What are Cursor ? Explain Different type of Cursor and its Disadvantage and how can i avoid Cursor

Cursor allow row-by row processing of the resultset

Type of Cursor:Static, Dynamic,Forward-only, Keyset-Driven

Disadvantage:Each time you fetch a row from the cursor, it results in a network roundtrip where as a select query makes only one roundtrips. however large the resultset is.Cursor are also costly because they requires more resources and temporary storage(results in more input output operation)