It does not preserve order, which can lead to the Halloween problem as illustrated in script 4.Fetch statements are made on the underlying base tables, based on the key data cached in tempdb, but the key data is refreshed with each modification to key data on the base tables. A FAST_FORWARD cursor provides optimal performance but only supports the NEXT argument, which only fetches the next row.For most cursor types, key data is brought into memory and the cursor navigates this key data on a row-by-row basis; similar to the window washer going floor by floor.Trends come and go, but your DB strategy shouldn’t be a flavor of the month.The KEYSET cursor is implemented by copying primary key data into tempdb.
Cursor options There are four sets of cursor options: The STATIC cursor copies the data in the results set into tempdb and DML that occurs in the underlying results fails to reflect in the cursor's data.
As the result, Oracle created PL/SQL cursor to provide these extensions.
A PL/SQL cursor is a pointer that points to the result set of an SQL query against database tables.
Summary: in this tutorial, we will introduce you to PL/SQL cursor.
You will learn step by step how to use a cursor to loop through a set of rows and process each row individually.