> My conclusion is that a query can update some internal states of HiveServer2, > affecting DAG generation for subsequent queries.
Other than the automatic reoptimization feature, there's two other potential suspects. First one would be to disable the in-memory stats cache's variance param, which might be triggering some residual effects. hive.metastore.aggregate.stats.cache.max.variance I set it to 0.0 when I suspect that feature is messing with the runtime plans or just disable the cache entirely with set hive.metastore.aggregate.stats.cache.enabled=false; Other than that, query24 is an interesting query. Is probably one of the corner cases where the predicate push-down is actually hurting the shared work optimizer. Also cross-check if you have accidentally loaded store_sales with ss_item_sk(int) and if the item i_item_sk is a bigint (type mismatches will trigger a slow join algorithm, but without any consistency issues). Cheers, Gopal
