Deadlock in DBMS

Deadlock in DBMS A deadlock is an unwanted condition in which two or more transaction are waiting indefinitely for one another to give up locks. It is said to be one of the most feared complications in database management system …

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Concurrency Control Protocols

Concurrency Control Protocols Concurrency control protocols ensure the atomicity, serializability and isolation of the concurrent transactions. The Concurrency control protocols can be broadly classified into the following categories: Lock Based Protocol Timestamp protocol Lock Based Protocol In this protocol, any …

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Serializability in DBMS

Serializability in DBMS Serializability is the concept in a transaction that helps to identify which non-serial schedule is correct and will maintain the database consistency. It relates to the isolation property of transaction in the database. Serializability is the concurrency …

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DBMS Schedule

A schedule is a process of combining the multiple transactions into one and executing the operations of these transactions in a predefined order. A schedule can have multiple transactions in it, each transaction comprising of several tasks or operations or …

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What is a Transaction?

A transaction is a collection of logically related operations which reads and possibly updates the various data items in the database. Usually, a transaction is initiated by a user program written in high-level DML language (SQL), or programming language, with …

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What is Normalization?

Normalization is a technique of organizing the data in the database. It is a systematic approach which is used to remove or reduce data redundancy in the tables and remove the insert, update, and delete anomalies. It mainly divides the …

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Inference Rules

Armstrong’s axioms are the complete set of basic inference rules used to infer all the functional dependencies on the relational database. An inference rule is a type of assertion that a user can apply to a set of functional dependencies …

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Multivalued Dependency

Multivalued Dependency exists in a relation when two attributes depend on the third attribute but independent to each other. It is a full constraint between two sets of attributes in a relation. It plays a vital role in 4NF. Multivalued …

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Functional Dependencies

Functional Dependencies (FD) in the relational database management system occurs when one attribute in a relation uniquely determines other attribute in that relation. It describes the relation between the attributes. The term functional dependency was introduced by E.F Codd. It …

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DBMS Joins

Joins are the combination of related tuples from the two different relations or tables into a single type. It is similar to the Cartesian product except the fact that in Cartesian product operation, a user gets all the possible combinations …

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Relational Algebra

Relational Algebra is a widely used procedural query language, which takes instances of one or more relation as an input and generates a new relation as an output. It uses a different set of operators (like unary or binary operators) …

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DBMS Keys

In database management system, keys play an important role which is used for identifying unique records by the combination of one or more fields in the database table. Keys also allows you to establish the relationship between the database tables. …

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