3-3 CKPT (Checkpoint processes)

What is CKPT?

A database event synchronizes modified data blocks between [Buffer Cache and Control files + Data files] in memory

2 Purposes

1. Data consistency between [memory and disk]

2. Faster database recovery process

Control Files

• Small binary file that records the physical structure of database

• Keeps track of the location (name or path of certain files in the Oracle storage)

• Not the names of tables or columns. They are logical structure

• Every Oracle database has a control file

CKPT Process

Put SCN (system change number) as unique identifier on

• The headers of Data Files

• The control files

CKPT doesn’t write the actual data blocks from memory to disk - it’s DBWn’s job