Subject | Strange selectivity |
---|---|
Author | Salvatore Besso |
Post date | 2003-10-01T17:43:49Z |
hello all,
is it normal that every index (auto generated by the database)
associated with foreign keys has a very strange selectivity value? I
have checked them with PlanAnalyzer and three queries and I get very
strange values, 127.0, 270.0 and 6.0; as far as I know the value for
selectivity should be between 0 and 1.0, or is there something I'm
missing?
Regards
Salvatore
is it normal that every index (auto generated by the database)
associated with foreign keys has a very strange selectivity value? I
have checked them with PlanAnalyzer and three queries and I get very
strange values, 127.0, 270.0 and 6.0; as far as I know the value for
selectivity should be between 0 and 1.0, or is there something I'm
missing?
Regards
Salvatore