Re: possible minor EXPLAIN bug?

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От Tom Lane
Тема Re: possible minor EXPLAIN bug?
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Msg-id 20052.1219155902@sss.pgh.pa.us
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Ответ на possible minor EXPLAIN bug?  ("Pavel Stehule" <pavel.stehule@gmail.com>)
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"Pavel Stehule" <pavel.stehule@gmail.com> writes:
> I thing so Agg node doesn't set width well:

The planner doesn't really bother to set the width correctly for any
expression-computing node.  This is partly laziness, but OTOH it is
very hard to estimate a sane width for any function returning a
variable-width data type; eg what are the odds of a useful answer forselect repeat(textcol, intcol) from tab1;
For plan nodes that return just Vars it's easier, since we generally
have got stats about average column widths.

I think Agg just copies the width of its input ...
        regards, tom lane


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