erlang - Which is more expensive to the RAM, A query list comprehension, or a mnesia index_read? -



erlang - Which is more expensive to the RAM, A query list comprehension, or a mnesia index_read? -

i trying read fragmented mnesia table hold big number of records in near future. these reads may other keys other primary key of table.

which of 2 options more efficient? query list comprehension, or mnesia index read?

well, indices require more disk space. each table fragment, mnesia create separate index file. however, index reads more efficient experience.

qlc consume more memory @ run time when results of query many. require utilize query cursors. advise utilize index read. index read not expensive @ ram because normal read though mnesia has consult index file first. qlc when comes doing complex table relationships , evaluations of homecoming values in batch. however, introduces processing costs , memory when results many. note qlc uses mnesia:select/1,2 , 4 (which specific one, not sure) know select operation makes mnesia traverse whole table in serach records.

mnesia index read improve query list comprehension

erlang

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