prefetch_size values

This section discusses updates and clarifications for the prefetch parameter, used in the select, update, and delete commands.

New valid values for prefetch_size

When using prefetch and designating the prefetch size (prefetch_size) the minimum is 2K and any power of two on the logical page size up to 16K. Usually, the prefetch_size is used in select, update and delete statements.

prefetch size options in kilobytes:

Logical page size

Prefetch size options


2, 4, 8 16


4, 8, 16, 32


8, 16, 32, 64


16, 32, 64, 128

The prefetch size specified in the query is only a suggestion. To allow the size specification configure the data cache at that size. If you do not configure the data cache to a specific size, the default prefetch size is used.

To configure the data cache size, use sp_cacheconfigure.