A primary key having two or more attributes is called composite key. It is a combination of two or more columns.An example can be −Here our composite key is OrderID and ProductID −{OrderID, ProductID}Let us see another example −StudentIDStudentEnrollNoStudentMarksStudentPercentageS001072172257090S002072179049080S003072176644086Above, our composite keys are StudentID and StudentEnrollNo. The table has two attributes as primary ... Read More

BigData and NoSQL are the choice for database solutions nowadays, but that does not mean the crucial features of RDBMS will die. Since 90% of the world data produced in last some years, therefore the need for RDBMS will not end in the near future.The RDBMS market is incrementing with ... Read More

Dependencies in DBMS is a relation between two or more attributes. It has the following types in DBMS −Functional DependencyFully-Functional DependencyTransitive DependencyMultivalued DependencyPartial DependencyLet us start with Functional Dependency −Functional DependencyIf the information stored in a table can uniquely determine another information in the same table, then it is called ... Read More

Tuples in Java are an ordered collection of objects of different types. To run Tuple in Java, you need to upload an external jar file. Here, we will be using Eclipse IDE to create a new Java Project and upload the JavaTuples external jar file.The JavaTuples jar file is to ... Read More

Disks are the mainly used mass storage devices. They provide the bulk of secondary storage in operating systems today.Disk StructureEach modern disk contains concentric tracks and each track is divided into multiple sectors. The disks are usually arranged as a one dimensional array of blocks, where blocks are the smallest ... Read More

An operating system is a construct that allows the user application programs to interact with the system hardware. Operating system by itself does not provide any function but it provides an atmosphere in which different applications and programs can do useful work.The operating system can be observed from the point ... Read More

A process is an active program i.e a program that is under execution. It contains the program code, program counter, process stack, registers etc.Process StatesThe different states that a process is in during its execution are explained using the following diagram −New- The process is in new state when it ... Read More

An operating system is a construct that allows the user application programs to interact with the system hardware. Operating system by itself does not provide any function but it provides an atmosphere in which different applications and programs can do useful work.The place of an operating system in a computer ... Read More

A relationship is an important part of any Entity relationship diagram as it shows the relation between two different entities. In an n - ary relationship, the n shows the number of entities in the relationship. It can be anything but the most popular relationships are unary, binary and ternary ... Read More

The different types of functions in Oracle are −Oracle String FunctionsOracle Numeric FunctionsOracle Date FunctionsMore details about these functions are given as follows −Oracle String FunctionsThe following are the Oracle String Functions −ASCII(str)This function returns the ASCII or numeric value of the first word in the string str provided. If ... Read More