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....
Does the real-time sync work for Postgres instances that are tens of GB and thousands of tables across schemas?
1. A small footprint process / docker container that can index or sync your data source with ES that is operationally simple vs relying on application layer logic,
2. Supports on-the-fly transformations with Javascript, as well as configuration of mappings (so if you want to set a specific analyzer on your Text fields, or set type mappings),
3. Works with a wide variety of sources - Postgres, MySQL, SQL Server, MongoDB, JSON, CSV, Elasticsearch and more coming soon.