In versions of Adaptive Server earlier than 12.5.3, inserts into a partitioned data-only locked table with a placement index may have caused wasted space. This problem was more pronounced in tables with a higher number of partitions and with larger page sizes.
Adaptive Server version 12.5.3 avoids wasting extra space by filling up existing allocated extents in the target allocation page, even though these extents are assigned to other partitions. The net effect is that extents are allocated only when there are no free extents in the target allocation page.If you do not want to use this space allocation mechanism, activate command line trace flag 646 (-T646).