Category Archives: Architecture

In Oracle Database, the distinction between instances and databases is essential for efficient data management. Let’s explore these concepts and compare the various startup and shutdown sequences.

In every Oracle Database environment, certain mandatory background processes are essential for the database’s operation and maintenance. These processes run by default in a read/write database instance that is started with a minimally configured initialization parameter file

Explore the essential steps involved in starting up an Oracle Real Application Clusters (RAC) environment. Understanding this sequence is crucial for database administrators and anyone working with high-availability databases. Let’s dive into the startup process.

The Program Global Area (PGA) is an essential memory structure in Oracle databases, specifically allocated for a dedicated server session. It is subdivided into various areas, each serving distinct purposes. Here’s an overview of the key contents of the PGA:

The Fixed SGA (System Global Area) is a predefined memory area within the Oracle database that serves essential housekeeping functions

The Streams pool is a dedicated memory area used exclusively by Oracle Streams to manage data replication and messaging

The Java pool is a dedicated area of memory within the Oracle database that stores session-specific Java code and data executed in the Java Virtual Machine (JVM).

The large pool is an optional memory area in Oracle databases designed for memory allocations that exceed the size limits of the shared pool.