diff --git a/lib/alog/connection.ex b/lib/alog/connection.ex
index 775cbd2..03aa313 100644
--- a/lib/alog/connection.ex
+++ b/lib/alog/connection.ex
@@ -2,15 +2,49 @@ defmodule Alog.Connection do
   @behaviour Ecto.Adapters.SQL.Connection
 
   @impl true
-  defdelegate ddl_logs(result), to: Ecto.Adapter.Postgres
+  defdelegate child_spec(opts), to: Ecto.Adapters.Postgres.Connection
+
+  @impl true
+  defdelegate ddl_logs(result), to: Ecto.Adapter.Postgres.Connection
 
   @impl true
   defdelegate prepare_execute(connection, name, statement, params, options),
-    to: Ecto.Adapter.Postgres
+    to: Ecto.Adapter.Postgres.Connection
 
   @impl true
-  defdelegate query(connection, statement, params, options), to: Ecto.Adapter.Postgres
+  defdelegate query(connection, statement, params, options), to: Ecto.Adapter.Postgres.Connection
 
   @impl true
-  defdelegate stream(connection, statement, params, options), to: Ecto.Adapter.Postgres
+  defdelegate stream(connection, statement, params, options), to: Ecto.Adapter.Postgres.Connection
+
+  @impl true
+  def execute_ddl({c, %Ecto.Migration.Table{} = table, columns} = command)
+      when c in [:create, :create_if_not_exists] do
+    case Enum.any?(
+           columns,
+           fn
+             {:add, field, type, [primary_key: true]} -> true
+             _ -> false
+           end
+         ) do
+      true ->
+        raise ArgumentError, "you cannot add a primary key"
+
+      false ->
+        Ecto.Adapter.Postgres.Connection.execute_ddl(
+          {c, table, subcommand ++ [{:add, :cid, "varchar", [primary_key: true]}]}
+        )
+    end
+  end
+
+  def execute_ddl({:alter, %Ecto.Migration.Table{}, changes} = command) do
+  end
+
+  def execute_ddl({:create, %Ecto.Migration.Index{}} = command) do
+  end
+
+  def execute_ddl({:create_if_not_exists, %Ecto.Migration.Index{}} = command) do
+  end
+
+  defdelegate execute_ddl(command), to: Ecto.Adapter.Postgres.Connection
 end