[erlang-questions] Fetching several ets keys

Hynek Vychodil <>
Thu Feb 9 12:00:21 CET 2012


This code will cause table full scan which usually will be far slower than just
[ V || K <- ["A","B","C","D"], V <- ets:lookup(Tid, K) ]
except very small tables full scan will not be good idea.

On Thu, Feb 9, 2012 at 11:49 AM, Ahmed Omar <> wrote:
> ets:select(Tid, [{{'$1','$2'},[{'==','$1',X}],['$_']}|| X<-
> ["A","B","C","D"]]).
>
>
> On Thu, Feb 9, 2012 at 11:11 AM, dmitry kolesnikov <>
> wrote:
>>
>> You could try
>> ets:select or qlc interface.
>>
>> It table is not big enough then qlc and custom fold function would work:
>>
>> Q=qlc:q([ X || X <- ets:table(mytab)]),
>> qlc:fold(FoldFun, [], Q)
>>
>> Best Regards,
>> Dmitry >-|-|-*>
>>
>>
>> On 9.2.2012, at 11.40, ori brost <> wrote:
>>
>> > Is there any way in ets to fetch values for several keys in 1 call?
>> > i.e. something like
>> >
>> > ets:multi_fetch(Tid, ["A","B","C","D"]) % will fetch all entries with
>> > keys A, B, C, D
>> > _______________________________________________
>> > erlang-questions mailing list
>> > 
>> > http://erlang.org/mailman/listinfo/erlang-questions
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>
>
>
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Hynek Vychodil
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