Module mz_transform::literal_constraints

See if there are predicates of the form <expr>=literal that can be sped up using an index. More specifically, look for an MFP on top of a Get, where the MFP has an appropriate filter, and the Get has a matching index. Convert these to IndexedFilter joins, which is a semi-join with a constant collection.

E.g.: Logically, we go from something like SELECT f1, f2, f3 FROM t WHERE t.f1 = lit1 AND t.f2 = lit2 to SELECT f1, f2, f3 FROM t, (SELECT * FROM (VALUES (lit1, lit2))) as filter_list WHERE t.f1 = filter_list.column1 AND t.f2 = filter_list.column2

Structs

LiteralConstraints

Convert literal constraints into IndexedFilter joins.

Statics

CALLSITE 🔒

META 🔒

Functions

each_or_arg_constrains_each_key_field 🔒

undo_preparation 🔒

The above preparation might make the MFP more complicated, so we’ll later want to either undo the preparation transformations or get back to orig_mfp.