CA IDMS/DB Reorg physically places sorted set members in key sequence, keeping physical and logical clustering of set members the same. This reduces the number of I/Os required to walk the set and to retrieve a sorted member when a FIND/OBTAIN USING command is specified. CA IDMS/DB Reorg overflows the records with symbolic keys that are higher than those of records stored on the home page. This reduces the average number of I/Os required to search for a record occurrence.
A variable length, sorted VIA record that does not fit on its owner's page has its root portion stored there if the TARGETROOT parameter was specified. This reduces the average number of I/Os required to retrieve a sorted VIA member when using the FIND/OBTAIN USING command because CA IDMS/DB looks at the root. The TARGETROOT parameter is most useful when the sorted VIA records are large with small roots.
Optimizing VIA Records:
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