Skip to main content

Oracle Memory Structure - Oracle Architecture

SGA - System Global Area

SGA is a  group of shared memory area which is dedicated to oracle instance.

Shared Pool

Shared pool is dividing into two major areas which are :

  • Library Cache : Area which stores the SQL information such as select statements, cursors and execution plans.
  • Data Dictionary Cache : Which contains cache, user information and privileges, segments and extent information as well.
Buffer Cache


Buffer cache holds blocks of data from disk that have been recently read to satisfy a select statement or that contains modified data-blocks. 

Redo Log Buffer

Redo Log buffer holds the most recent changes to the data blocks in the data-files.  

Large Pool

This is an operational area of the SGA it is used for transactions that interact with more than one database.

Java Pool

Java Pool is used by the Oracle JVM (Java Virtual Machine) for all Java code & data within user session.

Stream Pool

Stream Pool is sized by using the initialization parameter STREAMS_POOL_SIZE. the stream pool holds data & control structures to support Oracle stream feature of Oracle Enterprise Edition. 

PGA - Program Global Area


PGA is an area of memory allocated and private for one process.



Comments

Popular posts from this blog

Behavior Driven Development

Behavior Driven Development (BDD) is a development process that originally associated with Test-Driven Development (TDD).  BDD is written in a readable format in an understandable language for anyone involved in software development.  BDD Features Providing better readability and visibility.  Verifying the software against customer requirements.  Assure the implementation of the system is correct. Derives examples of different expected behaviors of the system. Uses examples as acceptance tests. Focus on customer requirements throughout the development. BDD Practice There are two practices in BDD:-  Specification by Example (SbE). Test-Driven Development (TDD). Specification by example (SbE) uses examples in conversation to illustrate the business rules and the behavior of the software.  This uses to have a better understanding for Business Analyst, Product Owners, Testers and the Developers to reduce the misunderstanding abou...