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#1
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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 (AT) cri (DOT) ensmp.fr |
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---------------------------(end of broadcast)--------------------------- TIP 8: explain analyze is your friend |
#2
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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 (AT) cri (DOT) ensmp.fr |
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---------------------------(end of broadcast)--------------------------- TIP 8: explain analyze is your friend |
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