- attributes module and test suite moves underneath 'orm' package

- fixed table comparison example in metadata.txt
- docstrings all over the place
- renamed mapper _getattrbycolumn/_setattrbycolumn to get_attr_by_column,set_attr_by_column
- removed frommapper parameter from populate_instance().  the two operations can be performed separately
- fix to examples/adjacencytree/byroot_tree.py to fire off lazy loaders upon load, to reduce query calling
- added get(), get_by(), load() to MapperExtension
- re-implemented ExtensionOption (called by extension() function)
- redid _ExtensionCarrier to function dynamically based on __getattribute__
- added logging to attributes package, indicating the execution of a lazy callable
- going to close [ticket:329]

1 files changed, 7 insertions, 4 deletions

diff --git a/lib/sqlalchemy/engine/base.py b/lib/sqlalchemy/engine/base.py
index e348b19ee..e4ff22746 100644
--- a/lib/sqlalchemy/engine/base.py
+++ b/lib/sqlalchemy/engine/base.py
@@ -16,11 +16,14 @@ class ConnectionProvider(object):
         raise NotImplementedError()
 
 class Dialect(sql.AbstractDialect):
-    """Adds behavior to the execution of queries to provide 
-    support for column defaults, differences between paramstyles, quirks between post-execution behavior, 
-    and a general consistentization of the behavior of various DBAPIs. 
+    """Defines the behavior of a specific database/DBAPI.
+
+    Any aspect of metadata defintion, SQL query generation, execution, result-set handling,
+    or anything else which varies between databases is defined under the general category of 
+    the Dialect.  The Dialect acts as a factory for other database-specific object implementations 
+    including ExecutionContext, Compiled, DefaultGenerator, and TypeEngine.
     
-    The Dialect should also implement the following two attributes:
+    All Dialects implement the following attributes:
 
     positional - True if the paramstyle for this Dialect is positional