Hi,
I have an ordered_set in Mnesia where the records look like this:
:request_id, # String, the primary key
:campaign_id, # String, used often for filtering
:call_id, # String
The following function returns the records ordered by the primary key, ascending, as expected:
:mnesia.dirty_match_object({:request, :_, "A", :_})
However, if I add an index for the second attribute (campaign_id), the records are returned in the reverse order (descending).
Is this expected?
I couldn’t find a way to choose between ascending and descending order when creating the index.
Of course I can reverse the records myself at the application level, but it doesn’t seem right.
And in fact I only need the first record (the table holds one queue per campaign_id), so I could take the last record using Enum.at/2 or Enum.fetch/2, but they are O(n) anyway.
Thanks for any help.
