Re: [PoC] Improve dead tuple storage for lazy vacuum

On Wed, Mar 13, 2024 at 8:05 PM John Naylor <johncnaylorls(at)gmail(dot)com> wrote:
>
> On Wed, Mar 13, 2024 at 8:39 AM Masahiko Sawada <sawada(dot)mshk(at)gmail(dot)com> wrote:
>
> > As I mentioned above, if we implement the test cases in C, we can use
> > the debug-build array in the test code. And we won't use it in AND/OR
> > operations tests in the future.
>
> That's a really interesting idea, so I went ahead and tried that for
> v71. This seems like a good basis for testing larger, randomized
> inputs, once we decide how best to hide that from the expected output.
> The tests use SQL functions do_set_block_offsets() and
> check_set_block_offsets(). The latter does two checks against a tid
> array, and replaces test_dump_tids().

Great! I think that's a very good starter.

The lookup_test() (and test_lookup_tids()) do also test that the
IsMember() function returns false as expected if the TID doesn't exist
in it, and probably we can do these tests in a C function too.

BTW do we still want to test the tidstore by using a combination of
SQL functions? We might no longer need to input TIDs via a SQL
function.

> Funnily enough, the debug array
> itself gave false failures when using a similar array in the test
> harness, because it didn't know all the places where the array should
> have been sorted -- it only worked by chance before because of what
> order things were done.

Good catch, thanks.

> I squashed everything from v70 and also took the liberty of switching
> on shared memory for tid store tests. The only reason we didn't do
> this with the radix tree tests is that the static attach/detach
> functions would raise warnings since they are not used.

Agreed to test the tidstore on shared memory.

Regards,

--
Masahiko Sawada
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