PL/pgSQL 2

Hi,

For those of you who use PL/pgSQL every day, I'm quite certain you all feel
there are a number of things you would like to change in the language, but
realize it cannot be achieved without possibly breaking compatibility, at
least in theory. Even though you own code would survive the change, there
might be code somewhere in the world which would break. This is of course
not acceptable and that's why we have the current status quo of
development, or at least not far away from a status quo.

So instead of continue to adding optional settings to the config file, and
instead of killing discussions around what can be done by bringing up the
backwards-compatibility argument, let's instead fork the language and call
it plpgsql2. Since no code is yet written in plpgsql2, we can start of from
a clean sheet, and no good ideas need to be killed due to
backwards-compatibility concerns.

The interest for such a project is probably limited to a small number of
companies/people around the world, as most users are probably perfectly
happy with the current version of plpgsql, as they only use it occasionally
and not every day like we do at my company.

Just like with plpgsql, once released, plpgsql2 cannot break compatibility
with future versions, so we only have one chance to carefully think though
what we would like to change in the language.

From the top of my head, these are Things I personally would want to see in
plpgsql2:
+ Make UPDATE/INSERT/DELETE throw error if they didnt' modify exactly 1
row, as that's the most common use-case, and provide alternative syntax to
modify multiple or zero rows.
+ Make SELECT .. INTO .. throw an error if it selects more than 1 row. INTO
STRICT only works if no rows should be an error, but there is currently no
nice way if no rows OR exactly 1 row should be found by the query.
+ Change all warnings into errors

These are small changes, probably possible with just a few hundred lines of
code in total, which also should be the ambition, as larger changes would
never survive during time as it would require too much efforts to keep up
with the main project. Secondly, I trust plpgsql mainly because it's being
used by a lot of people in a lot of production systems, the same would not
hold true for plpgsql2 for the first years of existence, so we who would
use it in production systems must understand every single line of code
changed and feel the risk of possible bugs and their impact are within
acceptable boundaries.

I can probably think of a few more things, but these are the major
annoyances.

Please share your wish list of things you would want in plpgsql2 which are
not possible to implement in plpgsql because they could possibly break
compatibility.

Regards, Joel