pg_stats not getting updated....

wht i wanted to do is... identify the tables which are getting used simultaneously... so that i can move them to different tablespaces....

 

for that i tried to do sampling of "pg_statio_user_tables" for top 20 tables...(in terms of usage)... so that i know how much io is being done... for different tables and when....

 

now the problem is... pg_statio_user_tables is not getting updated... at least wht i am able to make out of documentation is they should be updated regularly at each commit... but i am doing lots of commits in my test application....

 

also docs state that withing each transaction block postgres tries to give the same stats.... forget abt transaction blocks.. i even tried.. disconnecting and then reconnecting my sampling application every two mins... but no use... each time i am getting same stats...(only 4 updates in 30mins).....

 

one more thing that i noted is each time i run analyze.... pg_statio_user_tables is updated....

 

plz note that all pg_stat* tables are not getting updated not just pg_statio*....

i posted in general mailing list but no satisfying reply so i thought maybe u all can tell whts happening......

 

thx

Himanshu