# Help improving the speed of a DataFrames operation

**URL:** <https://discourse.julialang.org/t/help-improving-the-speed-of-a-dataframes-operation/107615>\
**Category:** Performance\
**Tags:** performance, query, dataframes\
**Created:** [December 14, 2023, 3:20pm UTC](https://discourse.julialang.org/t/help-improving-the-speed-of-a-dataframes-operation/107615 "2023-12-14T15:20:21Z")\
**Posts on this page:** 1\
**Showing post:** 3

<div class="post-metadata">

**Author:** ![abelsiqueira](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/abelsiqueira/32/47269_2.png) [@abelsiqueira](https://discourse.julialang.org/u/abelsiqueira)\
**Post date:** [December 15, 2023, 9:16am UTC](https://discourse.julialang.org/t/help-improving-the-speed-of-a-dataframes-operation/107615/3 "2023-12-15T09:16:41Z")

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Hi @pdeffebach, I changed it to the following:

```julia
transform!(
        df_cons,
        [:rp, :asset, :time_block] =>
            ByRow(
                (rp, a, time_block) -> begin
                    df = @view df_flows[(df_flows.rp.==rp).&&(df_flows.to.==a), :]
                    coalesce(
                        sum(df.flow .* length.(Ref(time_block) .∩ df.time_block) * 3.14rp),
                        AffExpr(0.0),
                    )
                end,
            ) => :incoming_term,
    )

```

But there are no improvements. The code is wrapped in a function.

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