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Background documentation Search Conditions Linked with OR Locate the document in its SAP Library structure

There are search conditions linked with OR. The system analyzes the individual search conditions.

If the system finds an equality condition for key columns, it ignores the other search conditions linked with OR.

If the system does not find any equality conditions for key columns, the other search conditions linked with OR, that the system has not considered until then, are analyzed.

Procedure

  1. Conversion of the search condition into the disjunctive normal form
    Example:
    b1 and b2 and (b3 or b4 and b5)
    results in the disjunctive normal form
    (b1 and b2 and b3) or (b1 and b2 and b4 and b5)
  2. Analysis of the new expression
    Every bracketed expression is analyzed separately. If the analysis of the first expression results in the best search strategy, this is used. However, if the analysis of each bracketed expression provides a better search strategy, there are usually as many search strategies as there are bracketed expressions to be analyzed.
  3. Cost determination
    The costs of the various search strategies are added together. If the total is lower than the determined cost for the search strategy without consideration of the search conditions linked with OR, the various search strategies are used.

If applicable, the EXPLAIN statement displays the search strategy DIFFERENT STRATEGIES FOR OR-TERMS.

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