Tag: Context switch

I recently stumbled upon a curious query on a customer's productive Oracle database: SELECT USER FROM SYS.DUAL Two things caught my attention: The query was executed many billions of times per month, accounting for about 0.3% of that system's load. That's 0.3% for something extremely silly! I don't think that customer would ever qualify the … Continue reading Beware of Hidden PL/SQL to SQL Context Switches →