Memory Architecture

• System Global Area : Shared memory segment which is allocated at instance creation time. It is accessible to all Oracle processes and generally very large (several 100MB or GB). It contains :

• DB buffer cache :

• - it holds thousands of DB buffers (each

• holding one DB block). Each block is of

• size DB_BLOCK_SIZE. It can’t be changed

• without recreating the DB.

• - server process retrieve data from disk into

• buffers, changes are made here and DBWR

• writes them out to disk.

Previous slide

Next slide

Back to first slide

View graphic version