如何在hsqldb中对大型表执行高效的group by / sum聚合？

In my HSQL DB I have a large (>10M rows) cached table 'Products' where each Product has a 'groupId' and 'value' column. There is also an index on the groupId colum. In another cached table 'Groups' (also large, >1M rows) I need to store all aggregated values of all Products that belong to this group. So basically my query would look like this:In my HSQL DB I have a large (>10M rows) cached