SELECTstatements and is effectively a Full Refresh. Subsequent syncs will use the logs to determine which changes took place since the last sync and update those. Airbyte keeps track of the current log position between syncs.
UPDATEstatements appear the same way as records from
INSERTstatements. We support different options for how to sync this data into destinations using primary keys, so you can choose to append this data, delete in place, etc.
ab_cdc_lsn(postgres and sql server sources) is the point in the log where the record was retrieved
ab_cdc_log_pos(specific to mysql source) is the file name and position in the file where the record was retrieved
ab_cdc_updated_atis the timestamp for the database transaction that resulted in this record change and is present for records from
ab_cdc_deleted_atis the timestamp for the database transaction that resulted in this record change and is only present for records from
UPDATE. For example, changes made from
ALTERwon't appear in logs and therefore in your destination.
DELETEstatements only contain primary keys. All other data fields are unset.