Architecture and Administration Q012

What is a dirty buffer?



1. A data buffer that is being accessed.
2. A data buffer that is changed but is not yet written to the disk.
3. A data buffer that is now free.
4. A data buffer that has changed and has been written to the disk.



Answer 2 - Dirty buffers are the buffer blocks that need to be written to the data files. The dat in these files is changed and is not yet written to the disk. A block waiting to be written to the disk is on the dirty list and cannot be overwritten.