PMPC_SessionRateThreshold - Advanced SQL Engine - Teradata Database

Database Utilities

Product
Advanced SQL Engine
Teradata Database
Release Number
17.00
Published
June 2020
Language
English (United States)
Last Update
2020-06-15
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B035-1102
lifecycle
previous
Product Category
Teradata Vantageā„¢

Purpose

Specifies the threshold above which the session cache is refreshed on demand, based on the session rate and last collection time.

PMPC_SessionRateThreshold should changed only under the direction of Teradata Support Center personnel.

Field Group

General

Valid Range

0 through 600 seconds

Default

60 seconds

Changes Take Effect

After the DBS Control Record has been written.

Usage Notes

This setting is effective only when workloads are enabled from the Viewpoint Workload Designer portlet.

The session cache is refreshed on demand under these conditions:

  • Workloads are enabled, and the Workload Exception Interval is greater than PMPC_SessionRateThreshold
  • Workloads are not enabled

If neither of the conditions are met, the session cache is refreshed automatically, once during every exception interval period.

Typically the Exception Interval is less than 60 seconds, so the cache is refreshed automatically.

For best performance and the lowest system overhead, Teradata recommends that the session cache be refreshed automatically.