How can I improve performance of an Update Query? The query is as follows (with table and column names changed): UPDATE MyTable SET MyTime = 'Aug 25 2011 9:00AM' WHERE My_id = 'ABC1234' AND MyTime IS NULL The table has a few million records, and the query is updating a few thousand. The query completes in about 10s. The number of logical reads is in tens of thousands. I’ve added an index on MyTime, MyId hoping that the read part of the update will be much quicker. I think it now is, but the number of reads is still high and now the query causes an index update as well (so still a slow query). Note: SQL 2005 here, no filtered indexes. The query is executed about once per hour. So it takes data from HD instead of RAM every time. How can I improve the performance of the update query? Many Thanks.