I remember doing some experiments with the shared cache on the reader connections and notices that it ended up serializing all queries from different connections, much slower than having a share-nothing approach with private cache. Should such behaviour be expected with the shared cache? In any case, I did such experiments quite a while ago, so it was probably some bug in my code, so I will try to do some more experiments again. Do you think the private cache could be related to the original behaviour I experienced?