Concepts › CA IDMS/DB Reorg Reorganization Capabilities › Reorganization Capabilities Controlled by Parameters

Reorganization Capabilities Controlled by Parameters

Most of CA IDMS/DB Reorg's parameters allow you to control internal physical reorganization functions for sets and records and to specify where the reorganization is to be performed. By using these parameters you can direct CA IDMS/DB Reorg to:

• Resolve record/page conflicts. The PRIORITY parameter allows you to specify which record types (or group of record types) are to be stored on the target page and which ones should overflow if the page is full. The priorities you assign take effect only when records overflow. The priorities you assigned to record types are used to determine which records receive priority storage locations and which ones should overflow if a page isn't large enough to store all records targeting to it.
• Define clustering. The PRIORITY parameter also allows you to define how VIA clusters are stored. The schema which follows this list shows how you can direct CA IDMS/DB Reorg to cluster VIA records in the order in which they are retrieved.
• Specify page reserve. CA IDMS/DB Reorg does not force you to create a special DMCL just to specify a page reserve for reorganization. CA IDMS/DB Reorg uses a parameter-defined value instead.
• Rebuild integrated indexes. CA IDMS/DB Reorg rebuilds all indices in an index area. This allows you to reduce or eliminate a number of intermediate-level index records that were created due to the order in which the member records were stored.
• Reduce the number of I/Os required to search a sorted set. For CALC and sorted VIA record types, you can specify by the TARGETROOT parameter that CA IDMS/DB Reorg is to store the root portion of the record, which contains the record's symbolic key, on the target page if the entire record will not fit. This reduces the number of I/Os required to search for a CALC or sorted VIA member. The remainder of the record is stored on as few pages as possible.

Resolving Record/Page Conflicts: