Re: [PERFORM] pg_statistic doesnt contain details for specific table

2007-06-11 Thread Heikki Linnakangas

Nimesh Satam wrote:

While monitioring we noticed that there are no details in the pg_statistics
for a particular table. Can you let us know what might be the reason? Also
what steps can be taken care for adding the statistics?


Have you ANALYZEd the table?

--
  Heikki Linnakangas
  EnterpriseDB   http://www.enterprisedb.com

---(end of broadcast)---
TIP 9: In versions below 8.0, the planner will ignore your desire to
  choose an index scan if your joining column's datatypes do not
  match


Re: [PERFORM] pg_statistic doesnt contain details for specific table

2007-06-11 Thread Nimesh Satam

Heikki,


Thank you for replying.

We have already used analyze command on the table.
We have also ran the vacuum analyze command.


But they are not helping.

Thanks,
Nimesh.


On 6/11/07, Heikki Linnakangas [EMAIL PROTECTED] wrote:


Nimesh Satam wrote:
 While monitioring we noticed that there are no details in the
pg_statistics
 for a particular table. Can you let us know what might be the reason?
Also
 what steps can be taken care for adding the statistics?

Have you ANALYZEd the table?

--
  Heikki Linnakangas
  EnterpriseDB   http://www.enterprisedb.com



Re: [PERFORM] pg_statistic doesnt contain details for specific table

2007-06-11 Thread Michael Fuhr
On Mon, Jun 11, 2007 at 02:28:32PM +0530, Nimesh Satam wrote:
 We have already used analyze command on the table.
 We have also ran the vacuum analyze command.
 
 But they are not helping.

Is there any data in the table?  What does ANALYZE VERBOSE or VACUUM
ANALYZE VERBOSE show for this table?  Is there any chance that
somebody set all of the columns' statistics targets to zero?

-- 
Michael Fuhr

---(end of broadcast)---
TIP 3: Have you checked our extensive FAQ?

   http://www.postgresql.org/docs/faq


Re: [PERFORM] pg_statistic doesnt contain details for specific table

2007-06-11 Thread Nimesh Satam

Michael,


Following is the output of Vacuum analze on the same table:


*psql =# VACUUM ANALYZE verbose cam_attr;
INFO:  vacuuming public.cam_attr
INFO:  index cam_attr_pk now contains 11829 row versions in 63 pages
DETAIL:  0 index pages have been deleted, 0 are currently reusable.
CPU 0.00s/0.00u sec elapsed 0.00 sec.
INFO:  cam_attr: found 0 removable, 11829 nonremovable row versions in 103
pages
DETAIL:  0 dead row versions cannot be removed yet.
There were 236 unused item pointers.
0 pages are entirely empty.
CPU 0.00s/0.00u sec elapsed 0.00 sec.
INFO:  analyzing public.cam_attr
INFO:  cam_attr: scanned 103 of 103 pages, containing 11829 live rows and
0 dead rows; 6000 rows in sample, 11829 estimated total rows
VACUUM
*

Also how do we check if the statistics are set to Zero for the table?

Regards,
Nimesh.


On 6/11/07, Michael Fuhr [EMAIL PROTECTED] wrote:


On Mon, Jun 11, 2007 at 02:28:32PM +0530, Nimesh Satam wrote:
 We have already used analyze command on the table.
 We have also ran the vacuum analyze command.

 But they are not helping.

Is there any data in the table?  What does ANALYZE VERBOSE or VACUUM
ANALYZE VERBOSE show for this table?  Is there any chance that
somebody set all of the columns' statistics targets to zero?

--
Michael Fuhr



Re: [PERFORM] pg_statistic doesnt contain details for specific table

2007-06-11 Thread Michael Fuhr
On Mon, Jun 11, 2007 at 07:22:24PM +0530, Nimesh Satam wrote:
 INFO:  analyzing public.cam_attr
 INFO:  cam_attr: scanned 103 of 103 pages, containing 11829 live rows and
 0 dead rows; 6000 rows in sample, 11829 estimated total rows

Looks reasonable.

 Also how do we check if the statistics are set to Zero for the table?

SELECT attname, attstattarget
  FROM pg_attribute
 WHERE attrelid = 'public.cam_attr'::regclass
   AND attnum  0
   AND NOT attisdropped;

If nobody has changed the statistics targets then they're all
probably -1.  Negative attstattarget values mean to use the system
default, which you can see with:

SHOW default_statistics_target;

How exactly are you determining that no statistics are showing up
for this table?  Are you running a query like the following?

SELECT *
  FROM pg_stats
 WHERE schemaname = 'public' AND tablename = 'cam_attr';

-- 
Michael Fuhr

---(end of broadcast)---
TIP 2: Don't 'kill -9' the postmaster