In my meltano tap-oracle use case I do not have columns like "updated_at" for every table. It is also not possible to always add those. I've stumbled upon the pseudo_column ORA_ROWSCN which (as far as i understand) gets used by the extractor if a run is aborted. Would it be possible to also use the ORA_ROWSCN column as a replication_key to enable key-based incremental replication for tables without specific timestamp columns? Thanks in advance

Hi @sebastian_slanitsch, I believe the ORA_ROWSCN is a guesstimate rather than an exact science around change. https://docs.oracle.com/cd/B13789_01/server.101/b10759/pseudocolumns006.htm This is further confirmed here: https://asktom.oracle.com/pls/apex/f?p=100:11:0::::P11_QUESTION_ID:9538262000346546616 On the basis of my reading I think it is too dangerous. You could try log based replication instead given you don't have an incremental key. tap-oracle does support log based replication.

The flip side is I do believe the

tap-oracle

https://hub.meltano.com/extractors/tap-oracle--transferwise/ does utilize ORA_ROWSCN for incremental streams. Now if this is a good idea or not I don't know (I am in the same camp as @steve_clarke on this one)

I have also figured out that the tap uses ora_rowscn. My question is if I can use it as a replication key, since I've tried the standard way and failed.