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Guidelines for Setting Up IBM DB2 Buffer Pools

A buffer pool is an area of main system memory that is used for holding pages of data that have been fetched from the tablespace. In IBM DB2, each tablespace is associated with a buffer pool. Adding more space to a buffer pool enhances the performance of the database.

You must have at least three buffer pools for the Siebel tablespaces. You can use the default buffer pool to buffer data pages from all of the Siebel 4-KB tablespaces.

You must also create additional buffer pools with 16-KB and 32-KB page sizes for sorting and other SQL processing. A sample configuration is shown in Table 28.

Table 28. Sample Buffer Pool Configuration
Buffer Pool
Suggested Buffer Pool Size
Page Size


50% of available memory

4 KB


25% of available memory

16 KB


32 MB

32 KB

Different operating systems support different maximum amounts of IBM DB2 addressable memory. Depending on the memory configuration of a given server, the suggested pool sizes for BUF4K and BUF16K buffer pools might exceed these maximums, requiring you to allocate a smaller percentage. To determine the optimal buffer pool sizes, use IBM DB2 monitoring features.

This topic is part of Configuring an IBM DB2 Database for Siebel Business Applications.

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