Types of Checkpoints in Oracle.

Checkpoint types can be divided as INCREMENTAL and COMPLETE.

Also COMPLETE CHECKPOINT can be divided further into
PARTIAL and FULL.

In Incremental Checkpoint,checkpoint information is written to the
datafile header and controlfile In the following cases:

1.Every three second.
2.At the time of log switch.

In complete Checkpoint,checkpoint information is written
in controlfile,datafile header and also dirty block is 
written by DBWR to the datafiles.

Full Checkpoint
1.fast_start_mttr_target 
2.Before Clean Shutdown

partial Checkpoint happens in the following cases.

1.before begin backup.
2.before tablespace offline.
3.before placing tablespace in read only.
4.Before dropping tablespace.
5.before taking datafile offline.
6.When checpoint queue exceeds its threshold.
7.before segment is dropped.
8.Before adding and removing columns from table.