pg_class : reltuples
What does "reltuples" from pg_class represent?
any comments
Here is something that raised this question:
---------------------------------------
testdb=# select count(*) from zuser3;
count
---------
1000000
(1 row)
testdb=# select count(*) from zuser2;
count
--------
100000
(1 row)
testdb=# select count(*) from zuser1;
count
-------
1000select relname,relpages,reltuples from pg_class where relname like
'zuse%';
relname | relpages | reltuples
---------+----------+-----------
zuser2 | 10 | 1000
zuser1 | 10 | 1000
zuser3 | 10 | 1000
(3 rows)
(1 row)
Sandeep Joshi <sjoshi@Zambeel.com> writes:
I had to run "vacuum" to get corect no.s. Why is that? I thought
"pg_class" will be upto date.
reltuples and relpages are just updated by vacuum (and maybe create
index). They're not intended to be accurate values, only approximate
statistics.
regards, tom lane
Import Notes
Reply to msg id not found: 3A1C2AAB.B1567EA4@zambeel.com
I had to run "vacuum" to get corect no.s. Why is that? I thought
"pg_class" will be upto date.
This makes me nervous.
Sandeep
Show quoted text
What does "reltuples" from pg_class represent?
any comments
Here is something that raised this question:---------------------------------------
testdb=# select count(*) from zuser3;
count
---------
1000000
(1 row)testdb=# select count(*) from zuser2;
count
--------
100000
(1 row)testdb=# select count(*) from zuser1;
count
-------
1000
select relname,relpages,reltuples from pg_class where relname like
'zuse%';
relname | relpages | reltuples
---------+----------+-----------
zuser2 | 10 | 1000
zuser1 | 10 | 1000
zuser3 | 10 | 1000
(3 rows)(1 row)