Joins are severely misunderstood and often incorrectly used. I've seen code that had the wrong join and would return 1,000s of rows which then had to be programatically squished down into the data we actually wanted. Some hand crafted SQL usually fixes this
Also some ORMs write dreadful SQL where it comes to joins
A badly written join (or collection of joins) will take a longer time to run that will, when the system is under load, backlog other queries. If these errant queries make up a significant portion of your queries then it will hit performance significantly
It's not the joins themselves just the incorrect use of them
Also some ORMs write dreadful SQL where it comes to joins
A badly written join (or collection of joins) will take a longer time to run that will, when the system is under load, backlog other queries. If these errant queries make up a significant portion of your queries then it will hit performance significantly
It's not the joins themselves just the incorrect use of them