Does airbyte delete existing data before syncing new one with full refresh replication?

Yes, in Airbyte's Full Refresh - Overwrite mode, the existing data in the destination is deleted before syncing the new data from the source. This means that any data that has been removed from the source after an old sync will also be deleted in the destination table. This is in contrast to the Incremental sync mode, which does not sync data that has already been synced before. Here is an example of how the data in the destination changes before and after the sync: Before the sync:

| Languages | | --- | | Python | | Java |

New data:

| Languages | | --- | | Python | | Java | | Ruby |

After the sync:

| Languages | | --- | | Python | | Java | | Ruby |

As you can see, the new data (Ruby) is added, and the existing data (Python and Java) remains the same. If any data was removed from the source (for example, if Python was removed), it would also be removed from the destination after the sync. You can find more information about this in the [Airbyte documentation](https://docs.airbyte.com/understanding-airbyte/connections/full-refresh-overwrite).