Re: EXPLAIN vs track_io_timing=on vs tests

Hi,

On 2020-10-29 16:10:37 -0700, Andres Freund wrote:
> I run my development instances with track_io_timing=on, as I've found
> that to be really useful. Unfortunately that causes tests to fail
> whenever I forget to turn that off to run installcheck.
>
> The diffs are caused by the additional data shown in the explain tests:
> ...
> - "Temp Written Blocks": N +
> + "Temp Written Blocks": N, +
> + "I/O Read Time": N.N, +
> + "I/O Write Time": N.N +
> ...
>
>
> First, why is the output of these fields conditional when using a
> non-text format? Seems we instead should output -1 or null. The latter
> seems a bit clearer, but is a bit json specific. I guess we could add a
> ExplainPropertyNull() or such?

Not addressed so far.

> Second, as long as it is conditional, would anybody mind if I put a
> track_io_timing=false into explain.sql? We don't try to make the tests
> pass with every possible option set, but track_io_timing seems common
> enough?

Done that now.

Greetings,

Andres Freund