Provides default selectivity estimates (in parts per million) to the optimizer for leading constant LIKE predicates.
DEFAULT_LIKE_RANGE_SELECTIVITY_PPM sets the default selectivity for LIKE predicates, of the form LIKE 'string%' where the match string is a set of constant characters followed by a single wildcard character (%). The optimizer relies on this option when other selectivity information is not available.
If the column has either an LF index or a 1- or 2- or 3-byte FP index, the optimizer can get exact information and does not need to use this value.
Users can also specify selectivity in the query. User-supplied condition hints are described in Reference: Building Blocks, Tables, and Procedures.