Oracle Database Server Basic Structure for Starters

Explanation of Oracle Database Server - For Starters

How Oracle Database Server Works?

The Oracle Database Server majorly consists of two parts i.e.

1. Instance

2. Database

These two components combine to create an Oracle Database Server. Or simply you can say that

Oracle Server = Instance + Database

Oracle Database Instance

Most of the times people get confused about this instance thing. I'll make it very easier for you to clarify the concept of instance.

Instance = Memory(RAM) + Some Background Processes

So what we conclude from the above equation is that instance is nothing but some part of RAM (Random Access Memory) and some running background processes in oracle. As simple as it is. There is nothing to get confused.

When you start your database, a particular portion of your RAM is allocated to the Oracle Database and some background processes start working. At this moment, we can say that the instance has initialized.

There's a lot more to know about instance, SGA (Shared Global Area) & PGA (Program/Process Global Area) which I'll be writing in my upcoming articles.

Database (Physical Files)

A database is normally a collection of data, which is mainly stored in tables, in the form of rows and columns. The Columns contains the attributes and the rows contains the assigned values as per the attributes. 

It doesn't matter what type of the data is, it'll always be stored in the form of tables when we talk about a database.