When altering a segmented Tablespace from a segmented Tablespace to a Partition-by-Growth (PBG) Universal Tablespace (UTS), RC/Compare generates the following DDL to make the change:
ALTER TABLESPACE dbname.tsname MAXPARTITIONS 1
A Reorg utility is also generated to materialize the Tablespace to PBG UTS. Once the Reorg has been executed the SEGSIZE of the altered object is now 32G.
As per the DB2 SQL Reference Guide, if MAXPARTITIONS is specified on a simple or segmented table space, the table space is converted to a partition-by-growth universal table space that can grow to a maximum number of integer partitions. The SEGSIZE is set to the default of 32 if the SEGSIZE prior to conversion is less than 32.
If it is a requirement to retain the original SEGSIZE, then currently you must avoid using DB2 Alter. This can be done by performing a DROP/CREATE in the Analysis. To do this set the following Analysis Option to 'Y':
DROP & RE-CREATE ==> Y
Please refer to the alteration considerations section in the RC/Migrator documentation.