[multistage] Null Check Predicates Not Pushed Down #10381
Description
Repro:
explain plan for select count(*) from userAttributes_OFFLINE WHERE (deviceOS is null)
Execution Plan
LogicalAggregate(group=[{}], EXPR$0=[$SUM0($0)])
LogicalExchange(distribution=[hash])
LogicalAggregate(group=[{}], EXPR$0=[COUNT()])
LogicalValues(tuples=[[]])
explain plan for select count(*) from userAttributes_OFFLINE WHERE (deviceOS is null or deviceOS IN ('macos'))
Execution Plan
LogicalAggregate(group=[{}], EXPR$0=[$SUM0($0)])
LogicalExchange(distribution=[hash])
LogicalAggregate(group=[{}], EXPR$0=[COUNT()])
LogicalProject(deviceOS=[$5])
LogicalFilter(condition=[=($5, 'macos')])
LogicalTableScan(table=[[userAttributes_OFFLINE]])
cc: @walterddr : Is this because we don't create types with nullability in TypeFactory?
related to: #10148