I have a table called MailBox with 45 columns in my heavy OLTP database with around 3 million records (300GB in size). Users access this table very frequent with different search conditions. Now my problem is, our DBA has created too many indexes in this table. I found lot of indexes are duplicated as below,
1. Two indexes are same by Index Columns but different INCLUDED columns. I think this can be combined as one by collectively creating all INCLUDED column in the first index. Please suggest (with some reference)
2. Two indexes are same by Index Columns, INCLUDED columns but different Filter expression. Please suggest.
Also let me know, how indexes (if too many) causing DEADLOCKS.
Note: I want answers for the above questions, not alternative solutions.