Comparing cursor vs. WHILE loop performance
Cursors Cursors are a looping construct built inside the database engine and come with a wide variety of features. Cursors allow you to fetch a set of data, loop through each record, and modify the values as necessary; then, you can easily assign these values to variables and perform processing on these values. Depending on the type of cursor you request, you can even fetch records that you’ve previously fetched. Because a cursor is an actual object inside the database engine, there is a little overhead involved in creating the cursor and destroying it. Also, a majority of cursor operations occur in tempdb, so a heavily used tempdb will be even more overloaded with the use of cursors. The types of cursors used are very important in terms of performance. Below is a list of the available cursor types as listed on FORWARD_ONLY Specifies that the cursor can only be scrolled from the first to the last row. FETCH NEXT is the only supported fetch option...
