It is good you are thinking this through before using.
While I have never done this, by inspection this is what I would expect:
I think there would be some additional overhead as the Tables are stored in memory with first reference then the memory version is used thereafter (until process or potentially thread stop) whereas the DB based Tables will go through the DBMS access each time. Depending on the DBMS used that would vary I would think.
If there is an access issue I suspect the TABLE Action may error at which point the setting you select in the TABLE Action Error entry (Skip (default), Pad, Error (put the message in the Error DB) will take place.
The difference between Basic and Advanced that I see is you can specify a Stored Procedure to use for the lookup. I imagine that might allow you to return a value which is the cause of the error (such as “can’t connect”, or “not found”, or whatever). Then in your Xlate you can test for error conditions and take appropriate action (perhaps retry the connection or trigger an alert of some kind and dispose of the message in a more intelligent fashion).
Hopefully someone who has also thought this through AND actually utilized the DB lookup (both basic and advanced) can reveal the real facts.
Otherwise you will need to do that experiment an let us all know how it goes.
email: jim.kosloskey@jim-kosloskey.com 29+ years Cloverleaf, 59 years IT - old fart.