git.postgresql.org Git - postgresql.git/commit

git projects / postgresql.git / commit

summary | shortlog | log | commit | commitdiff | tree
(parent: 2b7334d) | patch

Refactor planner's pathkeys data structure to create a separate, explicit

Refactor planner's pathkeys data structure to create a separate, explicit
representation of equivalence classes of variables. This is an extensive
rewrite, but it brings a number of benefits:
* planner no longer fails in the presence of "incomplete" operator families
that don't offer operators for every possible combination of datatypes.
* avoid generating and then discarding redundant equality clauses.
* remove bogus assumption that derived equalities always use operators
named "=".
* mergejoins can work with a variety of sort orders (e.g., descending) now,
instead of tying each mergejoinable operator to exactly one sort order.
* better recognition of redundant sort columns.
* can make use of equalities appearing underneath an outer join.

35 files changed:

RSS Atom