MTRETAIN=Y or N determines whether the allocated rows and index areas are to be retained when an MT command is issued or whether they are to be reduced to the original allocation before table expansion. The default is “N”, the additional space is not retained.
Also see ZEROROWS—Zero Data Table Rows on De-allocation.
This option applies to the TSR being accessed by this region or job.
This option can be specified for all tableBASE interfaces.