howto start table in mnesia?

I have situation when on开发者_如何学编程e of tables rich size 2G and after it I cannot work with this table,

'mynode@localhost' 5> mnesia:dirty_first(my_table). ** exited: {aborted,{badarg,[my_table]}} **

I understand I need apply fragmentation but how to do it in runtime? And main question is - howto start my_table to reduce its size in runtime? (i mean without restart mnesia)

What kind of data are you storing in mnesia ? From what I understand, you are trying to traverse your table , is it ? If you can decide on what will be the maximum amount of data that will be stored in your database , then you can predecide the number of fragments you need while creating the table.

Else if you need to reconfigure your already fragmented database, then check if the below link helps you :: http://www.erlang.org/doc/apps/mnesia/Mnesia_chap5.html