13.12.2 Facilities used to change partitioning storage conditions

This subsection describes the facilities used to change a table's partitioning storage conditions.

Organization of this subsection
(1) Split facility
(2) Combine facility

(1) Split facility

The split facility changes (splits) a table partitioning storage condition and stores the data from a single RDAREA into multiple RDAREAs. Figures 13-14 and 13-15 provide an overview of the split facility.

Figure 13-14 Overview of the split facility (in the case of boundary value specification)

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Figure 13-15 Overview of the split facility (in the case of storage condition specification)

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When a table is split, the data stored in the RDAREA that is to be split is deleted. Therefore it is necessary to first unload the data from the RDAREA that stores data under the old partitioning storage conditions, and then reload this data into the RDAREAs that will store the data under the new partitioning storage conditions. However, there is one exception: if the pre-splitting RDAREA is to be used as a post-splitting RDAREA without any change, you can keep the data that was stored before splitting without unloading and reloading it.

If you do not use the pre-splitting RDAREA as a post-splitting RDAREA, you cannot keep the data that was stored in the pre-splitting RDAREA.

(2) Combine facility

The combine facility changes (combines) partitioning storage conditions for a table and stores data from multiple RDAREAs into a single RDAREA. Figures 13-16 and 13-17 provide an overview of the combine facility.

Figure 13-16 Overview of the combine facility (in the case of boundary value specification)

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Figure 13-17 Overview of the combine facility (in the case of storage condition specification)

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When RDAREAs are combined, the data stored in the RDAREAs that are to be combined is deleted. Therefore it is necessary to first unload the data from the RDAREAs to be combined that store data under the old partitioning storage conditions, and then to reload this data into the RDAREA that will store the data under the new, combined partitioning storage conditions. However, there is one exception: if one of the pre-combination RDAREAs is to be used as the post-combination RDAREA, you can keep the data that was stored in it before combining.

If you do not use a pre-combining RDAREA as the post-combining RDAREA, you cannot keep the data that was stored in any of the pre-combining RDAREAs. To set the data that was stored in the pre-combining RDAREAs in the newly added RDAREA, you must unload the data from all RDAREAs before combining and then reload this data after combining.