Re: Conversion errors for datetime fields
От | Larry Rosenman |
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Тема | Re: Conversion errors for datetime fields |
Дата | |
Msg-id | 20001228203732.A4160@lerami.lerctr.org обсуждение исходный текст |
Ответ на | Re: Conversion errors for datetime fields (Larry Rosenman <ler@lerctr.org>) |
Ответы |
Re: Conversion errors for datetime fields
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Список | pgsql-bugs |
* Larry Rosenman <ler@lerctr.org> [001228 19:39]: > * Tom Lane <tgl@sss.pgh.pa.us> [001228 11:33]: > > Larry Rosenman <ler@lerctr.org> writes: > > > Aren't we *REQUIRED* by SQL99 to accept up to :61 to account for > > > leap seconds? > > > > 60, maybe --- I have not looked at the SQL spec. 61 is a widely > > repeated mistake; there never have been and never will be two leap > > seconds in the same minute (cf. NTP spec, RFC1305, esp. appendix E). > > But in reality, since we are using Unix-based timekeeping which does not > > cope with leap seconds, it is pointless to consider :60 as meaning a > > leap second. I think it's better to continue to regard it as an error. > > The only other thing we could do with it is treat 00:00:60 as meaning > > the same as 00:01:00, which is not really correct behavior. > Looking at Page 166 of "SQL-99 Complete, Really" by Peter Gulutzan & > Trudy Peltzer, R&D Books, ISBN 0-87930-568-1, 1st bullet: > > " First the Standard *REQUIRES* a DBMS to extend the range of > seconds-field values to ''less than 62'' (rather than ''less than > 60'') and thus account for up to 2 positive leap seconds. (There is a > GOTCHA here: leap seconds should always be for the last minute of a > day as in TIME '23:59:60', but the Standard allows erroneous values > like TIME '12:34:60'.)" Emphasis on requires is mine. > > So, here we have the SQL-99 standard requiring the behaviour. > > So, what do the assembled coders/experts think? Oh, and the UnixWare strftime man page allows %s to return 00-61. SO, we need to allow it as well. I suspect the C99 standard or some other POSIX/SUS/etc standard changed. So, we need to change. LER > > Larry > > > > > regards, tom lane > -- > Larry Rosenman http://www.lerctr.org/~ler > Phone: +1 972-414-9812 E-Mail: ler@lerctr.org > US Mail: 1905 Steamboat Springs Drive, Garland, TX 75044-6749 -- Larry Rosenman http://www.lerctr.org/~ler Phone: +1 972-414-9812 E-Mail: ler@lerctr.org US Mail: 1905 Steamboat Springs Drive, Garland, TX 75044-6749
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