JSON DDL request failed - pipeline rowset is missing - azure-analysis-services

Question

Objective
Refresh a partition using a query (override). Using these as a guide:
https://www.sqlbi.com/articles/using-process-add-in-tabular-models/
https://gist.github.com/dgosbell/a7bc9fe9ff5a99fdb4df5819b8760217#file-refresh-with-override-example-txt
Apparently the MS example is not correct: https://learn.microsoft.com/en-us/bi-reference/tmsl/refresh-command-tmsl#examples
TMSL Script
{
"refresh" : {
"type" : "add",
"objects" : [{
"database" : "dbname",
"table" : "tblname"
}
],
"overrides" : [{
"partitions" : [
{
"originalObject" : {
"database" : "dbname",
"table" : "tblname",
"partition" : "partname"
},
"source" : {
"query" :
"SELECT * FROM source.view WHERE date_field = '2014-12-06'"
}
}
]
}
]
}
}
Error Message
The JSON DDL request failed with the following error: Failed to execute XMLA. Error returned: 'The Process command for partition 'partname' in table 'tblname' cannot be executed because the pipeline rowset is missing.
'..
Technical Details:
RootActivityId: 89a6f9ac-e5d4-4eaa-b049-455190039b4b
Date (UTC): 6/28/2019 3:20:36 PM
0: PFError::SetLastError() line 2158 + 0x0 (sql\picasso\engine\src\pf\eh\pferror.cpp)
1: PFSetLastError() line 2906 + 0x0 (sql\picasso\engine\src\pf\eh\pferror.cpp)
2: ConvertExceptionsToPFResult<<lambda_764f81a97ea803a6bb1663c7971ce151> >() line 424 + 0x34 (sql\picasso\engine\src\pf\kernel\shared\pfshmacros.inl)
3: PFSetLastErrorExTag() line 3461 + 0x2e (sql\picasso\engine\src\pf\eh\pferror.cpp)
4: 0x00007FFAB599CC7E (symbolic name unavailable)
Other Info
Executed on SSMS directly and in Powershell (via Runbook) with same error message.
Question
What does this error message mean exactly? (It is very hard to find
helpful documentation.) Or, is there an alternative solution to refreshing
a partition using a query override?

Answer 1

You can only use either a Query or M partition sources
If you are using an M partition source the syntax is:
"source":{
"type":"m",
"expression":"…"
}
And if you are using a Query partition source the syntax is:
"source":{
"type":"query",
"query":"…",
"dataSource":"…"
}