Bug: century/millenium still broken

Dear Tom,

After all that about numbering centuries and millenia correctly,
why does CVS tip still give me

regression=# select extract(century from now());
date_part
-----------
20
(1 row)
[ ... looks in code ... ]

Apparently it's because you fixed only timestamp_part, and not
timestamptz_part. I'm not too sure about what timestamp_trunc or
timestamptz_trunc should do, but they may be wrong as well.

Sigh... as usual, what is not tested does not work:-(

Could we have a more complete patch?

Please find a submission attached. I hope it really fixes all decade,
century and millenium issues for extract and *_trunc functions on interval
and other timestamp types. If someone could check that the results
are reasonnable, it would be great.

I indeed overlooked the fact that there were two functions. The patch
fixes the code so that both variants agree.

I added comments to interval extractions, because it relies on the C
division to have a negative remainder: -7/10 = 0 and remains -7.

As for *_trunc functions, I have chosen to put the first year of the
century or millennium: -100, 1, 101... 1001 2001 etc. Indeed, I don't
think it would make sense to put 2000 (last year of the 2nd millennium)
for rounding all years of the third millenium.

I also fixed the code so that all decades last 10 years and decade 199
means the 1990's.

I have added some tests that are relevant to deal with tricky cases. The
formula may be simplified, but all these cases must pass. Please keep
them.

Have a nice day,

--
Fabien Coelho - coelho@cri.ensmp.fr

Your patch has been added to the PostgreSQL unapplied patches list at:

http://momjian.postgresql.org/cgi-bin/pgpatches

It will be applied as soon as one of the PostgreSQL committers reviews
and approves it.

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

Fabien COELHO wrote:

Dear Tom,

After all that about numbering centuries and millenia correctly,
why does CVS tip still give me

regression=# select extract(century from now());
date_part
-----------
20
(1 row)
[ ... looks in code ... ]

Apparently it's because you fixed only timestamp_part, and not
timestamptz_part. I'm not too sure about what timestamp_trunc or
timestamptz_trunc should do, but they may be wrong as well.

Sigh... as usual, what is not tested does not work:-(

Could we have a more complete patch?

Please find a submission attached. I hope it really fixes all decade,
century and millenium issues for extract and *_trunc functions on interval
and other timestamp types. If someone could check that the results
are reasonnable, it would be great.

I indeed overlooked the fact that there were two functions. The patch
fixes the code so that both variants agree.

I added comments to interval extractions, because it relies on the C
division to have a negative remainder: -7/10 = 0 and remains -7.

As for *_trunc functions, I have chosen to put the first year of the
century or millennium: -100, 1, 101... 1001 2001 etc. Indeed, I don't
think it would make sense to put 2000 (last year of the 2nd millennium)
for rounding all years of the third millenium.

I also fixed the code so that all decades last 10 years and decade 199
means the 1990's.

I have added some tests that are relevant to deal with tricky cases. The
formula may be simplified, but all these cases must pass. Please keep
them.

Have a nice day,

--
Fabien Coelho - coelho@cri.ensmp.fr

Content-Description:

[ Attachment, skipping... ]

---------------------------(end of broadcast)---------------------------
TIP 8: explain analyze is your friend

-- 
  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

Patch applied. Thanks.

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

Fabien COELHO wrote:

Dear Tom,

After all that about numbering centuries and millenia correctly,
why does CVS tip still give me

regression=# select extract(century from now());
date_part
-----------
20
(1 row)
[ ... looks in code ... ]

Apparently it's because you fixed only timestamp_part, and not
timestamptz_part. I'm not too sure about what timestamp_trunc or
timestamptz_trunc should do, but they may be wrong as well.

Sigh... as usual, what is not tested does not work:-(

Could we have a more complete patch?

Please find a submission attached. I hope it really fixes all decade,
century and millenium issues for extract and *_trunc functions on interval
and other timestamp types. If someone could check that the results
are reasonnable, it would be great.

I indeed overlooked the fact that there were two functions. The patch
fixes the code so that both variants agree.

I added comments to interval extractions, because it relies on the C
division to have a negative remainder: -7/10 = 0 and remains -7.

As for *_trunc functions, I have chosen to put the first year of the
century or millennium: -100, 1, 101... 1001 2001 etc. Indeed, I don't
think it would make sense to put 2000 (last year of the 2nd millennium)
for rounding all years of the third millenium.

I also fixed the code so that all decades last 10 years and decade 199
means the 1990's.

I have added some tests that are relevant to deal with tricky cases. The
formula may be simplified, but all these cases must pass. Please keep
them.

Have a nice day,

--
Fabien Coelho - coelho@cri.ensmp.fr

Content-Description:

[ Attachment, skipping... ]

---------------------------(end of broadcast)---------------------------
TIP 8: explain analyze is your friend

-- 
  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