[erlang-questions] mnesia fragmentation

wde <>
Tue Jun 30 02:40:05 CEST 2009


forgot my second question, my test was wrong and I found the answer in the mailing list

thank you

wde


======= le 29/06/2009, 19:04:38 vous écriviez: =======

>Hello all,
>
>I'm trying to play with (and understand) the mnesia fragmentation feature.
>
>-> what is the interest of the node_pool property ? I understand that we use it during the initial fragmentation activation in order to distribute the replicas. But once activated I don't understand the role of the node_pool. When we  want to add fragments (add_frag) we have to specify the nodes (or the distribution) to use, and we can add fragment on a node which is not in the node_pool, same thing for fragment replicas. Someone could say me  when  the node_pool is used ?
>
>In other words, what happen if we use nodes for fragmentation without adding them in node_pool ?
>
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>-> If a fragment (not replicated) is no more available (after a node goes down for example) , and I try to delete the table, mnesia aborts the operation. The solution I found is to recreate a table with the lost fragment name : 
>
>
>()> mnesia:delete_table(test_db).
>{aborted,{no_exists,test_db_frag2}}
>
>()> mnesia:create_table(test_db_frag2,[]).
>{atomic,ok}
>
>()> mnesia:delete_table(test_db).
>{atomic,ok}
>
>Is there a better solution ?
>
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>Thank you for your time and your help.
>
>wde
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>erlang-questions mailing list. See http://www.erlang.org/faq.html
>erlang-questions (at) erlang.org
>
>

= = = = = = = = = ========= = = = = = = = = = =
			
wde

30/06/2009



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