Per
http://<DelphixEngineIP>/api/#database the refresh action takes one object: RefreshParameters. Clicking that link, we see that there is a subtype specific for Oracle. Click that link. We can see from that page that there are only two required properties: type (which is the name of the object) and timeflowPointParameters. So far we know our object looks like this:
{
"type": "OracleRefreshParameters",
"timeflowPointParameters":
}
So let's click on the timeflowPointParameters link. We can see there are five subclasses. Clicking on each one will give you a brief summary at the top. But for this case, let's choose TimeflowPointSemantic. This allows us to specify time using the semantic LATEST_SNAPSHOT or LATEST_POINT. Since you specified LATEST_POINT above, we'll use that. This Object has three required properties: type (required on every object), location (LATEST_POINT), and container (which is the reference of the object you are copying, in this case a database). Since I don't know the reference of your database, I will just makeup a value: ORACLE_DB_CONTAINER-1
So now we know our JSON body looks like this:
{
"type": "OracleRefreshParameters",
"timeflowPointParameters": {
"type": "TimeflowPointSemantic",
"container": "ORACLE_DB_CONTAINER-1",
"location": "LATEST_POINT"
}
}