Suresh

• Jul 19th, 2005

 

A instance is basically a set of memory and some background processes.

cmanne

 Profile Answers by cmanne 

• Jan 4th, 2006

 

An Oracle instance is a combination of background processes and memory structures (SGA)

imran44

 Profile Answers by imran44 

• Jul 10th, 2009

 

SGA+Background Process = Instance

As soon as user process starts and server process takes control from user process, instance created with help of background processes and most important background processes are dbwriter, logwriter, checkpoint, SMON, PMON and components of SGA are shared pool, database buffer cache, redo log cache, large pool, stream pool.

Most important library cache + Data Dictionary=Shared Pool