Designing Tables and Indexes for Performance › Table Space Performance Recommendations › Use Segmented or Universal Table Spaces › Universal Table Spaces › Partition-by-Data-Growth Table Space

Partition-by-Data-Growth Table Space

Before DB2 9, partitioned tables required key ranges to determine the target partition for row placement. Partitioned tables provide more granular locking and parallel operations by spreading the data over more data sets. In DB2 9, you can partition according to data growth. This practice enables segmented tables to be partitioned as they grow, without the need for key ranges. As a result, segmented tables benefit from increased table space limits and SQL and utility parallelism that were formerly available only to partitioned tables. Also, with a partition-by-data-growth table space, you do not need to reorganize a table space to change the limit keys.

You can implement partition-by-growth table space organization in one of the following ways:

• Use the new MAXPARTITIONS clause on the CREATE TABLESPACE statement to specify the maximum number of partitions that the partition-by-growth table space can accommodate. The value that you specify in the MAXPARTITIONS clause is used to protect against run away applications that perform an insert in an infinite loop.
• Use the MAXPARTITIONS clause on the ALTER TABLESPACE statement to alter the maximum number of partitions to which an existing partition-by-growth table space can grow. This ALTER TABLESPACE operation acts as an immediate ALTER.