Tuesday, February 23, 2010

Exams Mcse Mcp Microsoft Oracle Ocp Ccsa Ccse Solaris Dump Display


1. The number of cascading triggers is limited by which data base
initialization parameter?

a. CASCADE_TRIGGER_CNT
b. OPEN_CURSORS ****
c. OPEN_TRIGGERS
d. OPEN_DB_TRIGGERS

2. Which type of package construct must be declared both within the
package specifications and package body?

a. All package variables.
b. Boolean variables.
c. Private procedures and functions.
d. Public procedures and functions. ****

3. Why do stored procedures and functions improve performance?
(choose two)

a. They reduce network round trips. ****
b. They postpone PL/SQL parsing until run time. ****
c. They allow the application to perform high speed processing
locally.
d. They reduce the number of calls to the database and decrease
network traffic by bundling commands.
e. They reduce the number of calls to the database and decrease
network traffic by using the local PL/SQL engine.

4. When creating stored procedures and functions, which construct
allows you to transfer values to and from the calling environment?

a. Local variables.
b. Formal arguments. ****
c. Boolean variables.
d. Substitution variables.

5. You need to remove the database trigger, BUSINESS_RULE. Which
command do you use to remove the trigger in the SQL*Plus
environment?

a. DROP TRIGGER business_rule; ****
b. DELETE TRIGGER business_rule;
c. REMOVE TRIGGER business_rule;
d. ALTER TRIGGER business_rule;
e. DELETE FROM USER_TRIGGER
WHERE TRIGGER_NAME= ‘BUSINESS_RULE’;

6. Which two tables are fused track object dependencies?

a. USER_DEPENDENSIES. ****
b. USER_IDEPTREE.
c. IDEPTREE. ****
d. USER_DEPTREE.
e. USER_DEPENDS.

7. The QUERY_PRODUCT procedure directly references the product
table. There is a NEW_PRODUCT_VIEW view created based on the NOT
NULL columns of the table. The ADD_PRODUCT procedure updates the
table indirectly by the way of NEW_PRODUCT_VIEW view. Under which
circumstances does the procedureADD_PRODUCT get invalidated but
automatically get complied when invoked?

a. When the NEW_PRODUCT_VIEW is dropped.
b. When rows of the product table are updated through SQL Plus.
c. When the internal logic of the QUERY_PRODUCT procedure is
modified.
d. When a new column that can contain null values is added to the
product table. ****
e. When a new procedure is created that updates rows in the product
table directly.

8. You need to recompile several program units you have recently
modified through a PL/SQL program. Which statement is true?

a. You cannot recompile program units using a PL/SQL program.
b. You can use the DBMS_DDL. REOMPILE package procedure to recompile
the program units.
c. You can use the DBMS_ALTER. COMPILE packaged procedure to
recompile the program units.
d. You can use the DBMS_DDL.ALTER_COMPILE packaged procedure to
recompile the program units. ****
e. You can use the DBMS_SQL.ALTER_COMPILE packaged procedure to
recompile the program units.

9. Which type of argument passes a value from a calling environment?

a. VARCHER2
b. BOOLEAN
c. OUT ****
d. IN

10. You need to create a trigger on the EMP table that monitors
every row that is changed and places this information into the
AUDIT_TABLE. Which type of trigger do you create?

a. Statement-level trigger on the EMP table.
b. For each row trigger on the EMP table. ****
c. Statement-level trigger on the AUDIT_TABLE table.
d. For each row statement level trigger on the EMP table.
e For each row trigger on the AUDIT_TABLE table.

11. In order for you to create a run package, MAINTAIN_DATA, which
privilege do you need?

a. EXECUTE privilege on the MAINTAIN_DATA package. ****
b. INVOKE privilege on the MAINTAIN_DATA package.
c. EXECUTE privilege on the program units in the MAINTAIN_DATA
package.
d. Object privilege on all of the objects that the MAINTAIN_DATA
package is accessing.
e. Execute privilege on the program units inside the MAINTAIN_DATA
package and execute privilege on the MAINTAIN_DATA package.

12. You have created a script file EMP_PROC.SQL that holds text to
create a procedure, PROCESS_EMP. You have compiled the procedure for
the SQL Plus environment by running the script file EMP_PROC.SQL.
What happens if there are syntax errors in the procedure
PROCESS_EMP?

a. The errors are stored in the EMP_PROC.ERR file.
b. The errors are displayed to the screen when the script file is
run.
c. The errors are stored in the PROCEDURE_ERRORS data dictionary
view.
d. You need to issue the SHOWERRORS command in the SQL Plus
environment to see the errors. ****
e. You need to issue the DISPLAY ERRORS command in the SQL Plus
environment to see the errors.

