How to load a table to bufferpool when system start?

dejunzhu · Active User Joined: 08 May 2008 Posts: 390 Location: China

to decrease the time application spends on DB2 connection, I want to load a table to bufferpool at the point when system start, so that data fetch processing can become more faster for application.

Can I achieve this? and how?

Thanks.

dick scherrer · Posted: Thu Mar 22, 2012 10:53 am

Hello,

So run a process that reads the table. . .

Realizing that this will probably not accomplish what you want.

dejunzhu · Active User Joined: 08 May 2008 Posts: 390 Location: China

hi, dick,
thanks for your recommendation.

but can you tell me why " this will probably not accomplish what you want." ?

thanks.

enrico-sorichetti · Posted: Thu Mar 22, 2012 6:12 pm

the why can be found in the db2 manuals where it talks about buffer pool

POOL is the buzzword, the thing is not something dedicated to a single table,
is a dynamic container for all the tables/databases with the same buffer size
where the LRU buffers are flushed to satisfy new requests

dick scherrer · Posted: Fri Mar 23, 2012 6:17 am

Hello,

Also, when the table is read the first time by some query, it will be loaded into the "bufferpool". No "special" load is needed.

If there are no requests that cause the pool to be flushed, the info will still be "in core". As Enrico mentoned, new requests can cause the oldest in-core "stuff" to be flushed - which is how a database system should work.

If the table in queston is "hit" by most transactons, much of the data will remain in core. If this is seldom used, it will be flushed with regularity.

dejunzhu · Active User Joined: 08 May 2008 Posts: 390 Location: China

okay ,I got it.

as the table is most frequently used, I suppose it will not be paged out provided there is large enough pool size.