CA Dataquery uses the Compound Boolean Selection Facility to evaluate the row selection criteria specified in the FIND statements of queries. Because of this, search optimization is done dynamically by the Compound Boolean Selection Facility. Each logical expression in a WITH statement is a predicate. The predicates supplied in the query as selection criteria are used to build a Compound Boolean Selection Facility request qualification area (RQA).
When the predicates in a FIND statement refers to columns containing signed numeric data of packed or zoned decimal format, it is important to be as specific as possible in the CA Datacom Datadictionary TYPE-NUMERIC attribute about what sign codes the columns contain. This will allow CA Dataquery to pass this information along to the Compound Boolean Selection Facility, which in turn allows the Compound Boolean Selection Facility to evaluate the predicates more efficiently because it restricts the traversal key value range.
For example, if the data contains only positive values with the X'C' sign code, then specify P for this attribute. This attribute must agree with the actual data or incorrect results will be obtained.
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