13. Which statement about local dependent objects is true?

a. They are on different nodes.
b. They are in a different database.
c. They are on the same node in the same database. ****
d. They are on the same node in a different database.

14. You need to create a stored procedure that deletes rows from a
table. The name of the table from which the rows are to be deleted
is unknown until run time. Which method do you implement while
creating such a procedure?

a. Use SQL command DELETE in the procedure to delete the rows.
b. Use DBMS_SQL packaged routines in the procedure to delete the
rows. ****
c. Use DBMS_DML packaged routines in the procedure to delete the
rows.
d. Use DBMSDELETE packaged routines in the procedure to delete the
rows.
e. YOU cannot have a delete statement without providing a table name
before compile time.

15. Under which situation do you create a server-side procedure?

a. When the procedure contains no SQL statements.
b. When the procedure contains no PL/SQL commands.
c. When the procedure needs to be used by many client applications
accessing several remote databases.
d. When the procedure needs to be used by many users accessing the
same schema objects on a local database. ****

16. Examine this procedure:

CREATE OR REPLACE PROCEDURE ADD_PLAYER
(V_ID IN NUMBER, V_LAST_NAME VARCHER2)
IS
BEGIN
INSERT INTO PLAYER(ID,LAST_NAME).
VALUES(V_ID,V_LAST_NAME);
COMMIT;
END;

This procedure must invoke the UPD-STAT procedure and pass a
parameter. Which statement will successfully invoke this procedure?

a. EXECUTE UPD_BAT_STAT(V_ID);
b. UPD_BAT_STAT(V_ID); ****
c. RUN UPD_BAT_STAT(V_ID);
d. START UPD_BAT_STAT(V_ID);

17. Match the purity levels to their correct definitions:

Terms
RNTS
RNPS
WNDS
WNPS

Definitions
The function cannot modify the database tables.
The function cannot change the values of the package variables.
The function cannot query database tables.
The function cannot reference the value of public packaged
variables.

18. Examine this function:

CREATE OR REPLACE FUNCTION CALC_PLAYER_AVG
(V_ID in PLAYER_BAT_STAT. PLAYER_ID%TYPE)
RETURN NUMBER
IS
V_AVG NUMBER;
SELECTS HITS/AT_BATS
INTO V_AVG
FROM PLAYER_BAT_STAT
WHERE PLAYER_ID_V_ID;
RETURN(V_AVG);
END;

This function must be moved to a package. Which additional statement
must be added to the function to allow you to continue using the
function in the GROUP BY clause of a SELECT statement?

a. PRAGMA RESTRICT_REFERENCES (CALC_PLAYER_AVG, WNDS, WNPS); ****
b. PRAGMA RESTRICT_REFERENCES (CALC_PLAYER_AVG, WNPS);
c. PRAGMA RESTRICT_REFERENCES (CALC_PLAYER_AVG, RNPS, WNPS);
d. PRAGMA RESTRICT_REFERENCES (CALC_PLAYER_AVG, ALLOW_GROUP_BY);

19. A programmer develops a procedure, ACCOUNT_TRANSACTION, and has
left your company. You are assigned a task to modify this procedure.
You want to find all the program units invoking the
ACCOUNT_TRANSACTION procedure. How can you find this information?

a. Query the USER_SOURCE data dictionary view.
b. Query the USER_PROCEDURES data dictionary view.
c. Query the USER_DEPENDENCIES data dictionary views. ****
d. Set the SQL Plus environment variable trade code=true and run the
ACCOUNT_TRANSACTION procedure.
e. Set the SQL Plus environment variable DEPENDENCIES=TRUE and run
the Account_Transaction procedure.

