Sakar Pradhananga

Differentiate between homogeneous and heterogeneous distributed database management system with example. What do you mean by (A1, D2, H1) and (A0, D1, H0) architecture?

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A Distributed Database Management System (DDBMS) allows data to be stored and accessed across multiple sites, but these systems can be categorized as either homogeneous or heterogeneous, depending on how the databases at different sites are structured and managed. 1. Homogeneous DDBMS: 2. Heterogeneous DDBMS: (A1, D2, H1) and (A0, D1, H0) Architecture: These notations … Read more

What is meant by Distributed Databases? Why should one opt for Distributed Database Implementation instead of Centralized approach? Discuss.

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A Distributed Database is a type of database that is spread across multiple physical locations, which may include different computers or servers. These locations are connected through a network, and the database operates as if it were a single database system, even though it is distributed across different sites. In a distributed database, the data … Read more

Discuss the difference between Parallel DBMS and Distributed DBMS.

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A Parallel Database Management System (Parallel DBMS) and a Distributed Database Management System (Distributed DBMS) both aim to improve performance, scalability, and reliability, but they differ significantly in their architecture, data management strategies, and use cases. Parallel DBMS: A Parallel DBMS is a system where multiple processors or computers work together within a single database … Read more

With the help of a figure, discuss the function of Local Recovery Manager.

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The Local Recovery Manager (LRM) is a crucial part of a database management system, responsible for ensuring data consistency and integrity in case of system failures. These failures may include scenarios such as system crashes, hardware malfunctions, power outages, or application failures. The LRM coordinates the entire process of restoring the database to a consistent … Read more

Timestamp-Based Protocols

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Timestamp-based protocols are used in databases to control how transactions are executed when multiple transactions are running at the same time. These protocols help ensure that transactions don’t conflict with each other, causing issues like reading incorrect data or overwriting changes made by another transaction. Instead of using locks, like in lock-based protocols, timestamp-based protocols … Read more

Lock-Based Protocols

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Lock-based protocols are a method of concurrency control in database management systems (DBMS). They ensure that multiple transactions can access the database simultaneously without violating data integrity and consistency. These protocols allow transactions to lock data items to avoid conflicts like reading inconsistent data or overwriting changes made by other transactions. In simpler terms, a … Read more

Explain the concept of serializability and its types.

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Serializability – Concept and Explanation Serializability is a key concept in database management, particularly in the context of transaction processing. It refers to the property of a schedule (a sequence of operations or transactions) that ensures the database maintains consistency and correctness, even when multiple transactions are executed concurrently. In simple terms, serializability ensures that … Read more

Explain Query optimization and its main components.

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Query optimization is the process of improving the performance of a database query by minimizing the resources (such as CPU time, memory usage, and I/O operations) required to execute the query. It involves transforming the given query into an equivalent one that can be executed more efficiently. In relational databases, query optimization is essential because … Read more

System R

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System R is one of the first prototypes of a relational database management system (RDBMS), developed at IBM in the 1970s. It was an experimental project aimed at proving the feasibility and practicality of the relational model of data, which was proposed by E.F. Codd. System R laid the foundation for modern relational database systems … Read more

INGRES Algorithm

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The INGRES (Interactive Graphics and Retrieval System) algorithm is a well-known database query processing algorithm developed as part of the INGRES (Interactive Graphics and Retrieval System) project. It was designed to handle relational database management system (RDBMS) queries, focusing on efficient query processing and optimization. The INGRES algorithm is mainly associated with query optimization, specifically … Read more