Re: SQL float types
От | Peter Eisentraut |
---|---|
Тема | Re: SQL float types |
Дата | |
Msg-id | Pine.LNX.4.21.0007072138550.587-100000@localhost.localdomain обсуждение исходный текст |
Ответ на | Re: SQL float types (Tom Lane <tgl@sss.pgh.pa.us>) |
Ответы |
Re: SQL float types
Re: SQL float types |
Список | pgsql-hackers |
Tom Lane writes: > > float4 => real > > float8 => double precision > Not just on your say-so. Arguments please? SQL: 22)REAL specifies the data type approximate numeric, with implementation- defined precision. 23)DOUBLE PRECISION specifies the data type approximate numeric, with implementation-defined precision that is greaterthan the implementation-defined precision of REAL. Notice that there is no "at least" here anywhere. > In the absence of pretty compelling reasons to change, I think > "backwards compatibility" will have to win the day on something like > this. The REAL data type is not even documented. I'm evidently trying to get people to think in terms of standard types rather than the internal, low-level sounding names, but that won't work if the standard types aren't really standard and the internal types don't have a standard equivalent. Actually, if you read into the release history it says: SQL standard-compliance (the following details changes that makes postgres95 more compliant to the SQL-92 standard):* the following SQL types are now built-in: smallint, int(eger), float,real, char(N), varchar(N), date and time. The following are aliases to existing postgres types: smallint-> int2 integer, int -> int4 float, real -> float4 char(N) and varchar(N) are implementedas truncated text types. In addition, char(N) does blank-padding. So if you take that as documentation then my suggestion counts as a bug fix. :-) -- Peter Eisentraut Sernanders väg 10:115 peter_e@gmx.net 75262 Uppsala http://yi.org/peter-e/ Sweden
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