Change SMDS on z/OS

The Change SMDS (MQCMD_CHANGE_SMDS) command changes the attributes of shared message data set.

The Change SMDS (MQCMD_CHANGE_SMDS) command changes the current shared message data set options for the specified queue manager and CF structure.

SMDS (MQCFST)

Specifies the queue manager for which the shared message data set properties are to be changed, or an asterisk to change the properties for all shared message data sets associated with the specified CFSTRUCT.

CFStrucName (MQCFST)

The name of the CF application structure with SMDS parameters that we want to change (parameter identifier: MQCA_CF_STRUC_NAME).

The maximum length of the string is MQ_CF_STRUC_NAME_LENGTH.

Optional parameters

DSBufs (MQCFIN)

The shared message data set buffers group (parameter identifier: MQIA_CF_SMDS_BUFFERS).

Specifies the number of buffers to be allocated in each queue manager for accessing shared message data sets. The size of each buffer is equal to the logical block size.

A value in the range 1 - 9999 or MQDSB_DEFAULT.

When DEFAULT is used any previous value is overridden and the DSBUFS value from the CFSTRUCT definition is used. The size of each buffer is equal to the logical block size.

Value can not be set unless CFLEVEL(5) is defined.

DSEXPAND (MQCFIN)

The shared message data set expand option (parameter identifier: MQIACF_CF_SMDS_EXPAND).

Specifies whether or not the queue manager should expand a shared message data set when it is nearly full, and further blocks are required in the data set. The value can be any of the following values:

MQDSE_YES

The data set can be expanded.

MQDSE_NO

The data set cannot be expanded.

MQDSE_DEFAULT

Only returned on DISPLAY CFSTRUCT when not explicitly set

Value can not be set unless CFLEVEL(5) is defined.

Parent topic: Definitions of the Programmable Command Formats