Identifying database from which a hit sequence came from after blastdb_aliastool

Question

[navela78]

I am using blastdb_aliastool to create custom databases (say custom_db = db1 + db2) to perform blast. Once I get blast results from custom_db is there a way to find which blast database (db1 or db2) a certain hit came from?

[GenoMax]

What does the database identifier say in the result? Original name or alias?

[navela78]

The blast result file contains "Database: custom_db" (i.e.) the alias in the beginning of the file and the end of the file. Is this what you meant by database identifier? There is no database identifier for each hit unless I am missing to set some blast option properly.

[GenoMax]

Not sure how big the databases are but perhaps you can uniquely tag the sequence headers in the databases (_db1/2 to be able to get this information from the result.

[navela78]

The databases are big but adding the db name in the headers seems to the only option right now. Thanks for your response.