TDP Options - Teradata Director Program

Teradata® Director Program Reference

Product
Teradata Director Program
Release Number
16.20
Published
September 2019
Language
English (United States)
Last Update
2019-10-11
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B035-2416
lifecycle
previous
Product Category
Teradata Tools and Utilities

To provide for memory acquisition during system operation without incurring the high overhead associated with the GETMAIN/FREEMAIN memory services, TDP acquires units of main memory, or cells, from its own, more efficient memory manager.

During startup, the memory manager pre-allocates a number of cells in sizes that are convenient for use by TDP. The sizes of the cells are internal constants. The initial number of cells is an internal default.

WHEN a . . . THEN the . . .
TDP subtask requests a cell from the memory manager, but all available cells are being used by other TDP subtasks memory manager does one of the following:
  • Obtains a single cell using a GETMAIN call to the operating system
  • Places the requesting subtask into a wait for memory
requester is placed into a wait wait ends when another TDP subtask releases a cell.

The decision to use GETMAIN or wait is based on the cell size and the identity of the requesting subtask.