Deleting mnesia tables

[Sean Hinde]

> Sean> Anyone know an easy way to delete a table which one 
> node thinks exists both
> Sean> on itself and on another node, while the other node is 
> down (please don't
> Sean> ask!)?
> 
> You need to remove the other node from the schema before you 
> can delete the table:
> 
>    (one@REDACTED)8> mnesia:create_table(t, [{disc_copies, 
> [one@REDACTED, other@REDACTED]}]).
>    {atomic,ok}
>    (one@REDACTED)9> rpc:call(other@REDACTED, mnesia, stop, []). 
>    stopped
>    (one@REDACTED)10> mnesia:delete_table(t).
>    {aborted,{not_active,"All replicas on diskfull nodes are 
> not active yet",
> 			t,
> 			[other@REDACTED]}}
>    (one@REDACTED)11> mnesia:del_table_copy(schema, 
> other@REDACTED).
>    {atomic,ok}
>    (one@REDACTED)12> mnesia:delete_table(t).                
>          
>    {atomic,ok}
>    (one@REDACTED)13> 

Thanks, Trouble is there are loads of tables on the other node and It is a
lot of work to re-build it all again from the replica.

I've thought over lunch and concluded that mnesia needs a "more rope" mode.
It is good at trying to prevent dumb users from creating a network of
inconsistent schemas, but not quite good enough (e.g. manually upgrade one
node leaving cruft behind on another).

The trouble is that once a live system is inconsistent it is nigh on
impossible to repair it without a major rebuild of at least one node.

I would be interested to see some functions along the lines of:

dire_warning_but_delete_this_table_locally_regardless_of_replicas(Tab).

and such like.

Meanwhile I'm fiddling with dets (but the support guys will want us to do
the job properly..)

Cheers,,
Sean



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