Re: [sqlsmith] Failed to generate plan on lateral subqueries

On Sat, Dec 12, 2015 at 8:30 PM, Andreas Seltenreich <seltenreich(at)gmx(dot)de> wrote:
> I currently set statement_timeout to 1s to avoid wasting time letting
> postgres crunch numbers. Less than 0.5% of the queries run into this
> timeout.

I wonder if any of these timeouts would be interesting to look at.
Some may just be very large queries that will take a few seconds to
plan but others may be queries that are uncovering N^2 algorithms or
even conceivably loops that are not terminating.

When you hit the timeout is this implemented in your fuzzer or using
statement_timeout? If the former, can you add a statement_timeout of
just short of the timeout in the fuzzer and find cases where the
planner might not be calling CHECK_FOR_INTERRUPTS frequently enough?

> > Do you have coverage data for the corpus?
>
> I do have some older numbers for line coverage from before the recent grammar extension:

If you have a corpus of queries in a simple format it would be pretty
convenient to add them in a regression test and then run make coverage
to get html reports.

Did you publish the source already? I haven't been following all
along, sorry if these are all answered questions.

--
greg