Prooph Event Stream Projection from merged streams event ordering

PersonListProjection.php

<?php

MergedStreamIterator.php#L107�\^�]8;;�\ array:2 [
  0 => array:2 [
    0 => Prooph\EventStore\Pdo\PdoStreamIterator�]8;;file:///var/www/rewotec-personnel/vendor/prooph/pdo-event-store/src/PdoStreamIterator.php#L27�\^�]8;;�\ {#90
      -selectStatement: PDOStatement {#115
        +queryString: """
          SELECT * FROM `_d2588481fc670c20e905cc363144708b697ce254` USE INDEX(ix_query_aggregate)\n
          WHERE `no` >= :fromNumber\n
          ORDER BY `no` ASC\n
          LIMIT :limit;
          """
      }
      -countStatement: PDOStatement {#91
        +queryString: """
          SELECT COUNT(*) FROM `_d2588481fc670c20e905cc363144708b697ce254` USE INDEX(ix_query_aggregate)\n
          WHERE `no` >= :fromNumber
          """
      }
      -messageFactory: Prooph\Common\Messaging\FQCNMessageFactory�]8;;file:///var/www/rewotec-personnel/vendor/prooph/common/src/Messaging/FQCNMessageFactory.php#L20�\^�]8;;�\ {#145}
      -currentItem: false
      -currentKey: -1
      -batchPosition: 1
      -batchSize: 10000
      -fromNumber: 5210
      -currentFromNumber: 5210
      -count: null
      -forward: true
    }
    1 => "person_stream"
  ]
  1 => array:2 [
    0 => Prooph\EventStore\Pdo\PdoStreamIterator�]8;;file:///var/www/rewotec-personnel/vendor/prooph/pdo-event-store/src/PdoStreamIterator.php#L27�\^�]8;;�\ {#87
      -selectStatement: PDOStatement {#89
        +queryString: """
          SELECT * FROM `_c1670165c005fb3d12618b6eb4d4c71cf1767117` USE INDEX(ix_query_aggregate)\n
          WHERE `no` >= :fromNumber\n
          ORDER BY `no` ASC\n
          LIMIT :limit;
          """
      }
      -countStatement: PDOStatement {#88
        +queryString: """
          SELECT COUNT(*) FROM `_c1670165c005fb3d12618b6eb4d4c71cf1767117` USE INDEX(ix_query_aggregate)\n
          WHERE `no` >= :fromNumber
          """
      }
      -messageFactory: Prooph\Common\Messaging\FQCNMessageFactory�]8;;file:///var/www/rewotec-personnel/vendor/prooph/common/src/Messaging/FQCNMessageFactory.php#L20�\^�]8;;�\ {#145}
      -currentItem: false
      -currentKey: -1
      -batchPosition: 1
      -batchSize: 10000
      -fromNumber: 8068
      -currentFromNumber: 8068
      -count: null
      -forward: true
    }
    1 => "service_contract_stream"
  ]
]

Came from:

• https://twitter.com/webdevilopers/status/1321571279519010818

We are running a projection reading from two streams. I'm dumping the data on the read model methods. As you can see the "contract" comes first with created_at = 2020-02-10 12:53:44, THEN comes the "person" with created_at = 2020-02-10 12:53:07. Any idea?

No #2068 is the "Person Stream" "PersonAdded" Event created at "2020-02-10 12:53:07.000000" and no #4580 is the related "Contract Stream" "ContractEntered" Event created at "2020-02-10 12:53:44.000000".
Code: $projector->fromStreams('person_stream', 'service_contract_stream')...

The stream order itself is correct - _d2588481fc670c20e905cc363144708b697ce254 = "Person Stream" at 0 and _c1670165c005fb3d12618b6eb4d4c71cf1767117 = "Contract Stream" at 1 -

How should the behaviour be in a single stream? It looks like it projection runs using the no order instead of created_at. So I guess we have to rewrite our wrongly ordered manually migrated stream.

We rewrote the event stream ordered by "created_at" and re-setting the no. The projection now looks as expected.

If I see this correctly then writing a projection fromStreams does not work if one of the streams has inconsistent ordering between no and created_at. Though this should not happen when correctly using the lib. But the mentioned sort does not seem to solve it.