database - Is the index related to predicate, or are they independent entitites? -


it theoretical question can't seem head around. index related predicate, , if yes, how? in advance!

predicates ed codd, relational ideal.

indexes have more physical implementation of table. make searches faster (e.g. b-tree representation).

predicates can mapped clauses , indexes in actual implementations, think predicate more abstract , theoretical. doesn't know or care how decide implement relation. predicate still true whether table scan or index properly.


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