Allow LEAKPROOF functions for better performance of security views.

We don't normally allow quals to be pushed down into a view created
with the security_barrier option, but functions without side effects
are an exception: they're OK.  This allows much better performance in
common cases, such as when using an equality operator (that might
even be indexable).

There is an outstanding issue here with the CREATE FUNCTION / ALTER
FUNCTION syntax: there's no way to use ALTER FUNCTION to unset the
leakproof flag.  But I'm committing this as-is so that it doesn't
have to be rebased again; we can fix up the grammar in a future
commit.

KaiGai Kohei, with some wordsmithing by me.

1 files changed, 2 insertions, 0 deletions

diff --git a/src/include/optimizer/clauses.h b/src/include/optimizer/clauses.h
index fe241c708dc..1713b70400e 100644
--- a/src/include/optimizer/clauses.h
+++ b/src/include/optimizer/clauses.h
@@ -61,6 +61,8 @@ extern bool contain_subplans(Node *clause);
 extern bool contain_mutable_functions(Node *clause);
 extern bool contain_volatile_functions(Node *clause);
 extern bool contain_nonstrict_functions(Node *clause);
+extern bool contain_leaky_functions(Node *clause);
+
 extern Relids find_nonnullable_rels(Node *clause);
 extern List *find_nonnullable_vars(Node *clause);
 extern List *find_forced_null_vars(Node *clause);