Q1. What is RDBMS?
Or
What is concept of RDBMS?
Or
What do you mean RDBMS?
Or
Explain RDBMS Database.
Ans. Stands for “Relational Database Management System.” An RDBMS is a DBMS designed specifically for relational databases. Therefore, RDBMS is a subset of DBMS.
A relational database refers to a database that stores data in a structured format, using rows and columns. This makes it easy to locate and access specific values within the database. It is “relational” because the values within each table are related to each other. Tables may also be related to other tables. The relational structure makes it possible to run queries across multiple tables at once.
While a relational database describes the type of database an RDMBS manages, the RDBMS refers to the database program itself. It is the software that executes queries on the data, including adding, updating, and searching for values. An RDBMS may also provide a visual representation of the data. For example, it may display data in a tables like a spreadsheet, allowing you to view and even edit individual values in the table. Some RDMBS programs allow you to create forms that can streamline entering, editing, and deleting data.
Most well known DBMS applications fall into the RDBMS category. Examples include Oracle Database, MySQL, Microsoft SQL Server, and IBM DB2. Some of these programs support non-relational databases, but they are primarily used for relational database management.
Examples of non-relational databases include Apache HBase, IBM Domino, and Oracle NoSQL Database. These type of databases are managed by other DMBS programs that support NoSQL, which do not fall into the RDBMS category.
Q.2 What is table?
Ans. Generally Table is a collection of similar objects where similar data are stored.
for example if you want to keep data of different books then you made a table for book and if you want to keep data of another type of object like: Pen then you make a table for a pen.
Tables are added in database as new type of object is need to keep track of.
Q.3 What is tuple?
Or
What is use of tuple in database?
Or
What do you mean by rows?
Ans. A table has rows and columns, where rows represents records and columns represent the attributes. Tuple − A single row of a table, which contains a single record for that relation is called a tuple. Relation instance − A finite set of tuples in the relational database system represents relation instance.
Q.4 What is field?
Or
What is column in database?
Or
Explain field element in database?
Ans. A database is a collection of tables. Each table has fields, or containers, to hold the data.
Q.5 What is a Relation Schema?
Ans. A relation schema describes the structure of the relation, with the name of the relation(name of table), its attributes and their names and type.
Q.6 What is a Relation Key?
Ans. A relation key is an attribute which can uniquely identify a particular tuple(row) in a relation(table).
Q.7 What is Java programming language?
Ans. Java is a general-purpose computer programming language that is concurrent, class-based, object-oriented, and specifically designed to have as few implementation dependencies as possible. It is intended to let application developers “write once, run anywhere” (WORA), meaning that compiled Java code can run on all platforms that support Java without the need for recompilation.
For example, you can
write and compile a Java program on UNIX and run it on Microsoft Windows,
Macintosh, or UNIX machine without any modifications to the source code. WORA is achieved by compiling a Java
program into an intermediate language called bytecode.
The format of bytecode is platform-independent. A virtual machine, called the Java Virtual Machine
(JVM), is used to run the bytecode on each platform.
Q.8 What is an operator in java language?
Or
What is use of operator in java language?
Ans. An operator is a symbol that performs a specific kind of operation on one, two, or three operands, and produces a result. The type of the operator and its operands determines the kind of operation performed on the operands and the type of the result produced.
Q.9 What is array in java language?
Ans. An array is
a container object that holds a fixed number of values of a single type. The
length of an array is established when the array is created. After creation,
its length is fixed. You have seen an example of arrays already, in the main method of the “Hello
World!” application. This section discusses arrays in greater detail.
Q.10 What do you understand Wrapper classes in java?
Ans. Java provides type wrappers, which are classes that encapsulate a primitive type within an object. In Java, we have 8 primitive data types.
A wrapper class wraps (encloses) around a data type and gives it an object appearance. Wherever, the data type is required as an object, this object can be used. Wrapper classes include methods to unwrap the object and give back the data type.
The type wrappers classes are part of java.lang package.
Each primitive type has a corresponding wrapper class.
| Primtive Type | Wrapper Class |
| double | Double |
| float | Float |
| long | Long |
| int | Integer |
| short | Short |
| byte | Byte |
| char | Character |
| boolean | Boolean |
