randomly, but after filtering by the criteria in the WHERE part of the query. This can actually be useful sometimes if all non-aggregate fields contain the same

randomly, but after filtering by the criteria in the WHERE part of the query. This can actually be useful sometimes if all non-aggregate fields contain the same value (though I wouldn't actually rely on it, since whether this is allowed depends on how the database is configured, and it makes it easy to introduce errors by changing the query)