Recursion versus iteration, PL-SQL Programming

Assignment Help:

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

FUNCTION fib (n POSITIVE) RETURN INTEGER IS

pos1 INTEGER := 1;

pos2 INTEGER := 0;

cum INTEGER;

BEGIN

IF (n = 1) OR (n = 2) THEN

RETURN 1;

ELSE

cum := pos1 + pos2;

FOR i IN 3..n LOOP

pos2 := pos1;

pos1 := cum;

cum := pos1 + pos2;

END LOOP;

RETURN cum;

END IF;

END fib;

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.


Related Discussions:- Recursion versus iteration

Use tsql function sql server 2012, I want someone to write a TSQL function ...

I want someone to write a TSQL function that returns the name of the ODBC DSN. I will use the queries below, to get information about the connection, but none of these return th

Write a pl-sql program using the implicit cursor, Question: a) Given th...

Question: a) Given the following relation: Location(loc_id, bldg_code, room, capacity) The underlined field is a primary key. (i) Write a PL/SQL program using the impl

Delimiters, Delimiters A delimiter is a simple or compound symbol whi...

Delimiters A delimiter is a simple or compound symbol which has a special meaning to PL/SQL. For example, you use delimiters to symbolize an arithmetic operation like additio

Appgen to sap data export, We are seeking a freelance consultant that is fa...

We are seeking a freelance consultant that is familiar with Appgen applications. We require exporting all our data into a format appropriate for importing into SAP Business One. Pl

Sql pseudocolumns, SQL Pseudocolumns The PL/SQL recognizes the followin...

SQL Pseudocolumns The PL/SQL recognizes the following SQL pseudocolumns, that returns the specific data items: LEVEL, NEXTVAL, CURRVAL, ROWID, & ROWNUM. The Pseudocolumns are n

Using forall and bulk collect - bulk bind performance, Using FORALL and BUL...

Using FORALL and BULK COLLECT Together You can unite the BULK COLLECT clause with the FORALL statement, in that case, the SQL engine bulk-binds column values incrementally. In

Structure of an object type in pl/sql, Structure of an Object Type: Si...

Structure of an Object Type: Similar to package, an object type has 2 parts: the specification and the body. The specification is the interface to your applications; it declar

Recursion, Recursion The Recursion is a powerful method for simplify th...

Recursion The Recursion is a powerful method for simplify the design of the algorithms. Principally, the recursion means the self-reference. In the recursive mathematical serie

Between operator-comparison operators, BETWEEN Operator The operator BET...

BETWEEN Operator The operator BETWEEN, tests whether the value lies in a specified series. That means "greater than or equivalent to low value and less than or equivalent to hig

Data types in sql - timestamp, Data Types in SQL - Timestamp TIMESTAMP...

Data Types in SQL - Timestamp TIMESTAMP for values representing points in time on a specified uniform scale. DATE is used for timestamps on a scale of one day, such as DATE '2

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

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!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd