Database System Architecture Overview - SGA, PGA, and File Structures Explained #3729023 (License: Personal Use)

This diagram outlines the internal structure of a database instance, highlighting the System Global Area (SGA) with its caches (Library, Data Dictionary, Database Buffer, Redo Buffer), the Program Global Area (PGA), background processes (DBWR, LGWR, CKPT, SMON, PMON), and associated files (data, control, online redo, archived redo). It also shows user and server processes interacting with the instance and memory structures like the shared pool and large pool.

This image is typically used in database administration, DBMS coursework, or technical documentation to explain how Oracle-like database systems organize memory, processes, and persistent storage. It serves users seeking foundational knowledge of database internals for study, certification, or system tuning.