Re: [BUGS] 7.4: CHAR padding inconsistency

Added to TODO:

Make LENGTH() of CHAR() not count trailing spaces

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Tom Lane wrote:
> Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us> writes:
> > Well, that certainly is interesting. Oracle and MS-SQL preserve the
> > trailing space when concatenating. Does anyone remember the logic for
> > trimming space with ||?
>
> "trimming space with ||" is a completely inaccurate description of
> what's happening.
>
> 7.4 trims spaces from char(n) data when converting it to text (or
> varchar). Since we don't have a bpchar version of ||, only a text
> version, the implicitly invoked conversion is what's making the
> difference.
>
> AFAICS the Oracle and SQL Server behaviors are at least as inconsistent
> as our own. If trailing spaces are significant during concatenation,
> why aren't they significant to LENGTH()? I can't see a justification
> in the SQL spec for handling one case differently from the other.
>
> Actually the SQL spec is pretty inconsistent itself. It's clear that
> trailing spaces are insignificant in comparisons, if you are using a
> PAD SPACE collation which I think is the implication of CHAR(n), but
> I don't see anything that says that they are insignificant for other
> purposes such as LENGTH() and concatenation.
>
> I'd agree with changing bpcharlen() to not count trailing spaces,
> I think. That would be consistent with ignoring them in other contexts.
>
> regards, tom lane
>
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