Enable "fromNext" by default from druid-0.10.0

[navis]

Based on #2576. As discussed in #2576 (comment), enable "fromNext" by default from druid-0.10.0.

[fjy]

👍

[fjy]

@navis can we fix merge conflicts?

[nishantmonu51]

👍

[nishantmonu51]

@navis: can you fix conflicts ?

[gianm]

IMO, if we're going to change the default of fromNext, we should also make it mandatory to specify either fromNext: false or fromNext: true. This means that people that don't pass fromNext in their queries will get failures starting in 0.10.0, which I think is better than getting wrong results.

[gianm]

Hmm, actually, my comment was kind of nonsensical. There's no such thing as "changing the default" for something that's mandatory. I still think that silent wrong results on older client code is bad, but also, making fromNext mandatory is kind of silly.

I would be ok with adding a runtime property that controls the default behavior, like druid.query.select.fromNextDefault and have that default to "true" in 0.10.0. Then users that need to support older client code could set it to "false" to get the old Druid behavior.

The important thing, imo, is that many Druid deployers are not the same people as the ones that write the queries, and we have to recognize that dynamic when making changes like this.

@fjy @nishantmonu51 @navis what do you think?

[nishantmonu51]

@gianm: your suggestion seems good to me.

[fjy]

@gianm 👍

[jon-wei]

Closing this, discussion can continue at #3986