Distributed Database Processing Lecture Notes

These flashcards cover key concepts in distributed database processing, including definitions of terms, techniques, and protocols essential for understanding the subject.

Distributed Database

A collection of multiple interconnected databases spread across various locations communicating via a computer network.

Replication

An approach in distributed databases where the entire relationship is stored redundantly at two or more sites.

Fragmentation

The process of dividing a table into smaller subsets called fragments, which are stored at different sites.

Horizontal Fragmentation

Dividing a relation into groups of tuples so that each tuple is assigned to at least one fragment.

Vertical Fragmentation

Dividing the schema of a relation into smaller schemas while ensuring each fragment retains a common candidate key.

Heterogeneous Distributed Database

A distributed database where different sites have different operating systems, DBMS products, and data models.

Homogeneous Distributed Database

A distributed database where all sites use identical DBMS and operating systems.

Two-Phase Commit Protocol

A distributed commit protocol that reduces vulnerability by ensuring all participant sites agree to commit or abort a transaction.

Global Directory

An extension of the normal directory that includes information about the location and makeup of fragments in a distributed DBMS.

Transaction Management

The control of transaction execution to ensure properties like atomicity, durability, serializability, and isolation in distributed databases.

Deadlock

A state in a database system where two or more transactions are waiting indefinitely for each other to release locks.

Concurrency Control

Techniques to ensure that multiple transactions can execute simultaneously without violating the consistency of the database.

Peer-to-Peer Architecture

A system where every peer acts both as a client and a server in providing database services.

Load Balancing

A technique used to distribute workloads across multiple computing resources to optimize resource use, maximize throughput, and minimize response time.

Query Optimization

The process of choosing the most efficient means of executing a given query by evaluating multiple execution plans.

Data Replication Techniques

Methods used to maintain copies of data across different sites to increase availability and ensure reliability.

Security Issues in Distributed Databases

Challenges associated with protecting data from unauthorized access and ensuring data integrity across multiple sites.

Client-Server Architecture

A model where client devices request resources or services from centralized servers.

Distributed Object Management

A method of managing objects that are distributed across multiple locations, providing a unified view to users.

Mobile Database

A database that can be accessed via mobile devices through wireless networks, allowing users to perform transactions remotely.

Semantic Data Control

Methods used to ensure semantic integrity and security of data in distributed databases.