20. Examine this package.

CREATE OR REPLACE PACKAGE BB_PACK
IS
V_MAX_TEAM_SALARY NUMBER(12,2);
PROCEDURE ADD_PLAYER(V_ID NUMBER,V_LAST_NAME
VARCHER2,V_SALARY NUMBER);
END BB_PACK;
/
CREATE OR REPLACE PACKAGE BODY BB_PACK
IS
PROCEDURE UPD_PLAYER_STAT
(V_ID IN NUMBER,V_AB_IN NUMBER DEFAULT4,V_HITS IN NUMBER)
IS
BEGIN
UPDATE PLAYER_BAT_STAT
SET AT_BATS+V_AB,
HITS=HITS+V_HITS
WHERE PLAYER_ID=V_ID;
COMMIT;
END UPD_PLAYER_STAT;
PROCEDURE ADD_PLAYER
(V_ID IN NUMBER,V_LAST_NAME VARCHER2,V_SALARY NUMBER)
IS
BEGIN
INSERT INTO PLAYER(ID,LAST_NAME,SALARY);
UPD_PLAYER_STAT(V_ID,0,0);
END ADD PLAYER;
END BB_PACK;

Which statement successfully assigns $75000000 to the
V_MAX_TEAM_SALARY variable from within a stand alone procedure?

a. V_MAX_TEAM_SALARY := 75000000;
b. BB_PACK.ADD_PLAYER. V_MAX_TEAM_SALARY := 75000000;
c. BB_PACK.V_MAX_TEAM_SALARY := 75000000; ****
d. This variable cannot be assigned a value from outside the
package.

21. Which two statements about the overloading feature of packages
are true?

a. Only local or packaged sub programs can be overloaded. ****
b. Overloading allows different functions with the same name that
differ only in their return types.
c. Overloading allows different subprograms with the same number,
type and order of the parameter.
d. Overloading allows different subprograms with the same name and
same number or type of the parameters.
e. Overloading allows different subprograms with the same name but
different in either number or type or order of parameters. ****


22. Examine this package:

CREATE OR REPLACE manag emps
IS
Tax_rate CONSTANT NUMBER(5,2):= . 28:,
V_id NUMBER;
PROCEDURE insert_emp(p-deptno NUMBER,p-sal NUMBER);
PROCEDURE delete_emp;
PROCEDURE update_emp:
FUNCTION calc_tax(o_sal NUMBER)
RETURN NUMBER;
END manag_emps;
/
CREATE REPLACE PACKAGE BODY manage_emps
IS
BEGIN
Update emp.
SET sal=|sal+p-raise_amt)+sal
WHERE empno= v_id;
END;
PROCEDURE insert_emp
(p_deptno NUMBER, p-sal NUMBER)
IS
BEGIN
INSERT INTO emp(empno, deptno,sal)
VALUES(v_id, p_deptno, p_sal);
END insert emp;
PROCEDURE delete_emp
IS
BEGIN
DELETE FROM emp
WHERE empno=v_id
END delete_emp;
PROCEDURE. Update_emp.
IS
V_sal NUMBER (10,2);
V_raise NUMBER(10,2);
BEGIN
SELECT Sal
INTO v_sal
FROM emp
WHERE empno=v_id;
IF v_sal<500>
V_raise:=0. 05;
ELSIF v_sal<1000>
V_raise:=0. 07;
ELSE
V_raise:=0. 04
END IF;
Update_sal(v_raise);
END update_emp.
FUNCTION calc_tax
(p_sal NUMBER)
RETURN NUMBER
IS
BEGIN
RETURN p_sal* tax-rate;
END calc_tax;
END MANAGE_emp;
/

What is the name of the private procedure in the package?

a. CALC_TAX
b. INSERT_EMP
c. UPDATE_SAL ****
d. DELETE_EMP
e. UPDATE_EMP
f. MANAGE_EMP

23. Examine the code:

CREATE OR REPLACE TRIGGER update_emp
AFTER UPDATE ON emp
BEGIN
INSERT INTO audit_table (who, audited)
VALUES(USER, SYSDATE);
END;

You issue an update command on the EMP table that results in
changing ten rows. How many rows are inserted into the AUDIT_TABLE?

a. 1 ****
b. 10
c. none
d. Value equal to the number of rows in the EMP table

24. All users currently have INSERT privileges on the PLAYER table.
You want only your users to insert into this table using the
ADD_PLAYER procedure. Which two actions must you take?

a. GRANT SELECT ON ADD_PLAYER TO PUBLIC;
b. GRANT EXECUTE ON ADD_PLAYER TO PUBLIC; ****
c. GRANT INSERT ON PLAYER TO PUBLIC;
d. GRANT EXECUTE, INSERT ON ADD_PLAYER TO PUBLIC;
e. REVOKE INSERT ON PLAYER FROM PUBLIC; ****

25. Which oracle supply package allows you to run jobs that use
defined times?

a. DBMS_JOB ****
b. DBMS_RUN
c. DBMS_PIPE
d. DBMS_SQL

26. You need to drop a table from within a stored procedure. How do
you implement this?

a. You cannot drop a table from a stored procedure.
b. Use the DROP command in the procedure to drop the table.
c. Use the DBMS_DDL packaged routines in the procedure to drop the
table.
d. Use the DBMS_SQL packaged routines in the procedure to drop the
table. ****
e. Use the DBMS_DROP packaged routines in the procedure to drop the
table.

