Legacy data archival options for HCM

We're looking for pointers on how to consolidate and pull all legacy systems(data) into a single source.

We had some recent acquisitions and the legacy teams used EBS, UKG and DayForce. We're now having to maintain multiple legacy databases and instances.

For all the migrations, we only pulled Active employee information and a limited Info for Terminations.

To review/access any historical data, we're having to look at multiple sources.

 

Is there a strategy or an Oracle product/module which would aid us to consolidate all legacy systems/data?

How are other customers managing similar requirements for acquisitions?

Appreciate any pointers on the same.