[sunjain]

Using UUID(or anything other than sequentially increasing numbers) for primary keys is a good idea because when you have high number of concurrent inserts happening, if you have a sequentially increasing primary key(implemented via a b-tree index), the inserts into index will result in hotspot(as all the inserts will be at the end, in the same place). Whereas if it is random number (like UUID), the entry into indexes will happen at different places thus avoiding hot spots.

[sandGorgon]

isnt a hotspot a good thing? since it is localized data, ergo less cache misses. is the complexity of an insert >>> cache miss penalty.

[Someone]

Yes, but with many treads modifying the same structures, you end up doing a lot of locking.

So, your system would not be memory bandwidtht constrained, not because it has many threads using roughly the same memory blocks, but because it has one thread at a time working on those memory blocks.