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Database Management System

Describe the data structures implemented by the storage manager.

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Data Structures Implemented by the Storage Manager: The storage manager implements several data structures as part of the physical system implementation. Data Files: It stores the database itself. Data Dictionary: It stores metadata about the structures of the database, in particular schema of the database. Indices: It can provide fast access to data items. It … Read more

What is storage manager? Describe the components of storage manager. DBMS

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What is storage manager? Describe the components of storage manager. DBMS

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, and the physical storage media, typically disk drives.

At its core, the Storage Manager is responsible for efficiently organizing and managing the persistent storage of data. It provides an interface between the logical representation of data within the DBMS and the physical storage devices where the data resides. This involves translating high-level data operations and requests from the DBMS into low-level disk operations, ensuring that data is stored, retrieved, and managed reliably.

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In how many ways can database constraints be tested/evaluated? Describe briefly. DBMS

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Database Constraints: Database constraints are like conditions given to the manipulation of values of a field or attribute. Such as, we may limit the values under the payment attribute of a table that its value can never be less than BDT 350. Constraints can be tested as follows, Domain Constraints: Using domain constraints one can … Read more

Describe Data Definition Language (DDL). DBMS

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Data Definition Language (DDL): The specific language used to express the database schema by a set definitions is called Data Definition Language (DDL). The DDL is also used to specify additional properties of the data. Another special type of DDL, called the Data Storage and Definition Language, is used to specify storage and data access … Read more

What are database languages? Describe DML (DBMS)

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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 … Read more

What is data model? Describe various data models. DBMS

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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 … Read more

What are instances and schema? DBMS

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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 … Read more

What is data abstraction? Describe the levels briefly. DBMS

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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 … Read more

Briefly describe the disadvantages of file processing system? DBMS

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Disadvantages of File Processing System: Keeping organization information in a file processing system has some disadvantages including the followings, Data Redundancy & Inconsistency: As the files are created by different programmers, there is a huge chance of data redundancy which is responsible for unnecessary storage and access cost. This may also lead to data inconsistency … Read more

What are the applications of DBMS?

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Applications of DBMS: DBMS is getting used in many places. Everything from file cabinets to dictionaries is disappearing from today’s working place, because it is easy to make use of the data using a DBMS. The uses or applications of DBMS include the following, In Banking: For customer information, accounts, loans and banking transactions. This … Read more