Report - Best design to pull data from HANA and Non-Hana DB

Hello,

We have a requirement to build a report in UI5 where data is coming from System1 (on HANA DB) and System2 (on Oracle DB). The amount of data is huge from System1 but very less from System2. How best we should design this report w.r.t. performance?

Below are the options I think of:

1. Create Hana XS application (XSJS ) in System1 and make a call to System2 to get the information and show in UI.

2. Create Hana XS application (XSOData) in System1 and OData (v2) on System2. From UI make a call to get the data from System2.

3. Create a UI5 application in Netweaver Gateway (new system) and get the data from both systems (hub deployment) and show the result in UI.

Please let us know your thoughts.

Thanks,