Database Interview Questions

An ontology refers to a model that contains a set of classes (individuals) plus a set of relations between them. Lets consider a relational database model, having three tables: Human, Man, Woman. As ...

UPI stands for Unique Primary Key, which constrain us to have unique keys, thus unique rows. Now even if the Multiset table allows duplicate rows by definition, the UPI constraint overrules it.

Answer: No.

Yes to store excel file in data base just you have to save the excel file in .CSV(comma delimiter) format and then insert the value as usually in database.....

Here is the query to export data into csv file.

Code
SELECT *
INTO OUTFILE /tmp/products.csv
FIELDS TERMINATED BY ,
ENCLOSED BY "
ESCAPED BY 
LINES TERMINATED BY 
FROM products

Two methods..
Use unique key
Run query such way-insert ignore into table.

A transactional database is defined for day-to-day operations like insert, delete and update and in a Datawarehouse databases (OLAP databases) are designed for Analytical purpose. So they require historical data for analysis. These databases are huge databases to store historical data.

1) Transaction database is designed for a specific application.Datawarehouse is designed to integrate data from multiple datasource.2) Transaction focuses on the details, Datawarehouse focuses on high...

If I am not wrong

Class variables are variables which we create inside a class.

&

Class member are the variables & function declared inside class.

In Two tier there will be Presentation layer and Data base layer
Where as in Three tire there will be Presentation layer,Data access layer and Data base layer

database is the collection of data in a well manner form

database is called when one computer are not connected with each other and only data are stored in one computer that called database and when computer are connected with each other or particular server so we can access the data every computer its called database server

Constraints divided into 3 types those are: 1. domain integrity constraints:- not null,check 2. entity integrity constraints:- unique,Primary key 3. referential integrity constraints:- foreign key In...

user-constraints and all_constraints

We can use "parallel" in the query and in the 11g we can use dynamic sampling.

Select query can be made faster by using indexes.

The number of entity type involved
i.e
One : Unary
Two : Binary
Three : Ternary

Degree of relationship is the cardinality of relationship that defines the number of instances of one entity as it relates to the number of instances of the other entity.Depending on the combinations ...

By using the concept of serial scanning the indexes can increase the searching capabilities.

An intersection table implements a many-to-many relationship between two business components.

A table added to the database to break down a many-to-many relationship to form two one-to-many relationships

The Relational model contains 3 components 1)set of relations and set of domains ( data structure).
2)Integrity rules (data integrity) and
3)The operation that can be operate on the data (data manipulation).

Relational model consists of three components:

1. A SET OF RULES for maintaining the INTEGRITY of the database.
2. MANIPULATIVE component consisting of a set of high-level operations which act upon and produce whole tables.
3. A Structural component -- a set of TABLES (also called RELATIONS).

Post block trigger belongs to Navigational triggers.

Navigation Trigger

Value set is a collection of values.A value set associated with a report parameters, provides a list of values to the end user to accept one of the values as report parameter value.

i thhink it is simmilar to enum in c/c++

Delete: delete a single row or multiple row it is DML operation so rollback is enable. Truncate: delete from all record in table. commit or rollback is not using. trigger will not fired.but column ...

In truncate all the data will be deleted whereas in delete also same but the difference in delete we again reback the data by using flashback (without use commit) in truncate it is not possible while drop the total table is drop

we use session to store the users information ,and can be use on next page when user click on next page. like we have a page for login which consist 2 text box one for username and another for passwo...

hi, when someone asked for test cases then test cases must be fulfill all the conditions, 1. Enter Valid User name and valid password And Click On Submit. 2. Enter Valid User name and valid passwor...

Expected result Actual result Launch the application Application should be launched Ente...