Indexing is a technique for improving database efficiency by reducing the number of disk accesses necessary while a query is completed. It is a data structure strategy for fast locating and accessing data in a database. A few database columns are useful to generate indexes. The first column is the Search key, which contains a … Read more
Concurrency Control is concerned with the interleaved execution of several transactions. In the following article, we will define transaction and schedules in Concurrency Control. Transaction in Concurrency Control A set of logically related operations is basically the transaction. The main operations of a transaction are , read, write, commit and rollback.Basic properties of a transaction … Read more
In this tutorial we are going to learn about normalization in DBMS. Data duplication may occur in a big database defined as a single relation. This data repetition may result in:Increasing the size of relationships.It is difficult to manage and update data because it requires searching through several records in relation.Wastage and inefficient use of … Read more
Functional dependencies are relationship between two qualities. Within a table, it is often found between the primary key and a non-key property.X -> Y. The left side of FD is a determinant, while the right side of the production is the dependent. Types of Functional Dependencie Trivial functional dependencies If B is a subset of … Read more
E.F. Codd proposed the Relational Model to model data in the form of relations or tables. After creating the database conceptual model using an ER diagram, we must transform it to a relational model. We can implement using any RDBMS language ,for example, Oracle SQL or MySQL. What is a Relational Model and how does … Read more
Generalization, Specialization and Aggregation, are data abstraction mechanisms in the ER model. They are useful to hide specifics of a set of objects. Generalization in ER Model This is similar to a bottom-up method. Here, generally two or more lower-level entities unite to generate a higher-level object. But they must share some features. In principle, … Read more
Entity Relationship model (ER model) is a high-level data model. This model is useful to specify the data items and relationships for a specific system. It creates the conceptual architecture of a database. It also generates a data view that is relatively simple to construct. In ER modeling, the database structure is represented by an … Read more
In this tutorial, we will learn about data models in DBMS. A data model is a set of tools to summarize the database‘s description. The modeling of the data description, data semantics, and data consistency constraints is basically a data model. It gives you the conceptual tools you need to describe a database’s design at … Read more
In this tutorial, we are going to learn about types of databases in use, small introduction of them, their properties and examples. Centralized Database It is a centralized database system that stores information in a database. It enables users to access data stored in the system from a variety of locations and through a range … Read more
In this tutorial, we will learn about DBMS architecture. Users and programs may not always be able to directly access and store data in a Database Management system. Depending on its architecture, a Database Management system can be centralized (all data is stored in one area), decentralized (many copies of the database are maintained in … Read more
In this tutorial, we are going to learn about Database Management System. Data is a collection of one-of-a-kind small bits of information. Text, numbers, media, bytes, and other types of data can all be useful to create it. We can, for example, save on paper or in an electronic memory. A database basically is a … Read more