Do multiple revisions really slow down WordPress?

I have read numerous times that I should clean up my database to keep performance high. Keeping multiple revisions of posts is always cited as a big performance stealer.

I’m suspicious of this claim. I get that the table will be significantly larger with 10 revisions than 2, but will it really be slower in operation? Given that there are indexes (or should be) on the fields you look things up on frequently, queries should still be nearly as quick.

I can’t see any difference in my own sites, but I don’t have that much data. I’m curious at what point, sizewise any improvement would actually start to show up, if indeed one ever does.

I’m not arguing for site owners to up the number of revisions they want to keep, I’m just trying to understand the real world effect, compared to the big performance improvement claims I so often see.

Having 2 revisions or 100,000 will not change front end performance in a default plugin-less WordPress setup

However plugin and theme authors who do not query the database correctly, could end up accidentally searching/querying revisions, which could have some performance issues

Here’s a snippet on it

revisions take up space in your WordPress database. Some users believe that revisions can also affect some database queries run by plugins. If the plugin doesn’t specifically exclude post revisions, it might slow down your site by searching through them unnecessarily