2 large databases - worth merging into 1?

Question

I have 2 large databases that were sharded before. I now have removed the sharding and have created a new database with all of the data except for the tables that were originally sharded. Is it worth importing this data into the new database, or keeping them as seperate entities that I can just scan through? We are talking around 60million records in each sharded table, of which there are 2 tables.

Also, whilst I have an empty table, should I be adding indexes which weren't thought of when the database was originally constructed and now too large to add them?

Answer 1

I have decided to merge the databases. I took a good look at what indexes were missing and adding them whilst the table was empty. These indexes have improved the speed and efficiency of the large tables.