My suggestion would be to join on the ID and make it an extract (top right had corner), and potentially add some extract filters to cut down on the number of rows. Once you have that done and you go to your first sheet, it will start creating an extract database. Now this can take some time, but once it pulls in all of the rows the performance improvement on the sheets will be much greater. Let me know if this helps!
I'll try that, thanks!
In the meantime, is there any way to "feed" my second query from my second datasource with a result from the first datasource?
I this case, I'd like to use the IDS from the MYSQL result as a clause "WHERE ID IN (<MYSQL_IDS>)" in the Teradata one.
Thanks in advance!