- attach the ResultMetaData to the Compiled object, when we detect that

the compiled cache is used.  That allows us to cache the whole metadata
and save on creating it at result time, when compiled cache is used.

diff --git a/lib/sqlalchemy/engine/result.py b/lib/sqlalchemy/engine/result.py
index 6c98dae18631e69122aeaf41edcf042dd7fe723f..0838d810daf46fba5fd8ab95af2f9927119e0f4c 100644 (file)
--- a/lib/sqlalchemy/engine/result.py
+++ b/lib/sqlalchemy/engine/result.py
@@ -269,9 +269,6 @@ class ResultMetaData(object):
         # high precedence keymap.
         keymap.update(primary_keymap)
 
-        if parent._echo:
-            context.engine.logger.debug(
-                "Col %r", tuple(x[0] for x in metadata))
 
     @util.pending_deprecation("0.8", "sqlite dialect uses "
                     "_translate_colname() now")
@@ -406,7 +403,18 @@ class ResultProxy(object):
     def _init_metadata(self):
         metadata = self._cursor_description()
         if metadata is not None:
-            self._metadata = ResultMetaData(self, metadata)
+            if self.context.compiled and \
+                    'compiled_cache' in self.context.execution_options:
+                if self.context.compiled._cached_metadata:
+                    self._metadata = self.context.compiled._cached_metadata
+                else:
+                    self._metadata = self.context.compiled._cached_metadata = \
+                        ResultMetaData(self, metadata)
+            else:
+                self._metadata = ResultMetaData(self, metadata)
+            if self._echo:
+                    self.context.engine.logger.debug(
+                    "Col %r", tuple(x[0] for x in metadata))
 
     def keys(self):
         """Return the current set of string keys for rows."""

diff --git a/lib/sqlalchemy/sql/compiler.py b/lib/sqlalchemy/sql/compiler.py
index 11608ef3b95904e10b873e7589196ed6ce1b1ddb..010df5a1608625c06526e232fc2809e20c107c0d 100644 (file)
--- a/lib/sqlalchemy/sql/compiler.py
+++ b/lib/sqlalchemy/sql/compiler.py
@@ -170,6 +170,8 @@ class Compiled(object):
     defaults.
     """
 
+    _cached_metadata = None
+
     def __init__(self, dialect, statement, bind=None,
                 compile_kwargs=util.immutabledict()):
         """Construct a new ``Compiled`` object.