Purpose
Specifies the number of data blocks beyond the current block that will be preloaded into memory during the following sequential scan operations:
- File system startup
- File system utility (for example, Ferret) operations, such as SCANDISK, that occur when Teradata Database is not running
To enable the read-ahead feature, the ReadAhead field must be set to TRUE.
Field Group
Performance
Valid Range
1 through 100 blocks
Default
20 blocks
Changes Take Effect
After the DBS Control record has been written.
Usage Notes
The number of data blocks to be preloaded during file system utility operations when Teradata Database is running is determined by the UtilityReadAheadCount setting.