12.1.0.2 : Questions on Patching

Hi,

We have upgraded test instance of EBS database from 11.2.0.1. to 12.1.0.2.0.    This is a 2 node rac environment .   The version of grid is 12.1.0.2.   We are going through the following documentation and need some clarification.

) Apply the following patches for environments with the In-Memory option enabled:

For all UNIX/Linux platforms:

Patch 6880880- the latest OPatch version for 12.1.0.

Patch 20698050- 12.1.0.2.7

Patch 19475484- Take the 12.1.0.2.7 version of the patch.

What does this mean?    should we set inmemory_size ?  

If we apply patch 20698050 (12.1.0.2.7)   , should we also patch  Grid to 12.1.2.0.7 or higher

Please let me know.

Thanks

Ram