I am starting a blog post series on using indexes — or tables — as queues. I had this series in the back of my mind for some time. This started a few years back when I worked on optimizing a row deletion job (I do not call this a purge job, to avoid confusion with the InnoDB Purge). Such jobs can be generalized to using indexes (or tables) as queues (this is fairly cryptic, I come back to this). In this post, I explain why queries, which are expected to be fast, might become slow, and as the title of this post implies, it is related to the InnoDB Purge.
