[lazulicurio]

I don't consider being aware of your data distribution to be "hacking the engine". It's part of a good DBA's job. For any data set of appreciable size you can't treat the data as a black box. Even if you're not clustering the underlying table in postgres the performance of your indices will be heavily affected by data layout.

[marcus_holmes]

I agree. Hacking the ID field to include index data so the storage clustering is a bit more performant is not "treating the data as a black box" to my mind.