Re: negative bitmapset member not allowed Error with partition pruning

On 27 July 2018 at 13:35, Amit Langote  wrote:
> On 2018/07/27 1:28, Tom Lane wrote:
>> (BTW, I'm not sure that it was wise to design bms_add_range to fail for
>> empty ranges.  Maybe it'd be better to redefine it as a no-op for
>> upper < lower?)
>
> FWIW, I was thankful that David those left those checks there, because it
> helped expose quite a few bugs when writing this code or perhaps that was
> his intention to begin with, but maybe he thinks differently now (?).

I think it's more useful to keep as a bug catcher, although I do
understand the thinking behind just having it be a no-op.

Partition pruning is complex code so I think additional caution is
warranted. People are more likely to notice the error and complain.
It's likely especially useful with tools like sqlsmith, as I imagine
it does not validate the actual results of queries (does it?). but I'm
pretty sure that the ERROR would get flagged up.

-- 
 David Rowley                   http://www.2ndQuadrant.com/
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