Let's say I am using PHP to connect to MySQL. I am connected and have selected a certain database where 99.9% of my data resides.
If I wanted to pull something from a second database, residing on the same server.
Is it faster/less resource-intensive to open up a new, second connection to MySQL and select the second database, or am I better off changing to that database at the time I need the data, then changing back to resume the normal flow?