Re: query to find gaps in sequential indexes causes CPU spikes

[Rick James]

> I've used EXPLAIN and it is using my index to do a range look up and estimates a single row for the dependant subquery.
May I please see the EXPLAIN?

> could have as much as million rows where column1 = 10.
So it might have to read most of that million? That takes CPU time (assuming everything is cached, and you don't pound on the disk).

> cpu can spike to 50+%
Your machine has 2 cores?

> finding gaps
What do you mean? Given 1,2,6,7,9,10,11,12,15; you want to say there is a gap from 3-5 and 8-8 and 13-14 ? If so, I think that can be done in one or two passes, no "iterations". The output would be:
3 5
8 8
13 14