Configuring the block-based area
Buffer pools are defined as having a large number of pages by default, so when DB2 issues a prefetch, the pages read from the disk may not be stored contiguously in the buffer pool.
The block-based area enhances prefetching performance by allowing a contiguous area of the buffer pool for this eventuality, named the block area, or block-based area. Each set of contiguous pages is called a block; the number of pages in a block is referred to as the blocksize.
Getting ready
Make sure the application uses sequential prefetching; otherwise the block area of the block buffer is useless. Allow a time frame for a possible database restart.
How to do it...
Get the database configuration:
[db2inst1@nodedb21 ~]$ db2 get db cfg Database Configuration for Database
We'll be looking for parameters related to prefetching.
Default prefetch size (pages) (DFT_PREFETCH_SZ) = AUTOMATIC Default table space extentsize (pages) (DFT_EXTENT_SZ) = 32
Get current characteristics...