Different types of cursors:
- These cursors are invoked implicitly.
- User need not create, open, fetch or close the cursor.
- These cursors are not invoked implicitly.
- User needs to create, open, fetch or close the cursor.
- Stores a complete copy of the result set.
- Used mostly where scrolling is required.
- Static cursors don’t support updates.
Forward - only cursors:
- This cursor supports updates but not scrolling.
- It supports only fetching serially.
- Rows are not retrieved from the database until they are fetched.
Forward - only cursors / Read only cursor:
- These are the fastest of the cursors and cannot be updated.
- They cannot be created on query that returns only read only columns.
Key set driven:
- It is a scrollable cursor that cannot be updated. These cursors are controlled by a set of physical identifiers called as key set.
- The keyset is built in a temporary table when the cursor is opened.