Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Recursion versus Iteration
Dissimilar the iteration, recursion is not crucial to PL/SQL programming. Any problem which can be solved using recursion can be solving using the iteration. Also, the iterative version of the subprogram is typically easier to design than the recursive version. Though, the recursive version is typically simpler, smaller, and hence easier to debug. Compare the functions below that calculate the nth Fibonacci number:
-- recursive version
FUNCTION fib (n POSITIVE) RETURN INTEGER IS
BEGIN
IF (n = 1) OR (n = 2) THEN
RETURN 1;
ELSE
RETURN fib(n - 1) + fib(n - 2);
END IF;
END fib;
-- iterative version
pos1 INTEGER := 1;
pos2 INTEGER := 0;
cum INTEGER;
cum := pos1 + pos2;
FOR i IN 3..n LOOP
pos2 := pos1;
pos1 := cum;
END LOOP;
RETURN cum;
The recursive version of the Fibonacci is more graceful than the iterative version. Though, the iterative version is more accurate; it runs faster and uses less storage. That is as each recursive call needs an additional time and memory. As the number of recursive calls gets bigger, so does the difference in effectiveness. Still, if you expect the number of recursive calls to be little, you may choose the recursive version for its readability.
UNION ALL - SQL Further varieties of UNION arise when we replace the key word DISTINCT by ALL in any of the foregoing examples, as in Example. ALL specifies that if row r appe
Interesting properties of CROSS JOIN - SQL Compare these with the "interesting properties of JOIN", CROSS JOIN is associative but not commutative. Unlike JOIN and NATURAL JOI
Example of WHEN or THEN Constraints A concrete example showing how SQL supports WHEN/THEN constraints CREATE TABLE SAL_HISTORY (EmpNo CHAR (6), Salary INTEGER NOT NULL,
Using ROLLBACK The ROLLBACK statements end the present transaction and undo any change made during the transaction. The Rolling back is helpful for two reasons. Firstly, if yo
Keyword and Parameter Description: label_name: This is an undeclared identifier which labels an executable statement or the PL/SQL block. You can use a GOTO statement to
Using EXTEND To enlarge the size of a collection, use EXTEND. This process has 3 forms. The EXTEND appends one null element to a collection. And the EXTEND(n) appends n null e
1.( /5 marks) Suppose that a B+-tree index with the search key (dept_name, building) is available on relation department. What would be the best way to handle the following selecti
to write a heap sort program usin pl-sql
Pass the nulls to a dynamic SQL: Passing Nulls: Assume that you want to pass the nulls to a dynamic SQL statement. For illustration, you may write the EXECUTE IMMEDIATE
Need Windows and Linux system Administrator We are seeking a part time system administrator to take care of our servers. Your things to do would add, but not limited to: -
Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd