SQL command information

 1. Which is the subset of SQAL commands used to manipulate Oracle Database structures, including tables?

    Data Definition Language (DDL)

2. What operator performs patter matching?

    LIKE operator

3. What operator test column for the absence of data?

    IS NULL operator

4. Which command executes the contents of a specified file?

    START <filename> or @<filename>

5. What is the parameter substitution symbol used with INSERT INTO commands?

    &

6. Which command displays the SQL command in the SQL buffer, and then executes it?

    RUN

7. What are the wildcards used for pattern matching?

    _for single character substitution and % for multi-character substitution

8. State true or false. EXISTS, SOME, ANY are operators in SQL.

    true

9. State true or false, !=, < >, ^= all denote the same operation.

    True

10. What are the privileges that can be granted on a table by a user to others?

    Insert, update, delete, select, reference, index, execute, alter, all

11. What command is used to get back the privileges offered by the GRANT command?

    REVOKE

12. Which system tables contains information privileges granted and privileges obtained?

    USER_TAB_PRIVS_MADE, USER_TAB_PRIVS_RECD

13. Which system table contains information on constraints on all the tables created?

    USER_CONTRAINTS

14. TRUNCATE table emp;

    DELETE from emp;

    will the outputs of the above two commands differs?

    Both will result in deleting all the rows in the table EMP.

15. What is the difference between TRUNCATE and DELETE commands?

    TRUNCATE is a DDL command whereas DELETE is a DML command. Hence DELETE operation can be rolled back, but TRUNCATE operation cannot be rolled back.  WHERE clause can be used with DELETE and not with TRUNCATE.

16. What command is used to create a table by copying the structure of another table?

 CREATE TABLE .. AS SELECT command 

Explanation : 

To copy only the structure, the WHERE clause of the SELECT command should contains a FALSE statement as in the following. 

CREATE TABLE NEWTABLE AS SELECT * FROM EXISTINGTABLE WHERE 1=2;

If the WHERE condition is true, then all the rows or rows satisfying the condition will be copied to the new table.

17. What will be the output of the following query?

SELECT REPLACE(TRANSLATE(LTIM(RTRIM('!! ATHEN  !!', '!'), 'AN',  '**'), '*', 'TROUBLE') FROM DUAL;

18. What will be the output of the following query?

select decode(trasnslate('A', '1234567890',

Selenium Automation

Testing Guys please provide your valuable feedback, opinion on this blog spot. If you wish to share any new ideas,documentation on testing please your welcome.

Types of Testing

Types of Testing:

Unit testing: it is a white box testing conducted by developer. It is used to test most micro scale of testing to test particular function or code modules.

Unit: Smallest testable piece of software.
Unit testing done to show that the unit doesn’t satisfy the functional specification and /or its implemented structure doesn’t match the intended design structure.

Smoke Testing: it is used to test or validate the every basic functionality of the system.

Or

Smoke Testing: It is an initial type of testing once testing team gets a build needs to do the BVT (Build verification testing) or smoke testing for verifying the major functional component of the build. This has to be done based on the requirement.

Functional Testing: It is used to test each and every module is functionally stable entire module is tested by functional testing.

Regression Testing: testing to ensure that code changes have not had an adverse effect to the other module or an existing function.

Re -Testing: Testing in which one will perform testing on the same function again and again with multiples sets of data in order to come to a conclusion whether functionality is working fine or not.

Integration Testing: is the phase of software testing in which individual modules are combined and tested as a group. It follows unit testing and proceeds system testing.
Different types: big bang, top down, button-up.

System Testing: System is a big component.
Testing that attempts to discover defects that are properties of the entire rather than of its individual components.
Concern: Issues, behavior that can only be exposed by testing the entire integrated system (e.g. performance, security, recovery).

Stress Testing: Testing system functionality while the system is under unusually heavy or peak load. It is carried out at high stress environment. This requires that you make some prediction about expected load levels of your website.

Load Testing: Testing an application under heavy load such as the testing of a website under a range of loads to determine at what point the system response time degrades or fails.

Performance Testing: is conducted to indentify the operating condition where system exhibits the best response time.

Volume Testing: is done to find weakness in the system w.r.t its handling of large amount of data during short time periods.

Usability Testing: Usability means that system are easy and fast learn, efficient to use, easy to remember, cause no operating errors and offer a high degree of satisfaction for the user.
Usability means bringing the usage perspective into focus the side towards the user.

Security Testing: Testing how well system protects against unauthorized internal or external users will full damage etc… This type of testing may requires sophisticated testing techniques.

Alpha Testing: Testing of an application when development is nearly completion minor design changes may still be as result of such testing.
Typically done by end user or other not by programmers or testers.

Beta Testing: Testing when development and testing are essential completed and final bugs and problems need to found before final release. Typically done by end-user or other not by programmers.

UAT: Software is handed over to the user in order to find out, if the software meets the user expectation and work as it’s expected. This is the final testing conducted before the customer accepts the products.

Type of Architecture

Client server application/Web server application

Points: It is a network architecture which separates a client from a server.

