Hi Pavel, On 10/9/18 9:42 AM, Pavel Stehule wrote:
I tested last patch and I have some notes:1. postgres=# explain select distinct a10000 from foo; +-------------------------------------------------------------------------------------------+ | QUERY PLAN | +-------------------------------------------------------------------------------------------+ | Unique (cost=0.43..4367.56 rows=9983 width=4) | | -> Index Skip Scan using foo_a10000_idx on foo (cost=0.43..4342.60 rows=9983 width=4) | +-------------------------------------------------------------------------------------------+ (2 rows) In this case Unique node is useless and can be removed 2. Can be nice COUNT(DISTINCT support) similarly like MIN, MAX suppport 3. Once time patched postgres crashed, but I am not able to reproduce it.
Please, send that query through if you can replicate it. The patch currently passes an assert'ed check-world, so your query clearly triggered something that isn't covered yet.
Looks like very interesting patch, and important for some BI platforms
Thanks for your review ! Best regards, Jesper
