I have an issue with sql server not performing good when compared to old server. The problem is SQL Server is not using all the columns in the index making it fetch over 45 million rows as opposed to about 9000 rows. This makes query run for 16s.
We have an old server more than 3 years old with direct attached drives. The query takes less than a second. This server has 4 processors with 10 cores per processor.
We want to migrate to a new server, the new server has 4 procs with 12 cores with SAN storage. The same query here takes 13s. Same database, all indexes are re-indexed and statistics updated. Any thoughts will help.