I'm developing a plugin with a lot of SQL reads and I'd like to optimize it as much as possible. One optimization I'd like like to look into is switching all of my query_read functions to query_read_slave functions.
I've read that query_read_slave() should be used when timing is not vital (
source).
- Is there a performance increase even when there's no slave DB?
- What are some examples of situations where timing would be vital vs. not vital?
I've also read that "you only use query_read_slave when you have more than 1 query running together" (
source).
- Is this true? If so, can somebody explain this further?
If you guys can answer some of these questions, I would be very grateful.