Tables with a very large number of rows can take a very long time to load. The UNION ALL view is one way to address this issue. Sybase IQ lets you partition tables by splitting the data into several separate base tables (for example, by date). You then join them back together into a logical whole by means of a UNION ALL view.
UNION ALL views are simple to administer. If the data is partitioned by, for example, month, you can drop an entire month’s worth of data by deleting a table and updating the UNION ALL view definition appropriately. You can have many view definitions for a year, a quarter, and so on, without adding extra date range predicates.
For information on establishing UNION ALL views, and recommendations for optimizing queries that reference these views, see “Using UNION ALL views for faster loads” in Performance and Tuning Guide.
