[erlang-questions] Mnesia record with composite key and QLC questions

Leon de Rooij <>
Wed May 20 13:50:58 CEST 2009


Thanks everyone for the helpful insight. I've already tried putting  
100k users in mnesia (still with the compound primary key) which took  
a few minutes (disc_copy) with no extra indexes but the primary key,  
but searching it is blazingly fast, even with relatively complex  
queries..

I really like the zero data impendance and the way functions are used  
in qlc:q, I can imagine things like storing IP adresses as binary in  
the db and then have a function to query all records that fall within  
a given subnet (I tried this once in SQL, and it didn't turn out very  
nice..) Or use the re module in queries.. So very cool :-)

Kind regards,

Leon



On May 19, 2009, at 2:03 AM, John Haugeland wrote:

>> RAM copies are basically limited by available memory.
>>
>> On 32-bit systems, this will be either 3GB or 4GB.
>
> Or a little under 2g, if it's non-PAE 32-bit Windows, which limits
> each process to 2^31 bytes, where a little under is "minus whatever
> else the erlang VM is doing".
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