Function is_sum_window_function

engine/src/parser/expression_utils.cpp:684–689

Due to `sum` window aggregation the OVER clause is repeated two times from Calcite something like: CASE(>(COUNT($0) OVER (PARTITION BY $1), 0), $SUM0($0) OVER (PARTITION BY $1), null:INTEGER)

// something like:
// CASE(>(COUNT($0) OVER (PARTITION BY $1), 0), $SUM0($0) OVER (PARTITION BY $1), null:INTEGER)
bool is_sum_window_function(std::string expression) {
	size_t num_over_clauses = StringUtil::findAndCountAllMatches(expression, "OVER");
	if (num_over_clauses == 2) return true;
	
	return false;
}

// Due to `avg` window aggregation the OVER clause is repeated three times from Calcite
// something like: