Re: BRIN indexes - TRAP: BadArgument

Heikki Linnakangas wrote:
> On 10/07/2014 01:33 AM, Alvaro Herrera wrote:

> >I added an USE_ASSERTION-only block in brininsert that runs the union
> >support proc and compares the output with the one from regular addValue.
> >I haven't tested this too much yet.
>
> Ok, that's better than nothing. I wonder if it's too strict, though. It uses
> brin_tuple_equal(), which does a memcmp() on the tuples. That will trip for
> any non-meaningful differences, like the scale in a numeric.

True. I'm not real sure how to do better, though. For types that have
a btree opclass it's easy, because we can just use the btree equality
function to compare the values. But most interesting cases would not
have btree opclasses; those are covered by the minmax family of
opclasses.

> It would be wise to reserve some more support procedure numbers, for future
> expansion. Currently, support procs 1-4 are used by BRIN itself, and higher
> numbers can be used by the opclass. minmax opclasses uses 5-8 for the <, <=,
> >= and > operators. If we ever want to add a new, optional, support function
> to BRIN, we're out of luck. Let's document that e.g. support procs < 10 are
> reserved for BRIN.

Sure. I hope we never need to add a seventh optional support function ...

--
Álvaro Herrera http://www.2ndQuadrant.com/
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