27. Which data dictionary view gives you the names and the source
code of all the procedures you have created?

a. USER_SOURCE ****
b. USER_OBJECTS
c. USER_PROCEDURES
d. USER_SUBPROGRAMS

28. Examine this package:

CREATE OR REPLACE PACKAGE BB_PACK
IS
V_MAX_TEAM_SALARY NUMBER(12,2);
PROCEDURE ADD_PLAYER(V_ID IN NUMBER, V_LAST_NAME)
VARCHAR2(V_SALARY NUMBER);
END BB_PACK;
/
CREATE OR REPLACE PACKAGE BODY BB_PACK
IS
V_PLAYER_AVG NUMBER(4,3);
PROCEDURE UPD_PLAYER_STAT
V_ID IN NUMBER, V_AB IN NUMBER DEFAULT4, V_HITS IN NUMBER)
IS
BEGIN
UPDATE PLAYER_BAT_STAT
SET ADD_BAT=ADD_BATS+V_AB,
HITS=HITS+V_HITS
WHERE PLAYER_ID=V_ID;
COMMIT;
VALIDATE_PLAYER_STAT(V_ID);
END UPD_PLAYER_STAT;
PROCEDURE ADD_PLAYER
(V_ID IN NUMBER, V_LAST_NAME, VARCHAR2, V_SALARY IN NUMBER);
IS
BEGIN
INSERT INTO PLAYER (ID, LAST_NAME, SALARY)
VALUES(V_ID, V_LAST_NAME, V_SALARY);
UPD_PLAYER_STAT(V_ID,0,0);
END ADD_PLAYER;
END BB_PACK;

Which kind of packaged variable is V_MAX_TEAM_SALARY?

a. PRIVATE
b. PUBLIC ****
c. IN
d. OUT

29. Examine this trigger:

CREATE OR REPLACE TRIGGER UPD_TEAM_SALARY
AFTER INSERT OR UPDATE OR DELETE ON PLAYER
FOR EACH ROW
BEGIN
UPDATE TEAM
SET TOT_SALARY=TOT_SALARY+:NEW SALARY.
WHERE ID=:NEW:TEAM_ID;

You will be adding additional code later but for now you want the
current block to fire when updating the salary column. Which
solution should you use to verify that the user is performing an
update on the salary column?

a. ROW_UPDATE(‘SALARY’)
b. UPDATING(‘SALARY’) ****
c. CHANGING(‘SALARY’)
d. COLUMN_UPDATE(‘SALARY’)

30. Examine this package:

CREATE OR REPLACE PACKAGE discounts IS
G_ID NUMBER:=7839;
DISCOUNT_RATE NUMBER O. 00;
PROCEDURE DISPLAY_PRICE (V_PRICE NUMBER);
END DISCOUNTS;
/
CREATE OR REPLACE PACKAGE BODY discounts
IS
PROCEDURE DISPLAY_PRICE (V_PRICE_NUMBER)
IS
BEGIN DBMS_OUTPUT.PUT_LINE(‘DISCOUNTED||2_4
(V_PRICE*NVL(DISCOUNT_RATE, 1)))
END DISPLAY_PRICE;
BEGIN DISCOUNT_RATE;=0. 10;
END DISCOUNTS;
/

Which statement is true?

a. The value of DISCOUNT_RATE always remain 0.00 in a session.
b. The value of DISCOUNT_RATE is set to 0.10 each time the package
is invoked in a session.
c. The value of DISCOUNT_RATE is set to 1 each time the procedure
DISPLAY_PRICE is invoked.
d. The value of DISCOUNT_RATE is set to 0.10 when the package is
invoked for the first time in a session. ****

