From: Yinan Li <yinanli@cse.ust.hk>
To: pgsql-performance@postgresql.org
Subject: zero value in statistics collector's result
Date: Mon, 24 Sep 2007 01:00:24 +0800
Message-ID: <003801c7fe03$3c3f8020$b4be8060$@ust.hk> (raw)
Hi,
When I use the statistics collector to see the number of IO, I always get
zero in almost all of columns. I really want to know the reason for that.
The result of statistics view:
# select * from pg_statio_user_tables;
relid | schemaname | relname | heap_blks_read | heap_blks_hit |
idx_blks_read | idx_blks_hit | toast_blks_read | toast_blks_hit |
tidx_blks_read | tidx_blks_hit
-------+------------+---------+----------------+---------------+------------
---+--------------+-----------------+----------------+----------------+-----
----------
16386 | public | tab | 0 | 0 |
0 | 0 | | | |
(1 row)
# select * from pg_statio_user_indexes;
relid | indexrelid | schemaname | relname | indexrelname | idx_blks_read |
idx_blks_hit
-------+------------+------------+---------+--------------+---------------+-
-------------
16386 | 24581 | public | tab | idx_tab_a2 | 0 |
0
(1 row)
I've set:
stats_start_collector = on
stats_row_level = on
stats_block_level = on
and I think that the statistics collector should be running, because:
$ ps aux|grep stats
postgres 3688 0.0 0.0 7272 648 ? Ss 00:48 0:00 postgres:
stats collector process
postgres 29790 0.0 0.0 4004 712 pts/2 S+ 04:44 0:00 grep stats
Any help would be really appreciated.
Regards,
Yinan
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To: pgsql-performance@postgresql.org
Cc: yinanli@cse.ust.hk
Subject: Re: zero value in statistics collector's result
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