• The client software can send request to a server.
• Server includes web server, application server, file server, terminal server and mail server.

Ex: if you are browsing an online store, your computer and web browser would be considered a client and the computer, data and application that make up the online store would be considered the server. When your web browser request a particular page from the online store, the server finds all of the information required to display the article in the database, assembles it into a web page and send it back to your web browser for you to look at.

Characteristics of a Server:
• Passive (slave)
• Waits for the request
• Upon receipts of request, processes them and then server’s replies.

Characteristics of a Client:
• Active (master)

• Sends request

• Waits for and receives server replies

Servers are two types,
• State full server and Stateless

A State less server does not keep any information b/w requests
A State full server can remember information b/w requests.
Ex: An HTTP server for static HTML pages is a stateless server,
While Apache Tomcat is an example of a state full server

The interaction b/w client & server are often described using sequence diagrams. It is a standardized in the UML (Unified Modular Language).

Peer to Peer Architecture: Is another types of network architecture because each node or instance of the program is both a client and a server and each has equivalent responsibilities.

Tiered Architecture: Generic client/server architecture has two types of nods on the network client and server. This is called as “two-tier architecture”.

Some network will consists of three different kinds o f nodes.

Client, application server, which process data for the client and data base server which store data for the application server. This is called 3 tier architecture.

Advantages of n-tier architecture with two tier architecture
1. It separates out the processing that occurs to better balance the load on the different server.
2. It is more scalable

Disadvantages:
1. It puts more loads on the network.
2. It is much more difficult to program and test software than in two-tier architecture because more devices have to communicate to complete a user’s transaction.

Thin client Vs thick client:
Thin client (sometimes also called lean client) is a client computer or client software in client server architecture network which depends primarily on the central server for processing activities and mainly focus on convening input and output b/w the user and the remote server.

Thick client or fat client server does as much processing as possible and passes only data for communications and storages to the server.

Environment:

Environment is a combination of 3 layers:
• Presentation Layer
• Business layer
• Data base layer

Types of Environment:
There are 4 types of environments:
1. Stand alone environment/ one-tier architecture
2. Client server environment/two-tier architecture
3. Distributed environment/ n- tier architecture

1. Stand alone environment (or) one tier architecture:
This environment contains all the three layer i.e. presentation layer, business layer, and data base layer single tier.

2. Client server environment or two tier architecture:
In this environment two tiers will be there one tier is for client and other tier is for database server. Presentation layer and business layer will be present in each and every client and the database will be present in database server.

3. Web environment: In this environment three tiers will be there client resides in one tier, application server resides in middle tier and database server resides in the last tier. Every client will have the presentation layer, application server will have the business layer and database server will have the database layer.

4. Distributed environment: it is same as the web environment but the business logic is distributed among application server is order to distribute the load.

Web server: It is software that provides web services to the client

Application server: It is server that holds the business logic.
Ex: Tomcat, web logic, web spear etc…

Comparison with the MVC architecture:
MVC – Model view controller

A fundamental rule in three tier architecture is the client – tier never communicates directly with the data tier in a three – tier model. All communication must pass through the middle ware tier.
The three tier architecture is linear. MVC is a triangle the view sends update to the controller, the controller updates the model and the view gets updated directly from the model.

Web development usage:
Three tiers are often used to refer to web sites.
1. A front end web servers serving static content.
2. A middle dynamic content processing and generation level application servers for ex: java EE platform.
3. A back end database, comprising both data sets and the database management system or RDBMS software that manager and provides access to the data.

Application and Web Servers:
Web server serves pages for viewing in a web browser, while an application server provides method that client application can call.

A web server exclusively handles HTTP request, whereas an application server serves business logic to applications programs through any number of protocols.

Testing Technique

Types of Testing Techniques:

1. Equivalence Partitioning
2. Boundary Value Analysis
3. Error Guessing.

Equivalence Partitioning: Dividing the input domain into classes of data for which test cases can be generated.

Equivalence Class: A portion of a component input or output domain for which the component behavior is assumed to be the same from the component specification.

Boundary Value Testing:
Boundary Testing: Test which focus on the boundary or limit condition of the software begins tested.

Boundary Value Analysis: BVA is similar to equivalence partitioning but focus on “cover –cases”, or values that are usually out of range as defined by the specification. This means that if a function expects all values is range of negative 100 to positive 1000, test input would include negative 101 & positive 1001.

Error Guessing:
In software testing, error guessing is a test method in which test cases used to find bugs in programs are established based on experience in prior testing. The scope of test cases usually rely on the software tester involved, who uses past experience and intuition to determine what situations commonly cause software failure, or may cause errors to appear. Typical errors include divide by zero, null pointers, or invalid parameters.


Error guessing has no explicit rules for testing; test cases can be designed depending on the situation, either drawing from functional documents or when an unexpected/undocumented error is found while testing operations.

Test Matrics

Test Matrices:

Test matrices accomplish is analyzing the current level of maturity in testing and give a projection on how to go about testing activities by allowing us to set goals and product future trends.

Table showed are some examples there are many test matrices.