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COMPUTER SOFTWARE APPLICATION - CITS

This cursor shows rows that were removed from the database after it was opened. A static cursor does not
represent any INSERT, UPDATE, or DELETE operations (unless the cursor is closed and reopened).
Dynamic Cursors

The dynamic cursors are opposite to the static cursors that allow us to perform the data updation, deletion, and
insertion operations while the cursor is open. It is scrollable by default. It can detect all changes made to the rows,
order, and values in the result set, whether the changes occur inside the cursor or outside the cursor. Outside the
cursor, we cannot see the updates until they are committed.
Forward-Only Cursors

It is the default and fastest cursor type among all cursors. It is called a forward-only cursor because it moves only
forward through the result set. This cursor doesn’t support scrolling. It can only retrieve rows from the beginning
to the end of the result set. It allows us to perform insert, update, and delete operations. Here, the effect of insert,
update and delete operations made by the user that affect rows in the result set are visible as the rows are fetched
from the cursor. When the row was fetched, we cannot see the changes made to rows through the cursor.
The Forward-Only cursors are three categorize into three types:
1 Forward_Only Keyset
2 Forward_Only Static
3 Fast_Forward

Keyset Driven Cursors
This cursor functionality lies between a static and a dynamic cursor regarding its ability to detect changes. It can’t
always detect changes in the result set’s membership and order like a static cursor. It can detect changes in the
result set’s rows values as like a dynamic cursor. It can only move from the first to last and last to the first row. The
order and the membership are fixed whenever this cursor is opened.

It is operated by a set of unique identifiers the same as the keys in the keyset. The keyset is determined by all
rows that qualified the SELECT statement when the cursor was first opened. It can also detect any changes to
the data source, which supports update and delete operations. It is scrollable by default.

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CITS : IT&ITES - Computer software application - Lesson 18 - 36