Database Administrator: One of the main reasons behind using DBMS is to have central control on both data and the applications access those data. The person who has such central control over the data is called a database administrator (DBA). Some of the functions of DBA are given below, Schema Definition: The DBA creates the …
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Transaction: A transaction is a collection of operations that performs a single logical function in a database application. Such as, when we want to add BDT 500 to account A and subtract BDT 500 from account B, that will be a transaction. Transaction Management: Transaction is a unit of both atomicity and consistency. Thus it …
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Storage Manager in a Database Management System in DBMS The Storage Manager is a crucial component of a Database Management System (DBMS) that handles the storage, retrieval, and management of data on secondary storage devices. It acts as a bridge between the higher-level components of the DBMS, such as the query processor and transaction manager, …
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Database Language: As whatever we want to be manipulated by computer has to be written using specific language, database is not beyond them. To write or create database management system we use database languages. They are of two types; Data Definition Language (DDL) and Data Manipulation Language (DML). DDL is used to design a database …
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Data Model: Data model is the structure of the database, which is a collection of conceptual tools for describing data, data relationships, data semantics and consistency constraints. The data models can be classified into the following four categories. Relational Model: The relational data model uses a collection of tables to represent both data and the …
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Instances: A database is generally used by many users where insertion and deletion of data occurs frequently. Overall information stored in a database at a particular moment is called the instance of the database. Schemas: The overall design of a database which includes the data structures, table designing and relation of data from table to …
Data Abstraction: Different users require different view of the database which is useful and necessary to them. This is data abstraction by which we abstract useful data from a database for a particular type of users to use. There are 3 levels of data abstraction, those are as follows; Physical Level: The lowest level of …
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Database: A database contains a collection of related items or facts arranged in a specific structure. The most obvious example of a non-computerized database is a telephone directory. DBMS (Database Management System): A database management system is a collection of interrelated data and a set of programs to access those data. It allows people to …
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Wavelet: Wavelets are tiny parts of waves. Secondary wavefront: The envelop of all the secondary wavelets in the forward direction is called the secondary wavefront. The backward envelop is not a secondary wavefront.
Wavefront A wavefront can be defined as the locus of all the points of the medium which are vibrating in phase and are also displaced at the same time. If the distance of the source is small the wavefront is spherical. But when the distance is large then any small portion of the wavefront can …
