Update sqlalchemy

libs/sqlalchemy/dialects/oracle/cx_oracle.py

@@ -77,7 +77,7 @@ with this feature but it should be regarded as experimental.
 Precision Numerics
 ------------------
 
-The SQLAlchemy dialect goes thorugh a lot of steps to ensure
+The SQLAlchemy dialect goes through a lot of steps to ensure
 that decimal numbers are sent and received with full accuracy.
 An "outputtypehandler" callable is associated with each
 cx_oracle connection object which detects numeric types and
@@ -89,6 +89,21 @@ this behavior, and will coerce the ``Decimal`` to ``float`` if
 the ``asdecimal`` flag is ``False`` (default on :class:`.Float`,
 optional on :class:`.Numeric`).
 
+Because the handler coerces to ``Decimal`` in all cases first,
+the feature can detract significantly from performance.
+If precision numerics aren't required, the decimal handling
+can be disabled by passing the flag ``coerce_to_decimal=False``
+to :func:`.create_engine`::
+
+    engine = create_engine("oracle+cx_oracle://dsn", 
+                        coerce_to_decimal=False)
+
+The ``coerce_to_decimal`` flag is new in 0.7.6.
+
+Another alternative to performance is to use the 
+`cdecimal <http://pypi.python.org/pypi/cdecimal/>`_ library; 
+see :class:`.Numeric` for additional notes.
+
 The handler attempts to use the "precision" and "scale"
 attributes of the result set column to best determine if
 subsequent incoming values should be received as ``Decimal`` as
@@ -468,6 +483,7 @@ class OracleDialect_cx_oracle(OracleDialect):
                 auto_convert_lobs=True, 
                 threaded=True, 
                 allow_twophase=True, 
+                coerce_to_decimal=True,
                 arraysize=50, **kwargs):
         OracleDialect.__init__(self, **kwargs)
         self.threaded = threaded
@@ -491,7 +507,12 @@ class OracleDialect_cx_oracle(OracleDialect):
         self._cx_oracle_unicode_types = types("UNICODE", "NCLOB")
         self._cx_oracle_binary_types = types("BFILE", "CLOB", "NCLOB", "BLOB") 
         self.supports_unicode_binds = self.cx_oracle_ver >= (5, 0)
-        self.supports_native_decimal = self.cx_oracle_ver >= (5, 0)
+
+        self.supports_native_decimal = (
+                                        self.cx_oracle_ver >= (5, 0) and 
+                                        coerce_to_decimal
+                                    )
+
         self._cx_oracle_native_nvarchar = self.cx_oracle_ver >= (5, 0)
 
         if self.cx_oracle_ver is None:
@@ -603,7 +624,9 @@ class OracleDialect_cx_oracle(OracleDialect):
                                     size, precision, scale):
             # convert all NUMBER with precision + positive scale to Decimal
             # this almost allows "native decimal" mode.
-            if defaultType == cx_Oracle.NUMBER and precision and scale > 0:
+            if self.supports_native_decimal and \
+                    defaultType == cx_Oracle.NUMBER and \
+                    precision and scale > 0:
                 return cursor.var(
                             cx_Oracle.STRING, 
                             255, 
@@ -614,7 +637,8 @@ class OracleDialect_cx_oracle(OracleDialect):
             # make a decision based on each value received - the type 
             # may change from row to row (!).   This kills
             # off "native decimal" mode, handlers still needed.
-            elif defaultType == cx_Oracle.NUMBER \
+            elif self.supports_native_decimal and \
+                    defaultType == cx_Oracle.NUMBER \
                     and not precision and scale <= 0:
                 return cursor.var(
                             cx_Oracle.STRING,