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/dialects/postgresql/psycopg2.py | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-) (limited to 'lib/sqlalchemy/dialects/postgresql/psycopg2.py') diff --git a/lib/sqlalchemy/dialects/postgresql/psycopg2.py b/lib/sqlalchemy/dialects/postgresql/psycopg2.py index 9585dd467..a9408bcb0 100644 --- a/lib/sqlalchemy/dialects/postgresql/psycopg2.py +++ b/lib/sqlalchemy/dialects/postgresql/psycopg2.py @@ -592,13 +592,9 @@ class PGExecutionContext_psycopg2(PGExecutionContext): ident = "c_%s_%s" % (hex(id(self))[2:], hex(_server_side_id())[2:]) return self._dbapi_connection.cursor(ident) - def get_result_cursor_strategy(self, result): + def post_exec(self): self._log_notices(self.cursor) - return super(PGExecutionContext, self).get_result_cursor_strategy( - result - ) - def _log_notices(self, cursor): # check also that notices is an iterable, after it's already # established that we will be iterating through it. This is to get -- cgit v1.2.1