Method and apparatus for loading data into multi-table tablespace

摘要

A relational database load operation is disclosed for loading data into a multi-table tablespace, such as a segmented tablespace in a DB2® environment. In one aspect, the load operation allows one or more tables to be replaced in a single pass of the tablespace without modifying, loading or replacing other tables in the tablespace. Thus, the disclosed operation can replace one or more tables in a single pass of the tablespace without the need to unload and reload tables not targeted for replacement. In another aspect, the load operation allows for a combined operation where one or more tables are replaced and one or more tables are resumed in a single pass of the multi-table tablespace without modifying other tables already residing in the tablespace.

主权项

1. A relational database load operation for a segmented tablespace of an IBM Database 2 (DB2) environment, the segmented tablespace having at least a first table and a second table, the load operation comprising:
receiving a request to replace data in the first table with replacement data and to resume original data in the second table with new data, the first table and the second table being stored in separate segments of the segmented tablespace, and the replacement data differing from the data in the first table; creating a copy of original spacemap pages for the tablespace; determining reclaimable segments in the tablespace, the reclaimable segments comprising segments assigned to the first table but not segments assigned to the second table; replacing the data in the first table by loading the reclaimable segments in the tablespace with the replacement data, while the original data of the second table remains in place in the tablespace without being resumed or replaced, updating the copy of the spacemap pages as the reclaimable segments are loaded; and adding the new data to the second table, so the second table includes the original data and the new data, wherein the acts of replacing, maintaining, and resuming are performed in a single pass through the segmented tablespace.