Recomputed Index Selectivity

Recomputing index selectivity can improve performance if, for example, Firebird needs to choose between two indices for a certain query. When computing the index selectivity, Firebird re-evaluates the index values and updates its statistics.

You can reach this via the context menu on Schema and Indices.

Computing the selectivity of an index might take some time, especially on large databases. Database Workbench will show you the progress and current index it is requesting to recompute.

Using the menu option on any Indices list will recompute the selectivity for all indices in that list.

Using the menu option at the Schema node will also recompute the selectivity on any system-defined indices like indices for Primary Key Constraint or Foreign Key Constraints.