Getting Started with IBM Data Studio for DB2

112 Getting Started with IBM Data Studio for DB2
If you have associated any objects with this table space, Data Studio will ask if you want to
drop these impacted objects at the same time. The drop may fail if you choose to not drop
the impacted objects. Unless you want to drop the table space and all of its impacted
objects, you should first alter the impacted objects to disassociate them from the table
space, and then drop the table space.
3.2.2 Creating and managing buffer pools
A buffer pool is the database memory cache that is used to store data and indexes for
faster access. This memory cache is also where the changes made by an application to a
database object are performed, before persisting it to the database. Data is fetched from
the table spaces to this buffer pool for every query before returning the result to the
application. To fetch data from a table space, a buffer pool with the same page size must
exist.
Normally, once the data is fetched into the buffer pool, it remains in the buffer pool until the
buffer pool gets full, in which case the old data is wiped out to make space for the new
data. You can greatly improve performance if you store the data that is required by any
query in the buffer pool, instead of retrieving that data from the disk.
By default, a buffer pool namedIBMDEFAULTBP is created when you create the database.
This default buffer pool is used for all objects unless you explicitly assign the objects to
another buffer pool.
3.2.2.1 Creating a buffer pool
To create a buffer pool:
1. Right-click the Buffer Pools folder and select Create Buffer Pool. The menu is shown in
Figure 3.11.
Figure 3.11 – Creating a new buffer pool