Lesson Summary
- Explain how Plan Variants address performance fluctuations in parameterized queries caused by variable data distributions.
- Describe the limitations of caching only one execution plan for parameterized queries and how this can lead to suboptimal performance.
- Outline how Plan Variants enable SAP HANA to cache multiple plans for parameterized queries based on the selectivity of table filters.
- Summarize the cluster creation process in Plan Variants, including how the optimizer evaluates predicates, compiles plans, and associates filter values.
- Utilize the M_SQL_PLAN_VARIANTS and M_SQL_PLAN_VARIANT_STATISTICS monitoring views to monitor active Plan Variants and view corresponding execution statistics.
- Recognize the performance improvements achieved with Plan Variants, including reduced performance fluctuations and ensured stable query performance.