PL/SQL – An Overview

  • An extension to SQL with design features of programming languages  (procedural and object oriented)
  • PL/SQL and Java are both supported as internal host languages within Oracle products.
  • The PL/SQL procedural language was developed by Oracle Corporation in the late 1980s as procedural extension language for SQL and the Oracle relational database.

Following are notable facts about PL/SQL:

  • It is a completely portable, high-performance transaction-processing language.
  • PL/SQL provides a built-in interpreted and OS independent programming environment.

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Structured Query Language – SQL – Basics

SQL, a Structured Query Language is now available with most RDBMS (Relational Database Management System) products as the database language. Which can be used both by end-users and system programmers.

Originally, SQL was called SEQUEL( for Structured English QUEry Language).

SQL is now standard language for commercial relational DBMS.

First reason, a query in relational algebra is written as a sequence of operations that, after execution, produce the required result. Hence, the user must specify how –that is, in what order – to execute the query operations.

On the other hand, the SQL provides a high-level declarative language interface, so the user only specifies what the result is to be, leaving the actual optimization and decision on how to execute the query to the DBMS.

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In our previous lecture we discussed

Most of all basics of the Relational databases

Objectives of Normalization

Modification anomalies includes Deletion Anomaly and Insertion Anomaly also Updation Anomaly

Functional Dependencies and  Fully Functional Dependencies with Armstrong’s axioms of FD etc.

Now we have to talk about Normalization and  Different forms of normalization.

Continue reading “Normalization-II”