In previous story, we have covered creating CDB and PDBs.

1. Part 1 — Install Oracle Database 19.3c on CentOS 7 -: https://kalanaejayasuriya.medium.com/install-oracle-database-19-3c-on-centos-7-52036876436
2. Part 2 — Oracle Database 19.3c — Multitenant Architecture, Create CDB and PDB -: https://kalanaejayasuriya.medium.com/oracle-database-multitenant-architecture-create-cdb-and-pdb-4a9bb954803b

In this part I am going to talk about listener and how we register PDB with a listener. Before we begin let us talk about listener.

What is listener in oracle?

If we simply explain, Listener is the middleware between user and the servers.

If we discuss in advance, Listener is a server-side process that can listen to incoming requests from client side and manage traffic to the…

In previous story, we covered how to install oracle 19.3c on CentOS 7 (https://kalanaejayasuriya.medium.com/install-oracle-database-19-3c-on-centos-7-52036876436). In this part we will cover installation of CDB and PDB. Before began installation, lets talk about what is CDB and PDB.

Multitenant Architecture

• After Oracle 12c, Oracle came up with new architecture called “Multitenant Architecture.”
• In previous versions of Oracle database versions main problem was, if user start new instance there are particular background processes for each instance. This process is kind of memory wasting thing and affect to the system performance badly.
• Therefore, Oracle came up with the new idea to connect different databases into one…

What is Oracle Database?

Oracle Database is a multi-model database management system. It means a database that can store, index, and query data in more than one model. Also, it is a free product that can use by everyone.

What are the uses of Oracle Database?

Most commonly, it uses Data Warehousing (DW), Online Transaction Processing (OLTP), and both mix of DW and OLTP.

Evaluation of Oracle Database

Oracle started its first product as “Oracle v2” and then upgraded it until “Oracle 7.3” as regular versions.

After that, they evaluate their oracle versions using three categories that started in 1998.

• The “i” version -: Stands for “internet.” Ex: Oracle 8i, Oracle 9i
• The “g” version…

Many peoples have lot of problems with C format specifiers. Most of them don’t know how to use it, when can use it, ranges of data types and etc. I have studied these format specifiers and it takes few hours to complete this article.

I would like to show these using table and give an example to each format specifier by explain them.

char

Format  Description  Type              range         Uses
 %c     Character    char           -128 to 128   Use to output 
                                                  single character %c     Character    unsigned char     0 to 255   Use to output  
                                                  single character %s String char [] — Use to output…

Introduction

Nowadays, information retrieval systems are viral and very useful to peoples seeking answers to their problems and managing their time. Medical information retrieval systems are one of the critical systems out of other retrieval systems. Those are very important for doctors, patients, and all who are related to the medical side. If someone searches for medical information in WWW (World Wide Web), they can get more than a thousand results related and non-related to your topic there for you will find it challenging to get the most helpful answer to your question. If someone can access a system that is…