- remove add_constraint, this is not the current philosophy of the op package

- document most op methods
- add support for create_index, drop_index
- remove needless arguments from drop_table
- propagate arguemnts to UniqueConstraint

1 files changed, 11 insertions, 0 deletions

diff --git a/docs/build/ops.rst b/docs/build/ops.rst
index 92338a5..d4ed87d 100644
--- a/docs/build/ops.rst
+++ b/docs/build/ops.rst
@@ -10,6 +10,17 @@ The directives here are used within user-defined migration files,
 within the ``upgrade()`` and ``downgrade()`` functions, as well as 
 any functions further invoked by those.  
 
+A key design philosophy to the :mod:`alembic.op` functions is that
+to the greatest degree possible, they internally generate the 
+appropriate SQLAlchemy metadata, typically involving
+:class:`~sqlalchemy.schema.Table` and :class:`~sqlalchemy.schema.Constraint`
+objects.  This so that migration instructions can be 
+given in terms of just the string names and/or flags involved.   
+The exceptions to this
+rule include the :func:`.op.add_column` and :func:`.op.create_table`
+directives, which require full :class:`~sqlalchemy.schema.Column`
+objects, though the table metadata is still generated here.
+
 The functions here all require that a :class:`.Context` has been
 configured within the ``env.py`` script.  Under normal circumstances
 this is always the case, as the migration scripts are invoked via