user { # User
  n1: circle label:"Start Materialized View"
  n2: diamond label:"Receive Materialized View event"
  n5: rectangle label:"Record Materialized View outcome"
  n9: rectangle label:"Monitor Materialized View status"
  n13: circle label:"End Materialized View"
  n1.handle(right) -> n2.handle(left)
  n2.handle(bottom) -> service.n3.handle(top) [label="Yes/Approved"]
  n5.handle(bottom) -> app.n6.handle(top)
  n9.handle(bottom) -> app.n10.handle(top)
  n2.handle(right) -> database.n4.handle(top) [label="No/Rejected"]
}

app { # App
  n6: rectangle label:"Monitor Materialized View status"
  n10: rectangle label:"Monitor Materialized View status"
  n6.handle(bottom) -> service.n7.handle(top)
  n10.handle(bottom) -> service.n11.handle(top)
}

service { # Service
  n3: rectangle label:"Validate Materialized View conditions"
  n7: rectangle label:"Monitor Materialized View status"
  n11: rectangle label:"Monitor Materialized View status"
  n7.handle(bottom) -> database.n8.handle(top)
  n11.handle(bottom) -> database.n12.handle(top)
  n3.handle(right) -> user.n5.handle(top)
}

database { # Database
  n4: rectangle label:"Execute Materialized View action"
  n8: rectangle label:"Monitor Materialized View status"
  n12: rectangle label:"Monitor Materialized View status"
  n12.handle(right) -> user.n13.handle(bottom)
  n8.handle(right) -> user.n9.handle(left)
  n4.handle(right) -> user.n5.handle(left)
}