16.20 - DMEM Command: Some Usage Notes - IBM CICS Interface for Teradata

IBM CICS Interface for Teradata® Reference

prodname
IBM CICS Interface for Teradata
vrm_release
16.20
created_date
October 2018
category
Programming Reference
featnum
B035-2448-106K

When you use the DMEM command transit, remember the following:

  • The DMEM counters are stable for the life of CICS.

    This means that the counts and the free chain contents are maintained across DBCC restarts.

  • Free blocks of storage are not pre-allocated during DBCC initialization.

    This means that the MIN column is not significant.

    Blocks are placed on the free chain when released if the sum of #FRE plus ALOC is less than MAX.

    All storage used by CLI is shared storage and is not accounted for under the TCA of the requesting application.

  • For CICS releases prior to CICS/ESA 3.2, all memory used is below the 16 MB line.

    Therefore, large numbers for MAX can result in virtual storage impact below the line.

  • For CICS release CICS/ESA 3.2 and above, the free chain is only used for blocks that are above the 16 MB line.

    The response buffers for AMODE 24 applications may be below the line.

    For these, use of the free chain will be bypassed, but the DMEM counter will be updated.