index stat

PostgreSQL:8.2.4

I am collecting statistics info now on my database.  I have used the following two queries:

select * from pg_stat_all_indexes;

select * from pg_statio_all_indexes;

How can I use the information from these two queries to better optimize my indexes?  Or maybe even get rid of some unnecessary indexes.

Example output:

  relid  | indexrelid |  schemaname   |        relname        |           indexrelname            | idx_blks_read | idx_blks_hit

---------+------------+---------------+-----------------------+-----------------------------------+---------------+--------------

   16801 |      57855 | a                 | screen                | screen_index1                     |          1088 |       213618

   16801 |      57857 | a                 | screen                | screen_index3                     |           905 |       201219

   16803 |      16805 | pg_toast      | pg_toast_16801        | pg_toast_16801_index              |          3879 |      1387471

   16978 |      16980 | pg_toast      | pg_toast_16976        | pg_toast_16976_index              |             0 |            0

  942806 |     942822 | b                | question_result_entry | question_result_entry_index1      |            18 |            0

  942806 |     942824 | b                | question_result_entry | question_result_entry_index2      |            18 |            0

  942806 |     942828 | b                | question_result_entry | question_result_entry_index3      |            18 |            0

  relid  | indexrelid |  schemaname   |        relname        |           indexrelname            | idx_scan  | idx_tup_read | idx_tup_fetch

---------+------------+---------------+-----------------------+-----------------------------------+-----------+--------------+---------------

   16801 |      57855 | a                    | screen                      | screen_index1                           |     48693 |      1961745 |       1899027

   16801 |      57857 | a                    | screen                      | screen_index3                           |     13192 |       132214 |         87665

   16803 |      16805 | pg_toast         | pg_toast_16801        | pg_toast_16801_index              |    674183 |       887962 |        887962

   16978 |      16980 | pg_toast         | pg_toast_16976        | pg_toast_16976_index              |         0 |            0 |             0

 942806 |     942822 | b                    | question_result_entry | question_result_entry_index1    |         0 |            0 |             0      

 942806 |     942824 | b                    | question_result_entry | question_result_entry_index2    |         0 |            0 |             0

 942806 |     942828 | b                    | question_result_entry | question_result_entry_index3    |         0 |            0 |             0

Thanks,

Lance Campbell

Project Manager/Software Architect

Web Services at Public Affairs

University of Illinois

217.333.0382

http://webservices.uiuc.edu