he udaf case is unstable reason: when fuzzy enable_pipeline_engine=true, the case of agg function only 1 instance, so not merge the default value, but if instance>1, will merge the default value
he udaf case is unstable reason: when fuzzy enable_pipeline_engine=true, the case of agg function only 1 instance, so not merge the default value, but if instance>1, will merge the default value