Re: Whether the function exists a in pgsql table or not?

On 08/27/2011 01:21 PM, shuaixf wrote:
> In Oracle, when the table has few records, used frequently, it would use
> "storage(buffer_pool keep)" to keep the data in cache instead of LRU
> algorithm.
>
> if the function exists in a pgsql table or not?
>

There aren't any controls to pin a table into memory in PostgreSQL. The
way the database uses both its dedicated buffer cache as well as the OS
one, it's hard to even define such a UI that would make sense--the
database doesn't have any control or interaction with the OS cache.

The mechanism for deciding what stays in the PostgreSQL cache is a bit
more complicated than an LRU, while the one in the OS probably is a
LRU. If the table is used frequently, it's very likely to stay in one
of the two caches anyway.

--
Greg Smith 2ndQuadrant US greg(at)2ndQuadrant(dot)com Baltimore, MD
PostgreSQL Training, Services, and 24x7 Support www.2ndQuadrant.