Add division of labour

DIVISION_OF_LABOUR.txt

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+
+Communication with client (mainly processing client's input)
+  * understand and implement the postgres protocol
+  * setup of concurrent connections
+  * when client sends a query, we send it to the parser "component"
+
+Parsing can be started now
+  basically a function
+    String -> Result<Operation, ParsingError>
+
+Validation of operation
+  When parsing gives you an operation, it need not make sense (e.g. table doesn't exist)
+  So we need to validate the operation.
+  The output of the validation is
+    * relevant table
+    * an "augmented" operation (e.g. operation with type operation)
+    * reject when e.g. table doesn't exist, condition refers to non-existent column etc
+    * This phaze doesn't need access to rows nor indices, just table meta-data.
+
+==========Locking of tables should happen here========
+
+Interpretation:
+  Change the state of the table given the validated operation
+
+Responding to the client
+  * with error messages
+  * with success message (after insert/delete etc)
+  * with rows
+  
+==========Lock on the table should be dropped here===========
+
+Serialization/Desearilization to disk
+  * There are two approaches, one is incremental (and very hard)
+    the other is: when the server is shut down.
+
+
+
+