Re: Assert in pageinspect with NULL pages

First of all, thanks for the review and remarks!

18.02.2022 08:02, Michael Paquier пишет:
> On Thu, Feb 17, 2022 at 05:40:41PM +0800, Julien Rouhaud wrote:
>> About the patch, it's incorrectly using a hardcoded 8192 block-size rather than
>> using the computed :block_size (or computing one when it's not already the
>> case).
> Well, the tests of pageinspect fail would already fail when using a
> different page size than 8k, like the checksum ones :)
>
> Anywa, I agree with your point that if this is not a reason to not
> make the tests more portable if we can do easily.

Fixed.

>> I'm also wondering if it wouldn't be better to return NULL rather than throwing
>> an error for uninitialized pages.
> Agreed that this is a sensible choice. NULL would be helpful for the
> case where one compiles all the checksums of a relation with a full
> scan based on the relation size, for example. All these behaviors
> ought to be documented properly, as well. For SRFs, this should just
> return no rows rather than generating an error.

So, I tried to implement this remark. However, further getting rid of
throwing an error and replacing it with a NULL return led to reproduce
the problem that Alexander Lakhin mentioned And here I need little more
time to figure it out.

And one more addition. In the previous version of the patch, I forgot to
add tests for the gist index, but the described problem is also relevant
for it.

--
Daria Lepikhova
Postgres Professional