ASE 15, the optimizer, and a quick config tip

A customer recently called after an ASE 12.5 to ASE 15 upgrade, complaining of performance issues of certain, (previously) quick queries. I didn't have this one in my back pocket then, and should have:

We increased statement cache, and enabled literal autoparameterization, the problem dissolved.

Apparently, the optimizer is a lot smarter with 15, but also works much harder. Caching sql statements made a huge difference.