How SAP ASE Shrinks the Database

For database shrink operations that do not include pages 0 – 255, SAP ASE clears the logical pages and removes them from physical storage. Any data the logical pages contain is moved to other newly allocated pages in the same database.

SAP ASE removes from the databases disk map any cleared data pages that appear at the end of the database. However, if other pages appear in the database after the cleared pages, the cleared pages remain in the database's disk map but point to a null device, which cannot store data.

The resulting disk map may combine both actions—shortening the disk map for some pages, but pointing other pages to a null device.

Note: This version of SAP ASE does not support shrinking databases that include pages 0 - 255.