More outdated examples

I can find no suitable replacement for this example. Can anyone else?

---------------------------------------------------------------------------

Peter Eisentraut wrote:

This example in User's Guide section 7.2 doesn't work anymore at all:

tgl=> select @ text '-4.5' as "abs";
abs
-----
4.5
(1 row)

What really happens is this:

=> select @ text '-4.5' as "abs";
ERROR: Unable to identify a prefix operator '@' for type 'text'
You may need to add parentheses or an explicit cast

Again, delete or new example?

--
Peter Eisentraut peter_e@gmx.net

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  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 359-1001
  +  If your life is a hard drive,     |  13 Roberts Road
  +  Christ can be your backup.        |  Newtown Square, Pennsylvania 19073

Bruce Momjian <pgman@candle.pha.pa.us> writes:

I can find no suitable replacement for this example. Can anyone else?

Peter Eisentraut wrote:

This example in User's Guide section 7.2 doesn't work anymore at all:

tgl=> select @ text '-4.5' as "abs";

Both of the examples in this section have been obsoleted by our recent
elimination of a lot of implicit casts. This one would still work if
text-to-float8 were an implicit cast, but it's not anymore. Also,
though the second one still acts as described, the reason given for it
in the text is wrong: the system is not unable to choose among multiple
alternatives. Rather, it finds *no* alternatives, again because the
text-to-various-int-types casts are no longer implicit.

The closest similar cases that I can find for the first example are not
good replacements because they are also slated for destruction :-(.
Basically, I see us moving away from the preferred-type mechanism, and
perhaps eliminating it entirely soon.

I'd just remove the whole of Example 7.3, I think. The mechanisms are
still there, for now, but they are not invoked in any standard cases.

regards, tom lane

The following applied patch removes the section Tom thought wasn't
needed anymore.

---------------------------------------------------------------------------

Tom Lane wrote:

Bruce Momjian <pgman@candle.pha.pa.us> writes:

I can find no suitable replacement for this example. Can anyone else?

Peter Eisentraut wrote:

This example in User's Guide section 7.2 doesn't work anymore at all:

tgl=> select @ text '-4.5' as "abs";

Both of the examples in this section have been obsoleted by our recent
elimination of a lot of implicit casts. This one would still work if
text-to-float8 were an implicit cast, but it's not anymore. Also,
though the second one still acts as described, the reason given for it
in the text is wrong: the system is not unable to choose among multiple
alternatives. Rather, it finds *no* alternatives, again because the
text-to-various-int-types casts are no longer implicit.

The closest similar cases that I can find for the first example are not
good replacements because they are also slated for destruction :-(.
Basically, I see us moving away from the preferred-type mechanism, and
perhaps eliminating it entirely soon.

I'd just remove the whole of Example 7.3, I think. The mechanisms are
still there, for now, but they are not invoked in any standard cases.

regards, tom lane

-- 
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 359-1001
  +  If your life is a hard drive,     |  13 Roberts Road
  +  Christ can be your backup.        |  Newtown Square, Pennsylvania 19073

The specific case that Tom complained about wasn't even in the latest
documentation sources anymore. I think the patch should be reverted.

Bruce Momjian writes:

The following applied patch removes the section Tom thought wasn't
needed anymore.

---------------------------------------------------------------------------

Tom Lane wrote:

Bruce Momjian <pgman@candle.pha.pa.us> writes:

I can find no suitable replacement for this example. Can anyone else?

Peter Eisentraut wrote:

This example in User's Guide section 7.2 doesn't work anymore at all:

tgl=> select @ text '-4.5' as "abs";

Both of the examples in this section have been obsoleted by our recent
elimination of a lot of implicit casts. This one would still work if
text-to-float8 were an implicit cast, but it's not anymore. Also,
though the second one still acts as described, the reason given for it
in the text is wrong: the system is not unable to choose among multiple
alternatives. Rather, it finds *no* alternatives, again because the
text-to-various-int-types casts are no longer implicit.

The closest similar cases that I can find for the first example are not
good replacements because they are also slated for destruction :-(.
Basically, I see us moving away from the preferred-type mechanism, and
perhaps eliminating it entirely soon.

I'd just remove the whole of Example 7.3, I think. The mechanisms are
still there, for now, but they are not invoked in any standard cases.

regards, tom lane

--
Peter Eisentraut peter_e@gmx.net

OK, readded. Thanks.

---------------------------------------------------------------------------

Peter Eisentraut wrote:

The specific case that Tom complained about wasn't even in the latest
documentation sources anymore. I think the patch should be reverted.

Bruce Momjian writes:

The following applied patch removes the section Tom thought wasn't
needed anymore.

---------------------------------------------------------------------------

Tom Lane wrote:

Bruce Momjian <pgman@candle.pha.pa.us> writes:

I can find no suitable replacement for this example. Can anyone else?

Peter Eisentraut wrote:

This example in User's Guide section 7.2 doesn't work anymore at all:

tgl=> select @ text '-4.5' as "abs";

Both of the examples in this section have been obsoleted by our recent
elimination of a lot of implicit casts. This one would still work if
text-to-float8 were an implicit cast, but it's not anymore. Also,
though the second one still acts as described, the reason given for it
in the text is wrong: the system is not unable to choose among multiple
alternatives. Rather, it finds *no* alternatives, again because the
text-to-various-int-types casts are no longer implicit.

The closest similar cases that I can find for the first example are not
good replacements because they are also slated for destruction :-(.
Basically, I see us moving away from the preferred-type mechanism, and
perhaps eliminating it entirely soon.

I'd just remove the whole of Example 7.3, I think. The mechanisms are
still there, for now, but they are not invoked in any standard cases.

regards, tom lane

--
Peter Eisentraut peter_e@gmx.net

-- 
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 359-1001
  +  If your life is a hard drive,     |  13 Roberts Road
  +  Christ can be your backup.        |  Newtown Square, Pennsylvania 19073