------------------------------------------------------------------
Index Scan using class1_id_index on class1 (cost=0.00..3.01 rows=2 width=4)
Index Cond: (id = 1234)
(2 rows)
=# \x
Expanded display is on.
=# select * from pg_stat_all_tables where relname = 'class1';
-[ RECORD 1 ]-+-------
relid | 17166
schemaname | public
relname | class1
seq_scan | 2
seq_tup_read | 13000
idx_scan | 0
idx_tup_fetch | 0
n_tup_ins | 10000
n_tup_upd | 0
n_tup_del | 0
=#
Kenji Sugita
"Kenji Sugita" <sugita@srapc1327.sra.co.jp> wrote:
=# explain select * from class1 where id = 1234;
QUERY PLAN
----------------------------------------------------------------------
--------
Index Scan using class1_id_index on class1 (cost=0.00..3.01 rows=2
width=4)
Index Cond: (id = 1234)
(2 rows)
I don't think that the select is really performed, try the same experiment
but doing
explain analyze instead.
Regards
Gaetano Mendola
From: "Mendola Gaetano" <mendola@bigfoot.com>
Subject: Re: [HACKERS] Index counters of statistics collector does not work on 7.4devel
Date: Sun, 20 Jul 2003 15:42:29 +0200
;;; "Kenji Sugita" <sugita@srapc1327.sra.co.jp> wrote:
;;; > =# explain select * from class1 where id = 1234;
;;; > QUERY PLAN
;;; > ----------------------------------------------------------------------
;;; --------
;;; > Index Scan using class1_id_index on class1 (cost=0.00..3.01 rows=2
;;; width=4)
;;; > Index Cond: (id = 1234)
;;; > (2 rows)
;;;
;;; I don't think that the select is really performed, try the same experiment
;;; but doing
;;; explain analyze instead.
I forgot to include a select without explain. I found it July 15. Anyway it
works for today's version.
Kenji Sugita