Re: [Patch]Add tab completion for DELETE ... USING

Hi Fujii-san,

Thank you for your review!

> Would it be better to use "relations supporting SELECT" instead of
"selectables"?

Good point. I've updated the comment to use "relations supporting SELECT"
for consistency.

> As for the regression test, I agree with Kirill.

In my earlier discussion with Kirill, I argued that tests should be kept
since this patch implements a new feature.
However, I now understand that the existing tests already cover the
Query_for_list_of_selectables pattern,
so a separate test for DELETE ... USING would be redundant. I've removed
the test in the updated patch.

I've prepared a v5 patch with the following changes:
- Use "relations supporting SELECT" in the comment for consistency
- Remove the regression test

The updated v5 patch is attached.

Regards,
Tatsuya Kawata