Oracle Architecture
Databases and Instances
Oracle Database Structures
Shemas
Tablespaces
Files of a database
Pluggable Databases
Databases Initialization
Deploying Physical Components
Control Files
Datafiles
Datafile Structure
Extents and segments
Redo Logfiles
Multiplexing redo logfiles
How Oracle uses the redo logs
Naming conventions for redo logs
Archived redo logs
ARCHIVELOG mode and automatic archiving
Instance Memory and Processes
Memory Structures for an Instance
Database buffer cache
Shared pool
Redo log buffer
Automatic PGA management
The Data Dictionary
Instance : Software running the service that provides access to the database.
Database: Physical storage of information
Logic isolation unit
Control of data structures within it
Logical structure that allows to have a space to store the database elements.
Control files
Datafiles
Redo logfiles
Safeguards vital object information
Is an isolation layer between a database instance and a schema.
Operations and entities are implemented in the CDB and operate in separate PDBs
When the database is initialized the initialization parameters are read
A database must have two copies of the control file on different physical disks to safeguard the data.
Contain actual data stored in the database
The first block of a data file is data file header
Control point
Maintains the integrity
Timestamp indicating which was the last change made
Extension: sequence of data blocks within an oracle data file
Segment: object occupying a space in the database
Contain recordings of changes made in the database as a result of transactions
Oracle uses a subprocess redo logs to record database changes.
When a redo log file is filled, the following log file starts to be used
Clear identification of files by name
An instance can be defined as shared memory and background processes
cache memory that contains blocks of data where they can be consulted quickly without having to go to the disk.
Caches data that can be shared among users
Stores redo log information until rebuild log files are written to disk
Manages the memory allocated to an instance
Tables and views containing metadata