31. Examine this package:

CREATE OR REPLACE PACKAGE BB_PACK
V_MAX_TEAM_SALARY NUMBER(12,2);
PROCEDURE ADD_PLAYER(V_ID IN NUMBER, V_LAST_NAME
VARCHAR2, V_SALARY NUMBER);
DB_PACK;/ CREATE OR REPLACE PACKAGE BODY BB_PACK
IS
V_WHERE_AVG NUMBER(4,3);
PROCEDURE UPD_PLAYER_STAT
(V_ID IN NUMBER, V_AVG IN NUMBER DEFAULT 4,V_HITS IN NUMBER)
IS
BEGIN
UPDATE PLAYER_BAT_STAT
SET AT_BATS=AT_BATS+V_AB,
HITS=HITS+V_HITS
WHERE PLAYER_ID=V_ID;
COMMIT;
VALIDATE_PLAYER_STAT(V_ID);
END UPD_PLAYER_STAT;
PROCEDURE ADD-PLAYER
(V_ID IN NUMBER, V_LAST_NAME VARCHAR2, V_SALARY NUMBER)
IS
BEGIN
INSERT INTO PLAYER(ID, LAST_NAME, SALARY)
VALUES(V_ID, V_LAST_NAME, V_SALARY);
UPD_PLAYER_STAT(V_ID,0,0);
END ADD_PLAYER;
END BB_PACK;

An outside procedure VALIDATE_PLAYER_STAT is executed from this
package. What will happen when this procedure changes?

a. The package specification is dropped.
b. The package specification is invalidated.
c. The package is invalid to begin with.
d. The package body is invalidated ****

What is RDBMS?

In recent years, database management systems (DBMS) have established themselves as the primary means of data storage for information systems ranging from large commercial transaction processing applications to PC-based desktop applications. At the heart of most of today's information systems is a relational database management system (RDBMS). RDBMSs have been the workhorse for data management operations for over a decade and continue to evolve and mature, providing sophisticated storage, retrieval, and distribution functions to enterprise-wide data processing and information management systems. Compared to the file systems, relational database management systems provide organizations with the capability to easily integrate and leverage the massive amounts of operational data into meaningful information systems. The evolution of high-powered database engines such as Oracle7 has fostered the development of advanced "enabling" technologies including client/server, data warehousing, and online analytical processing, all of which comprise the core of today's state-of-the-art information management systems.

Examine the components of the term relational database management system. First, a database is an integrated collection of related data. Given a specific data item, the structure of a database facilitates the access to data related to it, such as a student and all of his registered courses or an employee and his dependents. Next, a relational database is a type of database based in the relational model; non-relational databases commonly use a hierarchical, network, or object-oriented model as their basis. Finally, a relational database management system is the software that manages a relational database. These systems come in several varieties, ranging from single-user desktop systems to full-featured, global, enterprise-wide systems, such as Oracle7.

This blog discusses the basic elements of a relational database management system, the relational database, and the software systems that manage it. Also included is a discussion of nonprocedural data access. If you are a new user to relational database technology, you'll have to change your thinking somewhat when it comes to referencing data nonprocedurally.

The Relational Database Model

Most of the database management systems used by commercial applications today are based on one of three basic models: the hierarchical model, the network model, or the relational model. The following sections describe the various differences and similarities of the models.

Hierarchical and Network Models


The first commercially available database management systems were of the CODASYL type, and many of them are still in use with mainframe-based, COBOL applications. Both network and hierarchical databases are quite complex in that they rely on the use of permanent internal pointers to relate records to each other. For example, in an accounts payable application, a vendor record might contain a physical pointer in its record structure that points to purchase order records. Each purchase order record in turn contains pointers to purchase order line item records.

The process of inserting, updating, and deleting records using these types of databases requires synchronization of the pointers, a task that must be performed by the application. As you might imagine, this pointer maintenance requires a significant amount of application code (usually written in COBOL) that at times can be quite cumbersome.

Elements of the Relational Model


Relational databases rely on the actual attribute values as opposed to internal pointers to link records. Instead of using an internal pointer from the vendor record to purchase order records, you would link the purchase order record to the vendor record using a common attribute from each record, such as the vendor identification number.

Although the concepts of academic theory underlying the relational model are somewhat complex, you should be familiar with are some basic concepts and terminology. Essentially, there are three basic components of the relational model: relational data structures, constraints that govern the organization of the data structures, and operations that are performed on the data structures.

Relational Data Structures

The relational model supports a single, "logical" structure called a relation, a two-dimensional data structure commonly called a table in the "physical" database. Attributes represent the atomic data elements that are related by the relation. For example, the Customer relation might contain such attributes about a customer as the customer number, customer name, region, credit status, and so on.


Key Values and Referential Integrity


Attributes are grouped with other attributes based on their dependency on a primary key value. A primary key is an attribute or group of attributes that uniquely identifies a row in a table. A table has only one primary key, and as a rule, every table has one. Because primary key values are used as identifiers, they cannot be null. Using the conventional notation for relations, an attribute is underlined to indicate that it is the primary key of the relation. If a primary key consists of several attributes, each attribute is underlined.

