[radiowave]

Excellent write-up. Thanks.

Has any thought been given to whether this query planner could be adapted (much further down the road, I'd guess) to support dynamic replanning? (That is, altering the plan mid-query, if it should be found that the row-count estimates were way off.)

[andydb]

We've talked about ideas along those lines. However, rather than altering the plan mid-query, we'd be more likely to have some kind of feedback mechanism that corrects estimates for the benefit of future plans.

Another commenter posted an interesting paper that's related to your question:

https://www.microsoft.com/en-us/research/uploads/prod/2018/0...

[radiowave]

Thanks, I'll check that out.