Hello!
I am newbie in Postgres, but previously worked with Oracle. Now I am puzzled with heap_blks_hit/heap_blks_read ratio. I make select from table (whose size is larger than shared_buffer) and saw that it was wholly read from disk after second, third and so on runs. Isn't is wrong that RDBMS tries to cache table data blocks at least PARTIALLY in the case of insufficient cache buffer?
WBW&R, Grigory Titov.