MSSQL compatibility layer

Hi All,

A few years ago I got bored over summer and wrote some code to act as an MSSQL compatibility layer to postgres. Mostly just to see if such a thing could work. The idea is that I can point the MSSQL Management Studio at the server running postgres and it looks like I am talking to an MSSQL server. Once I got it working to a basic level I went onto other things and kind of forgot about it until I was cleaning up my server a few days ago.

Right now the code is pretty rough. I've only implemented bits and pieces to a proof of concept stage so it's definitely way off being useful. At the moment the following pieces are in place:
. BackgroundWorker listening on port 1433 (hardcoded - I haven't implemented any of the udp/1434 discovery stuff)
. Parser to take TDS from an MSSQL client and make sense of it, and then take postgres results and send back to the client
. Parser to take T-SQL statements and convert them to postgresql
. Postgres data types for MSSQL types (the main ones at least) using an internal storage format compatible with TDS

It's also not really a way for an MSSQL client to access an existing postgres database, it's more about implementing an MSSQL-like database using postgres as the backend, so an application will think it is actually talking to an MSSQL server. I mostly don't use postgres types, just my own tds/tsql compatible types. I haven't explored what sort of performance impact this might have.

So right now you can connect, create a database, create/insert/select from some tables, etc. Stored procedures/functions should be working but I just tested against 9.6 and I get some error about permission denied, and then when I tried to grant access to sa to my tsql language I got some error about "GRANT and REVOKE are not allowed on untrusted languages" and haven't investigated yet.

I'm not really sure if anyone else would find this interesting, but the code is just sitting around on my server doing nothing at the moment. Let me know if you want to know more and I can send you a copy of the code (under GPL or whatever license). I'm not subscribed to the list so cc me or email me direct.

James