Hello,
My 9.4 database is used as datawharehouse. I can't change the queries generated.
first index : INDEX COL (A,B,C,D,E)
In case of query based on COL A, the query planner sometimes go to a seq scan instead of using the first composite index.
The solution is to add a second indexe (redondant)
second index : INDEX COL (A)
In case of query based on COL A, B, C, D, (without E) as well, it doesn't uses the first index and prefers a seq scan.
I could create a third indexe :
first index : INDEX COL (A,B,C,D)
But I hope there is an other solution for that (table is huge).
It seems that the malus for using composite indexes is high.
Question is : is there a way to make the composite index more attractive to query planner ? (idealy equivalent to mono column indexe)
Thanks by advance