Usually there is a setting called index_granularity, which tells the index how many keys it should save. So for example if the index_granularity is 5000, it will save 1 key every 5000 keys and so on. I don't there is anything to optimize here tbh but I am not 100% sure.

I don’t see how they are contradicting? The entire table is in the clustered index and it’s stored as one row per leaf. Both statements are correct. And yes, for an innodb engine, there are no disk pointers. Did that answer your concern?

If we have a composite index like this idx(a,b,c). A leftmost prefix is a or ab or abc and so on. Any query pattern than can be covered by a leftmost prefix of the index can in fact utility this index. Is that more clear?

Good point. You’re correct, but I think the author’s definition of “very short” strings is definitely way less than 255. Also, a note throughout the book, it’s referencing mysql 5.7 (at least for the version I have read). They don’t differ on this particular detail tho.

Abdelaziz Sliem I think hashnode blocks links comments.

Thanks Akef. Yes, you're right, will edit the article soon.

Thank you! Glad you enjoyed it.

Thank you! Glad you enjoyed it.

Thank you! Glad you like it. You can checkout the follow up article on how facebook managed to cut costs by integrating a new system for cold storage and move Haystack to serve warm storage purposes only. You can find the article in the series.

Apoorv Tyagi Where can I find their discord server tho :see-no-evil:?