My current solution is to issue a bunch of queries: > SELECT make, count(*) FROM table WHERE >criteria< GROUP BY make ORDER BY > count(*) DESC LIMIT 3; make count ----------+--------- audi | 50 bmw | 40 vw | 30
SELECT color, count(*) FROM table WHERE >criteria< GROUP BY color ORDER BY count(*) DESC LIMIT 3; color count -----------+------ red | 400 blue | 200 green | 100 Which will give me the top 3 counts of each column im interested in for the >criteria< specified. However, this is starting to become too slow (as there are about 10 of these queries), and therefore I need to write an aggregate function which lets me do: >SELECT count_unique(make), count_unique(color) from table WHERE >criteria<; After reading about aggregate functions, this should be possible, as long as I can use a dictionary/hashmap type for the state<STYPE> argument. Is there such a type in postgresql that can be used in an aggregate function, and if there isn't, how would it be possible to make one? Also, do you think I'm going about this the wrong way, and there is a much better solution that's I've neglected? -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
