

As with is used to open a cursor variable whose query was bound to it when it was declared. A list of actual argument value expressions must appear if and only if the cursor was declared to take arguments. The query plan for a bound cursor is always considered cacheable; there is no equivalent of , as the cursor's scrolling behavior was already determined.
The cursor provides the functionality to iterate through a query result row-by-row. Note: Avoid using cursors when it is possible to express the same logic with SQL.
You should do this as cursors cannot be optimized the same way SQL can.
DECLARE CURSOR c1 IS SELECT * FROM test6; rec_cur c1%rowtype; BEGIN OPEN c1; LOOP FETCH c1 INTO rec_cur; EXIT WHEN c1%notfound; UPDATE test SET fk = rec_, fill = rec_WHERE pk = rec_cur.pk; END LOOP; CLOSE C1; END; / This is the simplest PL/SQL method and very common in hand-coded PL/SQL applications.
Rather than executing a whole query at once, it is possible to set up a cursor that encapsulates the query, and then read the query result a few rows at a time.
One reason for doing this is to avoid memory overrun when the result contains a large number of rows.
(However, loops automatically use a cursor internally to avoid memory problems.) A more interesting usage is to return a reference to a cursor that a function has created, allowing the caller to read the rows.
If you're performing an INSERT/UPDATE/DELETE, again, be sure to use the explicit transactions to vastly reduce the load on your log file by committing per loop, which prevents huge rollbacks in the case of failure.
What I love about writing SQL Tuning articles is that I very rarely end up publishing the findings I set out to achieve. We have a table containing years worth of data, most of which is static; we are updating selected rows that were recently inserted and are still volatile. For the purposes of the test, we will assume that the target table of the update is arbitrarily large, and we want to avoid things like full-scans and index rebuilds.
A cursor is a set of rows together with a pointer that identifies a current row.
Series of Interview questions to brushup your skills In this example we will learn – How to use CURSOR in HANA.