This bool member is redundant -- I would argue that the existing "int32_t m_groupByColumnCount" is also redundant and could be calculated on-the-fly -- and maybe cached in a local variable if referenced repeatedly. Maybe both of these could be replaced with a "get..." accessor that looked at the member list sizes. Now is a good time to do this for m_groupByColumnCount because it now may have two meanings -- number of group by expressions and number of base columns used in group by expressions, so now is the time to be careful how we use the value.