Orkestra.Projection.Checkpoint (orkestra v0.2.0)

Copy Markdown View Source

Ecto schema for persisting a projector's position and halt status.

Each row tracks a single named projector's last successfully processed event position and whether the projector is currently halted due to a dead-lettered event (ERR-03).

Fields

  • :projector_name — unique identifier for the projector (e.g., "MyApp.OrderProjector")
  • :last_position — the global monotonic integer position of the last successfully applied event (D-02). Starts at -1 (no events processed). Enables positional lag arithmetic: head_position - last_position.
  • :haltedtrue when the projector has exhausted retries and parked an event; the projector must not advance until the dead-letter entry is resolved (ERR-03).
  • :halted_at — timestamp of when the projector entered the halted state.
  • :updated_at — auto-managed timestamp of the last checkpoint update.

Table

projection_checkpoints — created by Orkestra.Projection.Migration.up/0.