Search Conditions for Key Columns
If
search conditions are specified for key columns, the search is limited to the corresponding part of the table, that is, the search strategy is determined as specified in the table.
Search Condition |
Search Strategy |
Equality condition for every key column |
The system accesses the appropriate table line(s) directly. |
IN condition for one key column and an equality condition for all other key columns |
The system accesses the appropriate table line(s) directly. |
Any other search condition for the key columns |
Upper and lower limits are created for the key columns for the valid search area. All search strategies, including strategies through inversions, use the knowledge of this valid search area. |