Re: multivariate statistics v14

On Wed, Mar 9, 2016 at 9:21 AM, Tomas Vondra
<tomas.vondra@2ndquadrant.com> wrote:
> Hi,
>
> On Wed, 2016-03-09 at 08:45 -0800, Jeff Janes wrote:
>> On Wed, Mar 9, 2016 at 7:02 AM, Tomas Vondra
>> <tomas.vondra@2ndquadrant.com> wrote:
>> > Hi,
>> >
>> > thanks for the feedback. Attached is v14 of the patch series, fixing
>> > most of the points you've raised.
>>
>>
>> Hi Tomas,
>>
>> Applied to aa09cd242fa7e3a694a31f, I still get the seg faults in make
>> check if I configure without --enable-cassert.
>
> Ah, after disabling asserts I can reproduce it too. And the reason why
> it fails is quite simple - clauselist_selectivity modifies the original
> list of clauses, which then confuses cost_qual_eval.
>
> Can you try if the attached patch fixes the issue? I'll need to rework a
> bit more of the code, but let's see if this fixes the issue on your
> machine too.

Yes, that fixes it.


>
>> With --enable-cassert, it passes the regression test.
>
> I wonder how can it work with casserts and fail without them. That's
> kinda exactly the opposite to what I'd expect ...

I too was surprised by that.  Maybe cassert makes a copy of some data
structure which is used in-place without cassert?

Thanks,

Jeff