The production database where I work is very large. There are roughly less than 10 tables that are taking up 90% of the database size.
One table is roughly 25 gig in size and the indexes on this one table are 132 gig! Roughly 44,415,774 rows, 121 columns and 48 indexes. All the indexes are non-unique and non-clustered.
There are what appears to be several overlapping indexes. Example:
Index 1: DueDate
Index 2: WCNum
Index 3: composite that is DueDate + WCNum.
For my own knowledge, would the composite DueDate + WCNum still cover queries filtered by DueDate or WCNum only? Are all 3 indexes truly needed or would the composite cover all there scenarios?