[erlang-questions] mnesia tables with few attributes
Andras Georgy Bekes
Wed Dec 12 15:36:54 CET 2007
It seems that mnesia has a rather strange restriction:
"The table must have at least one extra attribute in addition to the
Ok, in general mnesia tables hold records, so a record has a name, and a
record contains at least two values. If you have only one value, why
would you need a record? --- This is logical.
But, what if I only want a 'set' --- a set in the mathematical sense, I
just want to have elements, insert and remove them, check for
membership, etc. And I need persistence and transactions... Do I really
need 2 extra fields besides the key (the only value I need)?
Is there some real reason why a table with 1 or 2 columns are
prohibited, or just because it's use is... illogical?
Any idea to (ab)use mnesia to implement a 'set'?
PS: OK, I can make a table with 2 extra fields, it isn't performance or
space critical, just ugly :-)
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