From 22deafe15289d2be55682e1632016004b02b62c0 Mon Sep 17 00:00:00 2001 From: Mike Bayer Date: Fri, 3 Dec 2021 14:04:05 -0500 Subject: Warn when caching is disabled / document This patch adds new warnings for all elements that don't indicate their caching behavior, including user-defined ClauseElement subclasses and third party dialects. it additionally adds new documentation to discuss an apparent performance degradation in 1.4 when caching is disabled as a result in the significant expense incurred by ORM lazy loaders, which in 1.3 used BakedQuery so were actually cached. As a result of adding the warnings, a fair degree of lesser used SQL expression objects identified that they did not define caching behavior so would have been producing ``[no key]``, including PostgreSQL constructs ``hstore`` and ``array``. These have been amended to use inherit cache where appropriate. "on conflict" constructs in PostgreSQL, MySQL, SQLite still explicitly don't generate a cache key at this time. The change also adds a test for all constructs via assert_compile() to assert they will not generate cache warnings. Fixes: #7394 Change-Id: I85958affbb99bfad0f5efa21bc8f2a95e7e46981 --- lib/sqlalchemy/dialects/postgresql/ext.py | 2 ++ 1 file changed, 2 insertions(+) (limited to 'lib/sqlalchemy/dialects/postgresql/ext.py') diff --git a/lib/sqlalchemy/dialects/postgresql/ext.py b/lib/sqlalchemy/dialects/postgresql/ext.py index f779a8010..e323da8be 100644 --- a/lib/sqlalchemy/dialects/postgresql/ext.py +++ b/lib/sqlalchemy/dialects/postgresql/ext.py @@ -54,6 +54,7 @@ class aggregate_order_by(expression.ColumnElement): __visit_name__ = "aggregate_order_by" stringify_dialect = "postgresql" + inherit_cache = False def __init__(self, target, *order_by): self.target = coercions.expect(roles.ExpressionElementRole, target) @@ -99,6 +100,7 @@ class ExcludeConstraint(ColumnCollectionConstraint): __visit_name__ = "exclude_constraint" where = None + inherit_cache = False create_drop_stringify_dialect = "postgresql" -- cgit v1.2.1