Handle UUID when import from PostgresQL to OrientDB using ETL - postgresql

Question

I have a graph in PostgresQL with 2 table:
vertex (id:uuid)
edge (from:uuid, to:uuid)
I use etl to transform it to orientdb for vertex:
{
"config": {
"log": "debug"
},
"extractor" : {
"jdbc": { "driver": "org.postgresql.Driver",
"url": "jdbc:postgresql://localhost/test",
"userName": "postgres",
"userPassword": "123456",
"query": "select id from vertex" }
},
"transformers" : [
{ "vertex": { "class": "vertex"} }
],
"loader" : {
"orientdb": {
"dbURL": "PLOCAL:../databases/test",
"dbUser": "admin",
"dbPassword": "admin",
"dbAutoCreate": true,
"dbAutoDropIfExists": false
}
}
}
When browsing the result in OrientDB, it seemed that the value i see in id field is not consistent with the result I got when query in PorgresQL.
Then I run etl for edge:
{
"config": {
"parallel" : true,
"log": "debug"
},
"extractor" : {
"jdbc": { "driver": "org.postgresql.Driver",
"url": "jdbc:postgresql://localhost/test",
"userName": "postgres",
"userPassword": "123456",
"query": "select from, to from edge"
}
},
"transformers": [
{ "merge": { "joinFieldName": "from", "lookup": "vertex.id" } },
{ "vertex": {"class": "vertex", "skipDuplicates": true} },
{ "edge": { "class": "has_edge", "joinFieldName": "to", "lookup": "Vertex.id", "direction": "in" } },
{ "field": { "fieldNames": ["from", "to"], "operation": "remove" } }
],
"loader" : {
"orientdb": {
"dbURL": "PLOCAL:../databases/test",
"dbUser": "admin",
"dbPassword": "admin",
"dbAutoCreate": true,
"dbAutoDropIfExists": false
}
}
}
The debug printed out console there were some edges that etl processor could not lookup references for from or to. This kind of message use uuids from PostgresQL. Since they are not inconsistent with the values I could query in OrientDB, it is hard to figure out which edges causing the problem.
My question is: how could I config my etl to make uuid from PostgresQL import properly to OrientDB?