AngaraStream
AngaraStream provides Change Data Capture (CDC) capabilities for AngaraBase.
start_offset semantics
The start_offset parameter controls which events are delivered to a new subscription.
| Value | Behaviour |
|---|---|
'latest' (default) | Skips historical events. Only new events published after the subscription is created are delivered. |
'earliest' | Delivers all events currently in the buffer, starting from the oldest retained event. |
Buffer overflow with earliest
If the internal event buffer has been partially evicted before 'earliest' is processed,
AngaraBase returns StreamGapError. In this case, drop the subscription and recreate it
(the gap cannot be recovered without a re-seed).
-- recreate after StreamGapError
SELECT angara_stream_unsubscribe('my-sub');
SELECT angara_stream_subscribe('my-topic', 'my-sub', start_offset => 'earliest');