From 44f55913267481165cd9dbfb6ebffa05a72424bd Mon Sep 17 00:00:00 2001 From: Mike Bayer Date: Thu, 31 Mar 2022 16:53:43 -0400 Subject: allow executemany values for ON CONFLICT DO NOTHING Scaled back a fix made for :ticket:`6581` where "executemany values" mode for psycopg2 were disabled for all "ON CONFLICT" styles of INSERT, to not apply to the "ON CONFLICT DO NOTHING" clause, which does not include any parameters and is safe for "executemany values" mode. "ON CONFLICT DO UPDATE" is still blocked from "executemany values" as there may be additional parameters in the DO UPDATE clause that cannot be batched (which is the original issue fixed by :ticket:`6581`). Fixes: #7880 Change-Id: Id3e23a0c6699333409a50148fa8923cb8e564bdc --- lib/sqlalchemy/dialects/postgresql/base.py | 19 +++++++++++++++++++ lib/sqlalchemy/dialects/postgresql/psycopg2.py | 2 +- 2 files changed, 20 insertions(+), 1 deletion(-) (limited to 'lib/sqlalchemy/dialects/postgresql') diff --git a/lib/sqlalchemy/dialects/postgresql/base.py b/lib/sqlalchemy/dialects/postgresql/base.py index bec987c46..9bfde4768 100644 --- a/lib/sqlalchemy/dialects/postgresql/base.py +++ b/lib/sqlalchemy/dialects/postgresql/base.py @@ -1429,6 +1429,7 @@ import re from uuid import UUID as _python_UUID from . import array as _array +from . import dml from . import hstore as _hstore from . import json as _json from . import ranges as _ranges @@ -2452,6 +2453,24 @@ class PGCompiler(compiler.SQLCompiler): return target_text + @util.memoized_property + def _is_safe_for_fast_insert_values_helper(self): + # don't allow fast executemany if _post_values_clause is + # present and is not an OnConflictDoNothing. what this means + # concretely is that the + # "fast insert executemany helper" won't be used, in other + # words we won't convert "executemany()" of many parameter + # sets into a single INSERT with many elements in VALUES. + # We can't apply that optimization safely if for example the + # statement includes a clause like "ON CONFLICT DO UPDATE" + + return self.insert_single_values_expr is not None and ( + self.statement._post_values_clause is None + or isinstance( + self.statement._post_values_clause, dml.OnConflictDoNothing + ) + ) + def visit_on_conflict_do_nothing(self, on_conflict, **kw): target_text = self._on_conflict_target(on_conflict, **kw) diff --git a/lib/sqlalchemy/dialects/postgresql/psycopg2.py b/lib/sqlalchemy/dialects/postgresql/psycopg2.py index dddce5a62..391368c5f 100644 --- a/lib/sqlalchemy/dialects/postgresql/psycopg2.py +++ b/lib/sqlalchemy/dialects/postgresql/psycopg2.py @@ -712,7 +712,7 @@ class PGDialect_psycopg2(_PGDialect_common_psycopg): self.executemany_mode & EXECUTEMANY_VALUES and context and context.isinsert - and context.compiled.insert_single_values_expr + and context.compiled._is_safe_for_fast_insert_values_helper ): executemany_values = ( "(%s)" % context.compiled.insert_single_values_expr -- cgit v1.2.1