diff options
Diffstat (limited to 'lib/sqlalchemy/dialects/mssql/pyodbc.py')
| -rw-r--r-- | lib/sqlalchemy/dialects/mssql/pyodbc.py | 16 |
1 files changed, 11 insertions, 5 deletions
diff --git a/lib/sqlalchemy/dialects/mssql/pyodbc.py b/lib/sqlalchemy/dialects/mssql/pyodbc.py index 978c501c4..f9f2479ad 100644 --- a/lib/sqlalchemy/dialects/mssql/pyodbc.py +++ b/lib/sqlalchemy/dialects/mssql/pyodbc.py @@ -291,9 +291,10 @@ Fast Executemany Mode --------------------- .. note:: SQLAlchemy 2.0 now includes an equivalent "fast executemany" - handler for INSERT statements that is more robust than the PyODBC feature; + handler for INSERT statements that is more robust than the PyODBC feature + (but is not quite as performant particularly for very large datasets); the feature is called :ref:`insertmanyvalues <engine_insertmanyvalues>` - and is enabled by default for all INSERT statements used by SQL Server. + and is enabled for all INSERT statements by default. SQLAlchemy's feature integrates with the PyODBC ``setinputsizes()`` method which allows for more accurate specification of datatypes, and additionally uses a dynamically sized, batched approach that scales to any number of @@ -301,9 +302,12 @@ Fast Executemany Mode The SQL Server ``fast_executemany`` parameter may be used at the same time as ``insertmanyvalues`` is enabled; however, the parameter will not be used - in as many cases as INSERT statements that are invoked using Core - :class:`_dml.Insert` constructs as well as all ORM use no longer use the - ``.executemany()`` DBAPI cursor method. + for INSERT statements that include RETURNING. + +.. versionchanged:: 2.0.9 - ``fast_executemany`` executions will be used + for INSERT statements that don't include RETURNING, when + ``fast_executemany`` is set. Previously, ``use_insertmanyvalues`` would + cause ``fast_executemany`` to not be used in most cases. The PyODBC driver includes support for a "fast executemany" mode of execution which greatly reduces round trips for a DBAPI ``executemany()`` call when using @@ -662,6 +666,8 @@ class MSDialect_pyodbc(PyODBCConnector, MSDialect): 8, ) self.fast_executemany = fast_executemany + if fast_executemany: + self.use_insertmanyvalues_wo_returning = False def _get_server_version_info(self, connection): try: |