Re: Index Skip Scan

Hi

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.

Looks like very interesting patch, and important for some BI platforms