Re: Porting MSSQL to PGSQL (Was: [OT] MySQL is bad, but

Jim C. Nasby wrote:
> On Sun, May 21, 2006 at 02:58:17PM -0700, Josh Berkus wrote:

>> Actually, porting TSQL to PL/pgSQL would be very hard. I speak as an expert
>> TSQL developer. For example, most data manipulation in TSQL is done through
>> updatable cursors, something we don't currently support.

There are plenty of direct runtime incompatibilities, that have to be
implemented not as language-to-language, but language-to-procedure.
That also makes them stick out as the first thing to refactor and reimplement,
once the basic working system has been ported :-)

Hadn't thought about updatable cursors, but solved that problem before in
SimbaExpress and SimbaFusion with (effectively) arrays of OID's.

That's what I love about PG: so many rich consistent facilities
that you can implement things that tie other DB's in knots.

>> Also, T-SQL uses
>> un-ordered, callable parameters for SPs, something which we *also* don't
>> support.

Not such a big. Any translation has full access to the catalog
(ported over to the target PG system) and the parser/translator
can fill in the blanks.

> And TSQL doesn't fail a transaction on an error, resulting in code like
>
> UPDATE ...
>
> if @@error = 0 then
> UPDATE ...
> end
> if @@error = 0 then
> ...
Yeah, transaction error behaviour always brings out the nasty incompatibilities
(Jim, was that a major problem on Project Lance?).
--
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Physicists think that reality approximates the equations.
Mathematicians never make the connection.