RDBMS

Structured data type

A structured data type is a user-defined data type with elements that are not atomic; rather, they are divisible and can be used either separately or as a single unit, as appropriate. A structured data type is a form of user-defined data type that contains a sequence of attributes, each of which has a data type. An attribute is a property that helps describe an instance of the type.

SQL

Structured Query Language. The most popular relational database query language.

ODBMS

(Object Oriented Database Management System) A database management system that employs Object-Oriented concepts to data management.

Data model

A collection of concepts that describes the structure of a database such as tables etc.

Record

A collection of fields relating to a specific entity.

Data

A collection of measurable facts and figures about a subject of interest.

Query

A command issued to a DBMS to carry out some intended action.

Database management system

A computerized system that manages and controls an electronic database.

Deadlock

A condition in concurrent transaction processing in which some of the participating transactions cease to execute.

Relational data model

A data model based on rigorous theoretical considerations in which data is represented in a simple table like row-column format.

"Network model

A data model consisting of a collection of records of data connected to one another through links.

Entity-Relationship model

A data modeling tool that treats each object of the miniworld as a separate unit having individual attributes and being related to one another.

Redundancy

A database condition when the same data values are stored in multiple copies.

Distributed database

A distributed database is a database which is under the control of a central database management system (DBMS) in which storage devices are not all attached to a common CPU. It may be stored in multiple computers located in the same physical location, or may be dispersed over a network of interconnected computers.

Information

A fact derived as processed data.

Audit file

A file that is used to record usage of resources.

Backup file

A file that stores a copy of the original files so that the data may be recovered in case any disruption occurs.

Data Definition Language (DDL)

A language specifying procedures through which users can describe the data, their types, their structures and constraints for the data to be stored in the database.

Data Manipulation Language (DML)

A language used to describe operations on a database.

Application Program Interface (API)

A library of functions and procedures that can be called in.

Binary locks

A lock having only two values.

Two-phase locking

A locking protocol in which all locking operations precede the first unlock operation.

Super key

A non-empty set of attributes of a relation such that no two tuples in any valid relation instance have the same value.

Attribute

A property of an entity whose data is to be stored.

Table

A relational data models object comprising rows and columns of data.

RDBMS

A relational database is composed of many relations in the form of two dimensional tables of rows and columns containing related tuples.

Database

A repository for all the files of an organization structured and integrated to facilitate updation of files and retrieval of information from them.

Database

A repository of well-organized data.

Tuple

A row in the table having values for each column.

Bit

A short for bi(nary digi)t. It can assume either of the two values, representing numeric value 0 or 1.

Trigger

A stored procedure that gets executed even without explicit invocation by the user when the database enters into some specified state or a specified event takes place. Embedded query language: A query languages wherein a programmer can embed database query statement in a program written in another programming language.

Data fragmentation

A system supports data fragmentation if data or file can be divided into pieces (fragments) for physical storage purpose.

Normalization

A systematic method of obtaining good database design based on the functional dependencies of a relation schema.

Metadata

Additional data about a given set of data.

Key Attribute

An attribute of an entity that uniquely determines each instance of an entity.

Weak entity

An entity type that does not have a key attribute of its own.

Objects

An object is defined by the attributes that describe the real-world entity that it is modelling.

Pessimistic concurrency control

Concurrency control technique that assumes that there will definitely arise conflict between the transactions and therefore take steps to avoid it.

Quantitative data

Data capable of being expressed in numerical terms.

Encapsulation

Data encapsulation or simply encapsulation allows the hiding of the internal state of the objects.

Qualitative data

Data which can only be expressed using codes (numeric or otherwise) and can be arranged in some agreeable ranked order.

Discretionary access control

Discretionary access control (DAC) is an access policy determined by the owner of an object. The owner decides who is allowed to access the object and what privileges they have.

Byte

In computer system, a basic unit of information generally stored by using 8 bits in a specified combination.

Serializability

In databases, schedule has the Serializability property, if its outcome (the resulting database state, the values of the database's data) is equal to the outcome of its transactions executed sequentially without overlapping.

Inheritance

Inheritance allows one to develop solutions to complex problems incrementally by defining new objects in terms of previously defined objects.

Polyinstantiation

It allows a relation to contain multiple rows with the same primary key; the multiple instances are distinguished by their security levels. Polyinstantiation is the ability of a database to maintain multiple records with the same key. It is used to prevent inference attacks.

Concurrency control

It ensures that database transactions are performed concurrently without the concurrency violating the data integrity of a database.

Multi version concurrency control (MVCC)

It is a concurrency control method commonly used by database management systems to provide concurrent access to the database.

Query optimization

It is a function of many relational database management systems in which multiple query plans for satisfying a query are examined and a good query plan is identified.

Multiple granularity locking (MGL)

It is a locking method used in database management systems (DBMS) and relational databases. In MGL, locks are set on objects that contain other objects. MGL exploits the hierarchical nature of the contains relationship.

Data Replication transparency

It means that basic idea is that a given logical object, say a given account record, may be represented at physical level by many distinct copies.

Recoverability

It means that committed transactions have not read data written by aborted transactions (whose effects do not exist in the resulting database states).

Mandatory Access control

Mandatory access control (MAC) is an access policy determined by the system, not the owner. MAC is used in multilevel systems that process highly sensitive data, such as classified government and military information.

Encryption

Network encryption can ensure that data moving to and from a data warehouse over a network is hidden from unauthorized users. Encryption of stored data fields protects very sensitive data that might otherwise be viewed.

Object oriented database management system

Object-Oriented Database Management Systems, commonly known as OODBMS, provides consistent, data independent, secure, controlled and extensible data management services to support the object-oriented model. They were created to handle big and complex data that relational databases could not.

Polymorphism

Polymorphism allows the same operator or symbol to have different implementations, depending on the type of objects to which the operator is applied.

Serializability

Property of transaction schedule in which participating transactions can be executed in a serial manner.

Roles

Roles address the complexity of privilege management by providing user-defined collections of privileges that can be granted to (and revoked from) users and from other roles.

Database administrator

The database user who is responsible for making decisions and controlling the database.

Parallel database systems

These systems attempt to exploit recent multiprocessor computer architectures in order to build high-performance and high-availability database servers at a much lower price than equivalent mainframe computers.