What is Database Writer (DBWR) and when does DBWR write to the data file?

@ : Home > > Interview Room

DBWR is a background process that writes data blocks information from Database buffer cache to datafiles.

There are seven important situations when DBWR writes to data file:

  1. Every 3 seconds.
  2. Whenever a checkpoint occurs.
  3. When server process needs free space in database buffer cache to read new blocks.
  4. Whenever some blocks reaches a maximum value.
  5. Timeout occurs.
  6. RAC ping request is made.
  7. When any tablespace is taken offline, read only, drop or truncated & when to begin the backup.
Alert me