15.00 - NumStatisticsCacheSegs - Teradata Database

Teradata Database Utilities

Product
Teradata Database
Release Number
15.00
Content Type
Configuration
Publication ID
B035-1102-015K
Language
English (United States)
Last Update
2018-09-25

NumStatisticsCacheSegs

Purpose  

Specifies the number of segments maintained for the Optimizer statistics cache on each PE vproc.

Field Group

Performance

Valid Range

2 through 200

Default

4

Changes Take Effect

After the next Teradata Database restart.

Usage Notes  

The default size of each segment is 1024 KB.

The following situations may require a change from the default setting:

  • If parsing time increases for tables that have many statistics, increasing the number of cache segments may improve performance.
  • Systems with large amounts of memory can dedicate more memory to parsing when the number of cache segments is increased. This is useful for large memory systems.
  • If event logging on the statistics cache shows a low hit ratio, increasing the size of the cache can help.