When you load data using HCM Data Loader, you can provide a source key. The source key is a value, usually generated from a legacy environment (PS\EBS), that identifies the record uniquely in that environment. If you specify no source key (for e.g. converting data using user keys or online data entry), then a default source key is generated. You can update both default and locally defined source keys for integration-enabled objects. This topic describes how to update source keys. (As I write this article, current release for Oracle HCM Cloud is Release 12. )

SourceKey.dat

To update the source key associated with any record, you load a SourceKey.dat file. In the file, you supply both a reference to the record to update and the new source-key value.

For e.g.

SourceKey.dat

METADATA|SourceKey|BusinessObject|Component|OldSourceSystemOwner|OldSourceSystemId|NewSourceSystemOwner|NewSourceSystemId
MERGE|SourceKey|Worker|PersonPhone|FUSION|300000001572671|STUDENT1|PH1001_W
MERGE|SourceKey|Worker|PersonAddress|FUSION|300000002451147|STUDENT1|ADDR1001_HOME

Easy to Read Format:

METADATA

SourceKey

BusinessObject

Component

OldSourceSystemOwner

OldSourceSystemId

NewSourceSystemOwner

NewSourceSystemId

MERGE

SourceKey

Worker

PersonPhone

FUSION

300000001572671

PEOPLESOFT

PH1001_W

MERGE

SourceKey

Worker

PersonAddress

FUSION

300000002451147

PEOPLESOFT

ADDR1001_HOME

Please review this article if you are looking for more information on HDL Keys and Integration keymap.  Hope you find it useful.