Обсуждение: plug-n-play MS SQL Server replacement
I've been using PostgreSQL for a few months now and am very happy with its functionality and performance. Top-notch product that competes favorably with every DB I've used. However, most of my tables are still in MS SQL Server 2000 Enterprise. I often have to make it my target for purposes of compatibility. On some applications, the license costs are killers at around $400/client. So, here's my thought. How difficult would it be to build a server daemon that used PostgreSQL on the backend, and presented it to the network as a SQL Server compatible DB? Some of the work is already available in the 'tsql' client. This must've been thought of before, but does this idea have legs?
Lane, > So, here's my thought. How difficult would it be to build a server daemon > that used PostgreSQL on the backend, and presented it to the network as a > SQL Server compatible DB? I think you're on the wrong list for this question. I take it you're talking a compatibitily layer, like Rosetta? I would think that writing a program to broker requests on port 1433 and re-interpret SQL Server specific syntax would be a managable project for a good C or Perl hacker. What would be difficult-to-impossible is: 1) making it scale & perform well (in my experience, MS SQL Server accessed through Rosetta loses about 40% performance and is very limited in scalability). 2) Making it integrate well with MS networking and the MS ODBC/OLEDB/ADO/.NET clients. Also, if you have T-SQL procedures, you would have to somehow implement T-SQL for Postgres; translating the procedures is really not an option. -- -Josh Berkus Aglio Database Solutions San Francisco
Quoth josh@agliodbs.com (Josh Berkus): > Also, if you have T-SQL procedures, you would have to somehow implement T-SQL > for Postgres; translating the procedures is really not an option. You would be hit by a lot of other similar sorts of "impedances" to those found with MySQL. Most conspicuously, MySQL is most likely an imitator of Sybase (progenitor of the code that Microsoft sells) in having "autoincrementing columns" as compared to PostgreSQL's notion of "sequence objects." -- wm(X,Y):-write(X),write('@'),write(Y). wm('cbbrowne','ntlug.org'). http://cbbrowne.com/info/spreadsheets.html Monday is an awful way to spend one seventh of your life. -- Unknown
Chris, > Most conspicuously, MySQL is most likely an imitator of Sybase > (progenitor of the code that Microsoft sells) in having > "autoincrementing columns" as compared to PostgreSQL's notion of > "sequence objects." Nope. AUTO_INCREMENT is in the SQL 99 spec. It's actually well-supported in the industry. Eventually we'll probably come up with a command to emulate it using sequences so that we can have the SQL-compliance points. Mind you, AUTO_INCREMENT is one of those things that the SQL committee screwed up on, like the INTERVAL type. And don't know Sybase, it's a pretty good system with some features we could do worse than steal. -- -Josh Berkus Aglio Database Solutions San Francisco
On Fri, 2004-02-20 at 20:52, Josh Berkus wrote: > Chris, > > > Most conspicuously, MySQL is most likely an imitator of Sybase > > (progenitor of the code that Microsoft sells) in having > > "autoincrementing columns" as compared to PostgreSQL's notion of > > "sequence objects." > > Nope. AUTO_INCREMENT is in the SQL 99 spec. It's actually well-supported > in the industry. Eventually we'll probably come up with a command to > emulate it using sequences so that we can have the SQL-compliance points. Are you sure about that? A search for AUTO_INCREMENT doesn't give me anything. The DB2 style sequence GENERATORs are a part of the 2002 draft.
Rod Taylor wrote: > On Fri, 2004-02-20 at 20:52, Josh Berkus wrote: > >>Chris, >> >> >>>Most conspicuously, MySQL is most likely an imitator of Sybase >>>(progenitor of the code that Microsoft sells) in having >>>"autoincrementing columns" as compared to PostgreSQL's notion of >>>"sequence objects." >> >>Nope. AUTO_INCREMENT is in the SQL 99 spec. It's actually well-supported >>in the industry. Eventually we'll probably come up with a command to >>emulate it using sequences so that we can have the SQL-compliance points. > > > Are you sure about that? A search for AUTO_INCREMENT doesn't give me > anything. > http://troels.arvin.dk/db/rdbms/#mix-identity ? > The DB2 style sequence GENERATORs are a part of the 2002 draft. > > > > ---------------------------(end of broadcast)--------------------------- > TIP 1: subscribe and unsubscribe commands go to majordomo@postgresql.org -- Command Prompt, Inc., home of Mammoth PostgreSQL - S/ODBC and S/JDBC Postgresql support, programming shared hosting and dedicated hosting. +1-503-667-4564 - jd@commandprompt.com - http://www.commandprompt.com Mammoth PostgreSQL Replicator. Integrated Replication for PostgreSQL
Вложения
> > Are you sure about that? A search for AUTO_INCREMENT doesn't give me > > anything. > > > > http://troels.arvin.dk/db/rdbms/#mix-identity ? That URL simply makes it clear that AUTO_INCREMENT is in no way the SQL spec. Chris
> > http://troels.arvin.dk/db/rdbms/#mix-identity ? > > That URL simply makes it clear that AUTO_INCREMENT is in no way the SQL > spec. Ahh yea, I was just providing some further input. > > Chris > > -- Co-Founder Command Prompt, Inc. The wheel's spinning but the hamster's dead
Chris, Rod, etc: > That URL simply makes it clear that AUTO_INCREMENT is in no way the SQL > spec. Sorry! I was getting IDENTITY and AUTO_INCREMENT mixed up, since IDENTITY is what SQL Server supports. -- -Josh Berkus Aglio Database Solutions San Francisco