Re: GSoC 2017 weekly progress reports (week 2)

On Tue, Jun 13, 2017 at 1:02 PM, Andrew Borodin <borodin(at)octonica(dot)com> wrote:
> 2017-06-13 18:00 GMT+05:00 Shubham Barai <shubhambaraiss(at)gmail(dot)com>:

> Good job!

+1! :-)

> So, in current HEAD test predicate_gist_2.spec generate false
> positives, but with your patch, it does not?

Keep in mind, that false positives do not break *correctness* of serializable
transactions as long as it involves another transaction. (It *would* be a bug
if a transaction running alone could cause a serialization failure.) A false
*negative* is always a bug.

That said, false positives hurt performance, so we should keep the rate as low
as practicable.

> I'd suggest keeping spec tests with your code in the same branch, it's
> easier.

+1

> Also it worth to clean up specs style and add some words to
> documentation.

+1

> Kevin, all, how do you think, is it necessary to expand these tests
> not only on Index Only Scan, but also on Bitmap Index Scan? And may be
> KNN version of scan too?
> I couldn't find such tests for B-tree, do we have them?

Off-hand, I don't know. It would be interesting to run regression tests with
code coverage and look at the index AMs.

https://www.postgresql.org/docs/9.6/static/regress-coverage.html

--
Kevin Grittner
VMware vCenter Server
https://www.vmware.com/