17.10 - DictionaryCacheSize - Advanced SQL Engine - Teradata Database

Teradata Vantage™ - Database Utilities

Product
Advanced SQL Engine
Teradata Database
Release Number
17.10
Release Date
July 2021
Content Type
Configuration
Publication ID
B035-1102-171K
Language
English (United States)

Defines the size in kilobytes of the dictionary cache for each PE on the system.

Field Group

Performance

Valid Range

0, and 64 KB through 65536 KB

Setting this field to 0 means to use the Teradata default value.

Default

8192 KB

Changes Take Effect

After the next database restart.

Usage Notes

The value of DictionaryCacheSize should be a multiple of the value of DictionaryCacheSegmentSize.

DictionaryCacheSize Performance Implications

The default value allows more caching of table header and database object access rights information, and reduces the number of I/Os required. It is especially effective for workloads that access many tables (more than 200) and for those that generate many dictionary seeks.

Increase the size of the dictionary cache to allow the parser to cache additional data dictionary and table header information.

For tactical and Online Complex Processing (OLCP) type workloads, maintaining a consistently short, few-second response time is important. These workloads may benefit from a larger dictionary cache, particularly when their query plans have not been cached in the request cache. A larger dictionary cache will allow more dictionary detail, needed for parsing and optimizing, to remain in memory for a longer period of time. For query workloads with a response time of more than one minute, there may be no measurable difference when this field is set to a higher value.

Related Information

For more information on… See…
DictionaryCacheSegmentSize DictionaryCacheSegmentSize.