> Sequential values tend to index well because they don't require large sections of the index to be realigned Erm... What? I don't understand this sentence at

> Sequential values tend to index well because they don't require large sections of the index to be realigned Erm... What? I don't understand this sentence at all, and I know well how indexing works. > [MySQL performance] Notice the nearly consistent insertion time of a long integer vs. the UUID. Oh boy. You just found out that (a) MySQL is a subpar product and (b) that inserting 4 or 8 bytes is faster than inserting 36 bytes. How about inserting 8 bytes (int64) vs. inserting 16 bytes (deicated UUID type) in PostgreSQL? > Auto incremented integers will almost always be smaller, meaning scans against tables/records will be more efficient. And this is because...? You know how B-trees work, do you? And you do know that you very rarely need a sequential iteration over artificial key in a database?