Does CloudQuery access any application data in my cloud?

No. CloudQuery only accesses metadata and configuration data. It never pulls data from your application databases or cloud storage files.

What happens when I run two (or more) syncs? Will the second sync remove resources that no longer exist from the database?

There are currently three types of write modes in destination plugins: overwrite-delete-stale, overwrite, and append. The default is overwrite-delete-stale.

  • In overwrite-delete-stale data will be upserted based on primary keys and stale data will be deleted by deleting any data fetched by the same previous source config.
  • In overwrite data will be upserted based on primary keys and it will be up to the user to setup recurring task to delete stale data.
  • In append, old rows are never deleted or updated - every sync adds new rows.

In overwrite and append mode, you can distinguish between rows from different syncs by inspecting the _cq_sync_time column.