Re: final patch - plpgsql: for-in-array

On Wed, Nov 24, 2010 at 1:06 AM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> =?ISO-8859-1?Q?C=E9dric_Villemain?= <cedric(dot)villemain(dot)debian(at)gmail(dot)com> writes:
>> I think you (Robert) misunderstood dramatically what Pavel try to do.
>> Pavel did an excellent optimization work for a specific point. This
>> specific point looks crucial for me in the current behavior of
>> PostgreSQL[1]. AFAIS Pavel didn't want to implement a genious syntax,
>> but an optimization feature.
>
> As near as I can tell, Pavel is bullheadedly insisting on adding new
> syntax, not on the optimization aspect of it.  I already pointed out
> how he could get 100% of the performance benefit using the existing
> syntax, but he doesn't appear to be willing to pursue that route.

Right, that was my impression, too. But, I think this may be partly a
case of people talking past each other. My impression of this
conversation was a repetition of this sequence:

A: This syntax is bad.
B: But it's way faster!

...which makes no sense. However, what I now think is going on here
is that there are really two separate things that are wished for here
- a more compact syntax, and a performance improvement. And taken
separately, I agree with both of those desires. PL/pgsql is an
incredibly clunky language syntactically, and it's also slow. A patch
that improves either one of those things has value, whether or not it
also does the other one.

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company