SelectWithUnionQuery (children 1) ExpressionList (children 1) SelectQuery (children 2) ExpressionList (children 1) Function substringUTF8 (children 1) ExpressionList (children 2) Function materialize (children 1) ExpressionList (children 1) Literal \'\' Literal Int64_-9223372036854775808 TablesInSelectQuery (children 1) TablesInSelectQueryElement (children 1) TableExpression (children 1) Function numbers (children 1) ExpressionList (children 1) Literal UInt64_7