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| author | Mike Bayer <mike_mp@zzzcomputing.com> | 2021-12-03 14:04:05 -0500 |
|---|---|---|
| committer | Mike Bayer <mike_mp@zzzcomputing.com> | 2021-12-06 18:27:19 -0500 |
| commit | 22deafe15289d2be55682e1632016004b02b62c0 (patch) | |
| tree | 5b521531418aebd4e293f848ebe4accbbd9bc5bc /lib/sqlalchemy/sql/base.py | |
| parent | e88dc004e6bcd1418cb8eb811d0aa580c2a44b8f (diff) | |
| download | sqlalchemy-22deafe15289d2be55682e1632016004b02b62c0.tar.gz | |
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
Diffstat (limited to 'lib/sqlalchemy/sql/base.py')
| -rw-r--r-- | lib/sqlalchemy/sql/base.py | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/lib/sqlalchemy/sql/base.py b/lib/sqlalchemy/sql/base.py index 6b0182751..4165751ca 100644 --- a/lib/sqlalchemy/sql/base.py +++ b/lib/sqlalchemy/sql/base.py @@ -769,11 +769,13 @@ class CacheableOptions(Options, HasCacheKey): return HasCacheKey._generate_cache_key_for_object(self) -class ExecutableOption(HasCopyInternals, HasCacheKey): +class ExecutableOption(HasCopyInternals): _annotations = util.EMPTY_DICT __visit_name__ = "executable_option" + _is_has_cache_key = False + def _clone(self, **kw): """Create a shallow copy of this ExecutableOption.""" c = self.__class__.__new__(self.__class__) @@ -847,7 +849,8 @@ class Executable(roles.StatementRole, Generative): """ self._with_options += tuple( - coercions.expect(roles.HasCacheKeyRole, opt) for opt in options + coercions.expect(roles.ExecutableOptionRole, opt) + for opt in options ) @_generative |