Replace
replace overwrites destination tables on every successful load.
Use it for small sources, development sources, or sources where a full reload is expected. Treat it as destructive.
Append
append inserts new rows and does not update existing rows.
Use it for append-only event or transaction streams. Append requires a confirmed cursor field.
Incremental
incremental fetches rows after a cursor value and merges them by primary key.
Use it when records can be inserted and later updated. Incremental requires a cursor field and primary key. REST incremental loads also require a cursor query parameter.
Operator checks
- Run Scan before append or incremental SQL loads.
- Confirm cursor and key fields before saving or running append/incremental sources.
- Watch Monitoring after the first run.
- Take a backup before changing load modes on production data.