[GENERAL] PG Stats Collector

[Arvind Singh]

Hello and greetings,
 
I need help in understanding the purpose of the following columns produced by 
PG stats collector in version 9.1
 
>From  pg_stat_database
-----------------------------
blks_read,
blks_hit,
_tup_returned,
tup_fetched
 
Reported In pg_stat_user_tables
-------------------------------------
idx_tup_fetch,
n_tup_hot_upd,
n_live_tup,
n_dead_tup
 
 
thank you,
arvind