From 77f1b7d236dba6b1c859bb428ef32d118ec372e6 Mon Sep 17 00:00:00 2001 From: Mike Bayer Date: Mon, 25 May 2020 22:36:44 -0400 Subject: callcount reductions and refinement for cached queries This commit includes that we've removed the "_orm_query" attribute from compile state as well as query context. The attribute created reference cycles and also added method call overhead. As part of this change, the interface for ORMExecuteState changes a bit, as well as the interface for the horizontal sharding extension which now deprecates the "query_chooser" callable in favor of "execute_chooser", which receives the contextual object. This will also work more nicely when we implement the new execution path for bulk updates and deletes. Pre-merge execution options for statement, connection, arguments all up front in Connection. that way they can be passed to the before_execute / after_execute events, and the ExecutionContext doesn't have to merge as second time. Core execute is pretty close to 1.3 now. baked wasn't using the new one()/first()/one_or_none() methods, fixed that. Convert non-buffered cursor strategy to be a stateless singleton. inline all the paths by which the strategy gets chosen, oracle and SQL Server dialects make use of the already-invoked post_exec() hook to establish the alternate strategies, and this is actually much nicer than it was before. Add caching to mapper instance processor for getters. Identified a reference cycle per query that was showing up as a lot of gc cleanup, fixed that. After all that, performance not budging much. Even test_baked_query now runs with significantly fewer function calls than 1.3, still 40% slower. Basically something about the new patterns just makes this slower and while I've walked a whole bunch of them back, it hardly makes a dent. that said, the performance issues are relatively small, in the 20-40% time increase range, and the new caching feature does provide for regular ORM and Core queries that are cached, and they are faster than non-cached. Change-Id: I7b0b0d8ca550c05f79e82f75cd8eff0bbfade053 --- lib/sqlalchemy/sql/base.py | 14 ++++---------- 1 file changed, 4 insertions(+), 10 deletions(-) (limited to 'lib/sqlalchemy/sql/base.py') diff --git a/lib/sqlalchemy/sql/base.py b/lib/sqlalchemy/sql/base.py index bb606a4d6..6415d4b37 100644 --- a/lib/sqlalchemy/sql/base.py +++ b/lib/sqlalchemy/sql/base.py @@ -470,12 +470,7 @@ class CompileState(object): return None @classmethod - def _get_plugin_compile_state_cls(cls, statement, plugin_name): - statement_plugin_name = statement._propagate_attrs.get( - "compile_state_plugin", "default" - ) - if statement_plugin_name != plugin_name: - return None + def _get_plugin_class_for_plugin(cls, statement, plugin_name): try: return cls.plugins[(plugin_name, statement.__visit_name__)] except KeyError: @@ -607,9 +602,6 @@ class Executable(Generative): def _disable_caching(self): self._cache_enable = HasCacheKey() - def _get_plugin_compile_state_cls(self, plugin_name): - return CompileState._get_plugin_compile_state_cls(self, plugin_name) - @_generative def options(self, *options): """Apply options to this statement. @@ -735,7 +727,9 @@ class Executable(Generative): "to execute this construct." % label ) raise exc.UnboundExecutionError(msg) - return e._execute_clauseelement(self, multiparams, params) + return e._execute_clauseelement( + self, multiparams, params, util.immutabledict() + ) @util.deprecated_20( ":meth:`.Executable.scalar`", -- cgit v1.2.1