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