Re: To Postgres Devs : Wouldn't changing the select limit - Mailing list pgsql-general

> Tom Lane writes:
>
> > ERROR:  LIMIT #,# syntax no longer supported.  Use LIMIT # OFFSET #.
> >     If translating pre-7.2 Postgres: LIMIT m,n => LIMIT m OFFSET n
> >     If translating MySQL: LIMIT m,n => OFFSET m LIMIT n
>
> I think someone is panicking here for no reason, but I'm not sure who it
> is.  If we think that LIMIT x,y should be phased out, then let's add that
> to the documentation and remove it in a later release, so people have a

We took a vote on 'general' and had only one person who wanted it kept
for an additional release and several who wanted it removed right now.

> chance to prepare.  But you're removing a perfectly fine feature that has

We are not removing the feature so much as forcing a syntax change on
user queries.

> received no attention in the last two years on the last day before beta

We have been _near_ beta for over one month now.  It doesn't seem wise
to let this time just go to waste so I am trying to do what I can to
move PostgreSQL forward during this period.

The LIMIT #,# was actuall changed a almost a month ago in gram.y:

    revision 2.253
    date: 2001/09/23 03:39:01;  author: momjian;  state: Exp;  lines: +3 -3
    Implement TODO item:

            * Change LIMIT val,val to offset,limit to match MySQL

This new activity is because someone asked about why the change was made
and the discussion on general led to this solution.

> because of a mysterious crowd of people porting from MySQL.  Let me tell
> you:  People porting from MySQL are going to have a lot of other problems
> before they find out that LIMIT works differently.

True.

> In addition I want to repeat my object to notices and errors that are
> teaching syntax or trying to give smart tips.  If a command is not
> syntactically correct then it's a syntax error.  If the command used to be
> correct, might be correct in the future, or is correct in some other life
> then it's still a syntax error.  If we want to have a "tip mode" then
> let's have one, but until that happens the documentation is the place to
> explain error messages or give advice how to avoid them.

I disagree.  If the 'tip' is localized to a few lines, usually in
gram.y, I don't see a reason not to help people find the right answer.
It helps them and reduces redundant bug repots.  I can't imagine a
reason not to do it unless it starts to make our code more complex.

I don't want to jump through hoops to give people tips, but if it is
easy, let's do it.

> Now, of course this whole situation is a bit unfortunate because of the
> syntax mixup.  But let's remember that most people that are going to use
> PostgreSQL 7.2 are the people that are using PostgreSQL 7.1 now, and
> they're going to be a lot happier the less they're going to be annoyed by
> gratuitous breaks in compatibility that had no prior notice at all.

Again, we took a vote on general.  If there are people who want this
kept around for another release, we can do it.  Let's hear from you.

--
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 853-3000
  +  If your life is a hard drive,     |  830 Blythe Avenue
  +  Christ can be your backup.        |  Drexel Hill, Pennsylvania 19026