Re: [PATCHES] commit TO_CHAR()

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От Karel Zak - Zakkr
Тема Re: [PATCHES] commit TO_CHAR()
Дата
Msg-id Pine.LNX.3.96.1000126200350.9764A-100000@ara.zf.jcu.cz
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On Wed, 26 Jan 2000, Peter Eisentraut wrote:

> Couldn't this be reduced to functions for timestamp, int4, int8, float8,
> and numeric?

With datetime/timestamp I not sure, exapmle date_part() exist for both.
And how is it with year in timestamp? 

test=> select '15000-01-26 21:01:57+01'::timestamp;?column?
----------invalid
(1 row)

test=> select '15000-01-26 21:01:57+01'::datetime;        ?column?
---------------------------Sun Jan 26 20:01:57 15000
(1 row)


Now is to_char's timestamp implementation very easy/terrible:
text *timestamp_to_char(time_t dt, text *fmt){        return datetime_to_char( timestamp_datetime(dt), fmt);}

:-) it call my classic datetime to_char(). I want rewrite it (and delete 
datetime version?), if I will certain with timestamp and timestamp to
'tm' struct conversion.  


Use float8's to_char only:

The to_char() convert it to string itself and must check float number 
range (FLT_DIG ..etc) and it is different for float4 and float8, but 
don't worry it is only 50 row in C. Yes, float4->float8 cast can make 
PG parser, but it is effective if you not need float8? IMHO this solution
reduce function/code, but not reduce performance/memory.   

(I re-send this mail to hacker list)                    Karel



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