most of it i think is just focus. its alot of work to pull together an OLAP and an OLTP database and they are very different workloads. the one place where you

most of it i think is just focus. its alot of work to pull together an OLAP and an OLTP database and they are very different workloads. the one place where you do start to get into fundamental issues is consistency. the planner can certainly identify read-only transactions and statically remove some conflicts. but whatever scheme you are using (locks, mvcc, optimistic) is going to struggle the more concurrent overlapping transactions there are. since OLAP transactions are very long lived and touch alot of things - they are pretty hostile co-residents with the OLTP traffic.