Category: Know This First

Optimized Query Execution Plan

Optimized query execution plan is the execution plan prepared by DBMS for a user query. Its steps might differ from the steps in user query, but it will deliver the same result efficiently. In...

Graph Traversal Algorithms For DBMS

When understanding the Database concepts, we will often encounter optimization problems related to database performance. Let’s understand one Graph Traversal Algorithms For DBMS and its solution. Travelling salesman problem: The Travelling Salesman Problem describes a...

Cache

The default caching mechanism of operating system may not meet the caching needs of a database system. Because Database may not store data inform of files that the operating system understands. The data may...

Selectivity

Predicate: A predicate is a filtering conditions that selects a certain number of values from a value set. Example of a predicate may be : “age = 25” or “country = India”. Selectivity represents...

Semantic Equivalence

In a spoken language it is possible to create different statements, that have the same meaning. This is called semantic equivalence of statements. Similarly, in your query language, it may be possible to specify...

Bison Grammar

When you create your own database, you also have to define a query language. A query language can be as confusing as a real world language if the syntax rules are not well defined. A...