1. Does it sync deltas or do you have to import the whole table each time?
2. Does it listen for changes to a table or does it require a manual invocation?
3. Can you explain more about the algorithm/implementation?
The way it works is after the initial import if you are using the `--tail` option, it listens to further changes via oplog. More on setting oplog access over here - https://github.com/appbaseio/abc/blob/dev/docs/importer/adap...
For Postgres, similarly a replication role and a replication slot needs to be created for decoding the write ahead log. More on that here - https://github.com/appbaseio/abc/blob/dev/docs/importer/adap....
This seems like a good primer on replication slots - https://postgresqlspace.wordpress.com/2015/06/18/replication....