# Dict loaded from jld file very long time... Why 22 seconds?

**URL:** <https://discourse.julialang.org/t/dict-loaded-from-jld-file-very-long-time-why-22-seconds/1629>\
**Category:** General Usage\
**Tags:** jld\
**Created:** [January 21, 2017, 6:58pm UTC](https://discourse.julialang.org/t/dict-loaded-from-jld-file-very-long-time-why-22-seconds/1629 "2017-01-21T18:58:18Z")\
**Posts on this page:** 1\
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**Author:** ![felix](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/felix/32/604_2.png) [@felix](https://discourse.julialang.org/u/felix)\
**Post date:** [January 22, 2017, 11:21am UTC](https://discourse.julialang.org/t/dict-loaded-from-jld-file-very-long-time-why-22-seconds/1629/5 "2017-01-22T11:21:25Z")

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The `Dict{K,V}` notation means its keys have type `K` and its values have type `V`. In your slow example, `Dict{Int64,Any}`, the keys are `Int64` but there is no available type information about the values (hence they are recorded as the `Any` type). It may perform faster if, instead of `Any`, the values are all of the same concrete type _and this is known to the compiler_. Notice that’s what happened in your fast-performing example `Dict{Int64,Float64}`, all the values were guaranteed to be of the same type `Float64`. This situation is called “strictly-typed”, unlike the case where values have `Any` type. Having strict type information can allow Julia to make significant optimisations.

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