1. Shutdown Immediate
1. Shutdown Abort
The database is forcibly shuts down and may not be consistent and requires recovery during startup. SMON ensures that the database is consistent (REDO/ UNDO)
All the users who are working on the system gets terminated abruptly and the intermediate data is lost. (Which is committed)
2. Shutdown Immediate
The database is shutdown immediately but all the committed transaction are updated in the database and opened transactions are rolled back. No new connections are allowed.
3. Shutdown Transactional.
The database does not allow any new connections, all the committed data is updated
In the database and opened transactions are only allowed to complete, no new transactions are allowed.
4. Shutdown Normal
It allows the users to complete all the transactions and shut down the database. No new connections are allowed but time consuming to stop the database.
The database uses file system but organized in the RDBMS concept. The data is stored in terms of Database block size in terms of Datablocks. Each block size is 8KB(8192 Bytes)
Block size is determined by parameter DB_BLOCK_SIZE (refer inti<sid>.ora)
The two parameters DB_NAME and DB_BLOCK_SIZE should never be modified.
Data files are physical files on the file system where data is stored in Datablocks.
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