You can have additional attributes in a relation with values that you define as unique to the relation. Unlike primary keys, unique keys can contain null values. In practice, unique keys are used to prevent duplication in the table rather than identify rows. Consider a relation that contains the attribute, United States Social Security Number (SSN). In some rows, this attribute may be null in since not every person has a SSN; however for a row that contains a non-null value for the SSN attribute, the value must be unique to the relation.

Linking one relation to another typically involves an attribute that is common to both relations. The common attributes are usually a primary key from one table and a foreign key from the other. Referential integrity rules dictate that foreign key values in one relation reference the primary key values in another relation. Foreign keys might also reference the primary key of the same relation. Figure illustrates two foreign key relationships.



Oracle and Client/Server


Oracle Corporation's reputation as a database company is firmly established in its full-featured, high-performance RDBMS server. With the database as the cornerstone of its product line, Oracle has evolved into more than just a database company, complementing its RDBMS server with a rich offering of well-integrated products that are designed specifically for distributed processing and client/server applications. As Oracle's database server has evolved to support large-scale enterprise systems for transaction processing and decision support, so too have its other products, to the extent that Oracle can provide a complete solution for client/server application development and deployment. This chapter presents an overview of client/server database systems and the Oracle product architectures that support their implementation.

An Overview of Client/Server Computing

The premise of client/server computing is to distribute the execution of a task among multiple processors in a network. Each processor is dedicated to a specific, focused set of subtasks that it performs best, and the end result is increased overall efficiency and effectiveness of the system as a whole. Splitting the execution of tasks between processors is done through a protocol of service requests; one processor, the client, requests a service from another processor, the server. The most prevalent implementation of client/server processing involves separating the user interface portion of an application from the data access portion.

On the client, or front end, of the typical client/server configuration is a user workstation operating with a Graphical User Interface (GUI) platform, usually Microsoft Windows, Macintosh, or Motif. At the back end of the configuration is a database server, often managed by a UNIX, Netware, Windows NT, or VMS operating system.

Client/server architecture also takes the form of a server-to-server configuration. In this arrangement, one server plays the role of a client, requesting database services from another server. Multiple database servers can look like a single logical database, providing transparent access to data that is spread around the network.

Designing an efficient client/server application is somewhat of a balancing act, the goal of which is to evenly distribute execution of tasks among processors while making optimal use of available resources. Given the increased complexity and processing power required to manage a graphical user interface (GUI) and the increased demands for throughput on database servers and networks, achieving the proper distribution of tasks is challenging. Client/server systems are inherently more difficult to develop and manage than traditional host-based application systems because of the following challenges:

The components of a client/server system are distributed across more varied types of processors. There are many more software components that manage client, network, and server functions, as well as an array of infrastructure layers, all of which must be in place and configured to be compatible with each other.

The complexity of GUI applications far outweighs that of their character-based predecessors. GUIs are capable of presenting much more information to the user and providing many additional navigation paths to elements of the interface.

Troubleshooting performance problems and errors is more difficult because of the increased number of components and layers in the system.

Databases in a Client/Server Architecture

Client/server technologies have changed the look and architecture of application systems in two ways. Not only has the supporting hardware architecture undergone substantial changes, but there have also been significant changes in the approach to designing the application logic of the system.

Prior to the advent of client/server technology, most Oracle applications ran on a single node. Typically, a character-based SQL*Forms application would access a database instance on the same machine with the application and the RDBMS competing for the same CPU and memory resources. Not only was the system responsible for supporting all the database processing, but it was also responsible for executing the application logic. In addition, the system was burdened with all the I/O processing for each terminal on the system; each keystroke and display attribute was controlled by the same processor that processed database requests and application logic.

Client/server systems change this architecture considerably by splitting all of the interface management and much of the application processing from the host system processor and distributing it to the client processor.

Combined with the advances in hardware infrastructure, the increased capabilities of RDBMS servers have also contributed to changes in the application architecture. Prior to the release of Oracle7, Oracle's RDBMS was less sophisticated in its capability to support the processing logic necessary to maintain the integrity of data in the database. For example, primary and foreign key checking and enforcement was performed by the application. As a result, the database was highly reliant on application code for enforcement of business rules and integrity, making application code bulkier and more complex. Figure 2.1 illustrates the differences between traditional host-based applications and client/server applications. Client/server database applications can take advantage of the Oracle7 server features for implementation of some of the application logic.