Database Access from Application Programs

– To access the data from the database for further processing or to manipulate (insert/update/delete) data, queries are written in a language called the Structured Query Language (SQL) – Typically, the software for processing of the data and presentation to the users consists of application programs written in a host language, such as PL/SQL, Cobol,… Read More »

Instances and Schemas

As the data is modified by the users during the interaction with the database, the database (its structure and/ or the data) changes over time The collection of data stored in a database at a particular moment is called an instance of the data base The overall design of the database is called the database… Read More »

Data Abstraction

Most large enterprise databases today use huge data and complex data structures And, the applications built on top of these databases should present friendly and easily usable interfaces to the end users. Apart from end users, there are a number of stakeholders involved in building database applications including programmers, application administrators, database administrators etc. The… Read More »

Query Processor

The query processor helps the RDBMS to simplify and facilitate the access to the database The query processor handles the translation and updation of the queries As a result, a high-level view of the data can be provided to the developers so that they do not need to know physical level details to implement database… Read More »

Storage Manager in RDBMS

A “storage-manager” is a program module that provides the interface between the low-level data stored in the database and the application-programs and queries submitted to the system. The “storage-manager” is responsible for: Interaction with the file manager, by storing the raw data on to the disk using the file system For storing, retrieving, and updating data… Read More »

Overview of RDBMS

Objectives of RDBMS Discuss about the storage manager Describe what a query processor does Explain transaction management Explain the levels of data abstraction Explain how application programs access the database Describe the database system structure Discuss about database users and administrators Overview of RDBMS In the context of file systems vs DBMS, a question arises… Read More »