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

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?


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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.

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Greg Smith   2ndQuadrant US    greg@2ndQuadrant.com   Baltimore, MD
PostgreSQL Training, Services, and 24x7 Support  www.2ndQuadrant.

My friend, thanks for your replay, however how to prove your view?

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