The online patching cycle in R12.2 which uses ADOP utility applies patch in 5 Phases
The phases are
PREPARE
APPLY
FINALIZE
CUTOVER
CLEANUP
PREPARE PHASE:
1)Prepares the Filesystem
During Prepare phase,RUN and PATCH filesystems are synchronized.By Default, Synchronization is done in incremental mode.
Full Synchronization is also available, if needed.
This is to ensure that all files on PATCH filesystem are exact copy of files on RUN Filesystem.
2)Prepares the Database
A new patch edition is created in the database.All code objects in the Patch Edition begin as pointers to code objects in the Run Edition
Objects are only “Actualized” into the Patch Edition when a new revision of the code is applied. Storage objects such as tables are not copied.
This ensures efficient use of space.
Use the below Command to start prepare
$ adop phase=prepare
Prepare phase runs Cleanup from previous cycle if it wasn’t run explicitly. To minimise the execution time of prepare phase, we need to run cleanup explicitly.
Also, submits Online Patching concurrent program (ADZDPATCH),o prevent online patching incompatible concurrent programs from executing.