DM_AUTOISICOMPACT Keyword

9.4D

     DM_AUTOISICOMPACT={ON|OFF}

The ISAM support in the Data Manager automatically compacts an ISI file when a PLB IO operation is executed where an ISAM key is to be inserted into the ISI tree structure. This change is being implemented to minimize the impact on end-user applications where an I62 error could be encountered as the PLB program is adding keys to an ISI file. The automatic ISI compact action can occur in any of the following PLB IO ISAM instructions:

WRITE IFILE

INSERT IFILE

WRITE FILELIST

UPDATE FILELIST

Note:

Since all of the PLB instructions that can invoke a compact action are guaranteed to have an enqueue lock applied, any other end-user applications with a pending lock on the text file associated with the ISI file will wait until the compact action is completed.

The automatic ISI compact action is implemented as the default behavior by the Data Manager. The Data Manager keyword named 'DM_AUTOISICOMPACT={on|off}' can be used to define the default behavior to be implemented. If this keyword is not specified, the default behavior is the same as being set to 'ON'. If this keyword is set to 'ON', the automatic ISI compacting is enabled for all IFILE variables. If this keyword is set to 'OFF', the runtime does not perform any automatic ISI compacting action unless the IFILE variable is opened using a new CMP_ISICOMPACT mode bit value.

Two new bit mask values have been added for the MODE option for an OPEN and PREPARE of an IFILE variable. The new MODE bit mask values have been implemented as follows:

If both the CMP_ISICOMPACT and CMP_NOISICOMPACT bit mask bits are set to a zero bit value or to a one bit value, the Data Manager uses the current default behavior that is being used by the Data Manager for the compacting action.

Example:

     DM_AUTOISICOMPACT=0x1000

See Also: SUNDM Keywords, SUNADMIN, MAKEMFD