Database System

Heuristic in Query optimization

Heuristic optimization often includes making transformations to the query tree by moving operators up and down the tree so that

Before query optimization is carried out, one would of course need to decide what needs to be optimized. The goal

In most database systems, queries are posed in a non-procedural language like SQL and as we have noted earlier such

SQL language also includes syntax to update, insert, and delete records. These query and update commands together form the Data

The Data Definition Language (DDL) part of SQL permits database tables to be created or deleted. We can also define

There are three groups of commands in SQL: 1. Data Definition 2. Data Manipulation and 3. Transaction Control

Structured Query Language, commonly abbreviated to SQL and pronounced as “sequel”, is not a conventional computer programming language in the

Once entities and relationships have been identified and defined, the first draft of the entity relationship diagram can be created.

Several criteria are normally used to classify DBMSs. The first is the data model on which the DBMS is based.