Re:SQLBolt – Interactive lessons and exercises to learn SQL
by stouset on Thursday July 15, 2021 @11:50AM
(#27846138)
I’ve seen applications go down hundreds of times from pulling entire tables locally to compute on them. I’ve seen maybe once where an application grew so successful that scaling the database became an extremely challenging topic.
And even in that case, I/O and contention were inevitably the problems. Not CPU.
I’ve similarly heard myths that you should be judicious when writing indexes because they can affect insertion performance. I’ve again seen hundreds of cases where under-indexing killed performance and zero where over-indexing caused problems.
99.9% of the time, you’re not the crazy special case. And if somehow you are, the solutions required are going to be nuanced and involve a ton of specific measurement. It’s widely unlikely you’ll accidentally avoid these problems through something like this.
And even in that case, I/O and contention were inevitably the problems. Not CPU.
I’ve similarly heard myths that you should be judicious when writing indexes because they can affect insertion performance. I’ve again seen hundreds of cases where under-indexing killed performance and zero where over-indexing caused problems.
99.9% of the time, you’re not the crazy special case. And if somehow you are, the solutions required are going to be nuanced and involve a ton of specific measurement. It’s widely unlikely you’ll accidentally avoid these problems through something like this.