OCP 1Z0 053 202

202.In which two aspects does hot patching differ from conventional patching? (Choose two.) 
A. It consumes more memory compared with conventional patching. 
B. It can be installed and uninstalled via OPatch unlike conventional patching. 
C. It takes more time to install or uninstall compared with conventional patching. 
D. It does not require down time to apply or remove unlike conventional patching. 
E. It is not persistent across instance startup and shutdown unlike conventional patching. 
Answer: AD 

http://docs.oracle.com/cd/E11882_01/server.112/e17157/planned.htm#HAOVW159

4.1.3.1 Online Patching

Online patches are a special type of interim patch or diagnostic patch that you can applywhile the instance remains online. The only time an interim or diagnostic patch should be applied in an online manner is when:

• The patch README indicates that it can be applied in an online manner.

• The patch needs to be applied urgently and database instances cannot be shutdown to apply the regular (offline) version of the patch.

You can perform online patching with any Oracle database using the OPatch command-line utility.

Also, use the following considerations when performing online patching:

• Oracle provides qualified interim and diagnostic patches as combo patches, which contain both an online patch and an offline patch for the same bug fix.

  Thus, you can apply the online patch initially to avoid unplanned downtime. However, because online patches have amemory overhead, you should roll back the online patch and apply the offline patch during scheduled downtime.

• Applying an online patch increases memory consumption on the system because each Oracle process uses more memory from the Program Global Area (PGA) during the patch application. Consider memory requirements before you begin applying an online patch. Each online patch is unique, and the memory requirements are patch-specific. Apply the patch on your test system first so that you can assess the effect of the online patch on your production system and estimate any additional memory usage.