The query processor in Adaptive Server 15.0 is self-tuning, requiring fewer interventions than earlier versions. It also relies less on worktables for materialization since, between steps, the engine supports data flow. However, you can use more worktables when Adaptive Server determines that hash and merge operations are effective.
These are configuration parameters included with Adaptive Server 15.0 that affect optimization:
max repartition degree
max resource granularity
optimization timeout limit
optimization goal
prod-consumer overlap factor (Adaptive Server 15.0.1 and later)
min pages for parallel scan (Adaptive Server 15.0.1 and later)
Adaptive Server 15.0 changes the group by algorithm, and you cannot use set statistics io on with parallel plans.
