DEFAULT_LIKE_MATCH_SELECTIVITY option

Provides default selectivity estimates to the optimizer for most LIKE predicates.

0 to 100

15

Can be set for an individual connection or the PUBLIC group. Takes effect immediately.

DEFAULT_LIKE_MATCH_SELECTIVITY sets the default selectivity for generic LIKE predicates, for example, LIKE 'string%string' where % is a wildcard character. The optimizer relies on this option when other selectivity information is not available and the match string does not start with a set of constant characters followed by a single wildcard.

If the column has either a LF index or a 1- or 2-byte FP index, the optimizer can get exact information and does not need to use this value.