Drop reference/ddl

docs/datamodel/index.rst

@@ -76,8 +76,8 @@ Example:
   `Atom <https://atom.io/packages/edgedb>`_, and `Vim <https://github.com/
   geldata/edgedb-vim>`_.
 
-Migrations
-----------
+Migrations and DDL
+------------------
 
 Gel's baked-in migration system lets you painlessly evolve your schema over
 time. Just update the contents of your |.gel| file(s) and use the |Gel| CLI
@@ -90,6 +90,11 @@ to *create* and *apply* migrations.
   $ gel migrate
   Applied dbschema/migrations/00001.edgeql
 
+Migrations are sequences of *data definition language* (DDL) commands.
+DDL is a low level language that tells the database how exactly to change
+the schema. Don't worry, you won't need to write any DDL directly, the Gel
+server will generate it for you.
+
 For a full guide on migrations, refer to the :ref:`Creating and applying
 migrations <ref_intro_migrations>` guide or the
 :ref:`migrations reference <ref_datamodel_migrations>` section.

docs/datamodel/migrations.rst

@@ -77,13 +77,19 @@ For this use case you can use the :gelcmd:`watch` command, which will
 monitor your |.gel| files and automatically create and apply migrations
 for you in the background.
 
+.. _ref_eql_ddl:
 
 Data definition language (DDL)
 ==============================
 
 The migration plan is a sequence of DDL commands. DDL commands are low-level
 instructions that describe the changes to the schema.
 
+SDL and your |.gel| files are like a 3D printer: you design the final shape,
+and the system puts a database together for you. Using DDL is like building a
+house the traditional way: to add a window, you first need a frame; to have a
+frame, you need a wall; and so on.
+
 If your schema looks like this:
 
 .. code-block:: sdl

docs/reference/index.rst

@@ -13,7 +13,6 @@ Reference
 
 
     edgeql/index
-    ddl/index
     connection
     environment
     projects