Use pgaudit to generate an audit trail. Upgrade to PostgreSQL 9.5 because it is a requirement for pgaudit. pgaudit/analyze can be used to transfer the audit trail into the database, but it seems to be easy to do this with pgaudit directly with some changes to the code.

{
    "probeId":"1000",
    "mmtId":"A4",
    "nebenprobenNr":"10R1",
    "messdauer":10,
    "fertig":false,
    "geplant":true,
    "messzeitpunkt":"2015-02-09T10:58:36"
}