Database expansion is performed by a set of threshold action procedures fired when free space crosses a threshold set for a segment. sp_dbextend is the interface for administering and managing the expansion process for a specified segment or device.
You can configure automatic expansion to run with server-wide default expansion policies, or you can customize it for individual segments in specified databases.You can install thresholds on key segments on which tables with critical data reside, allowing you a fine degree of control over how Adaptive Server meets the data space requirements for different kinds of tables. If your site has key tables with large volumes of inserts, these tables can be bound to specific segments, with site-specific rules for extending that segment. This enables you to avoid outages that can occur in a production environment with large loads on such key tables.
You cannot use the thresholds to shrink a database or its segment.
For more information on sp_dbextend, see the Adaptive Server Reference Manual.
