Note some ideas

Notes.md

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+# ProcruSQL
+
+## Goals
+
+Declarative, Config declares how a schema should look like.
+
+In most cases, procrusql should figure out what it has to do.
+
+It must be possible to supply custom code, either because procrusql
+doesn't know what to do or because it can be done in a cleaner or faster
+way.
+
+Data migrations must be possible, for example:
+    * A new column is filled with data from an old old column.
+    * A new table is filled with data from existing tables
+    * New data is inserted into the database. This may require using
+      intermediate results (e.g. inserting data into into a master table
+      returns a new PK which is then used for inserts as the FK in a
+      detail table)
+
+Need some kind of dependency system (similar to make). 
+For example, if a migration requires creating a new table, copying data
+from an existing table and then dropping the old column, we have to make
+sure that happens in the right order.
+
+Syntax should be easy to read and write
+
+Syntax should be diff-friendly
+
+All changes should be done in a single transaction.
+
+## Non-Goals
+
+Reverting changes (instead apply the old config again).
+
+## Problems
+
+Is the order of operations always the same or is it sometimes necessary
+to do things in a different order depending on the current state?