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 Search Conditions for Inverted Columns 

If the SQL statement contains search conditions for inverted columns, then the following search strategies are possible:

Search Condition

Search Strategy

Equality condition for all inverted columns

Those rows whose keys are included in the associated inversion list are accessed.

IN condition for inverted columns

The system accesses those rows whose keys are included in the inversion lists.

Range conditions with one condition only ( <, £, >, ³ ) for one of the two range limits (upper or lower limit)

The system accesses those rows whose keys are included in the inversion lists that were determined by the range.

Range conditions for which both range limits are specified. It is irrelevant to the selection of the search strategy whether this specification is made using a BETWEEN operator or using two conditions (£ or ³) for the same column linked by AND.

The system accesses those rows whose keys are included in the inversion lists that were determined by the range.

In the case of the equality/IN conditions and the range conditions, there are also queries for which it is not necessary to access the rows, since all required values are already included in the inversion list(s).

See also:

Examples: Search Conditions for Inverted Columns

 

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