Re: new heapcheck contrib module

Alvaro Herrera <alvherre(at)2ndquadrant(dot)com> writes:
> On 2020-May-14, Robert Haas wrote:
>> If you mean that we shouldn't have the buildfarm run the proposed heap
>> corruption checker against heap pages full of randomly-generated
>> garbage, I tend to agree. Such a test wouldn't be very stable and
>> might fail in lots of low-probability ways that could require
>> unreasonable effort to find and fix.

> This is what I meant. I was thinking of blocks generated randomly.

Yeah, -1 for using random data --- when it fails, how you gonna
reproduce the problem?

>> If you mean that we shouldn't have the buildfarm run the proposed heap
>> corruption checker against any corrupted heap pages at all, I tend to
>> disagree.

> Yeah, IMV those would not be arbitrarily corrupted -- instead they're
> crafted to be corrupted in some specific way.

I think there's definitely value in corrupting data in some predictable
(reproducible) way and verifying that the check code catches it and
responds as expected. Sure, this will not be 100% coverage, but it'll be
a lot better than 0% coverage.

regards, tom lane