Hi,

>From the man page for mnesia

dirty_prev(Tab, Key) -> Key | exit({aborted, Reason})

This function works exactly mnesia:dirty_next/2 but returns the

previous object in Erlang term order for the ordered_set table

type. For all other table types, mnesia:dirty_next/2 and mne-

sia:dirty_prev/2 are synonyms.

cheers

Chandru

On 19/09/05, Erik Reitsma (RY/ETM) <erik.reitsma> wrote:

> Hi all,

>

> Using mnesia, is there an efficient way to find the smallest entry in a table with a key equal to or less than a given key?

>

> So suppose that I have keys 10, 23, 33, 34, 56, 100 and I look for 26, I want to get 23 back. If I look for 23, I should get 23.

>

> I could select all entries smaller than or equal to my key, and then take the largest of those, but it seems like I would get an intermediate list that may consist of the entire table (i.e. if my key is larger than the largest key in the table).

>

> I could make my own binary search (the keys are integers anyway), but I wondered if there would be a more elegant way.

>

> Regards,

> *Erik.

>

>