# InexactError when saving compressed CSV file (but not if I save it uncompressed) **URL:** \ **Category:** General Usage\ **Tags:** question, csv, zip\ **Created:** [June 10, 2025, 2:01pm UTC](https://discourse.julialang.org/t/inexacterror-when-saving-compressed-csv-file-but-not-if-i-save-it-uncompressed/129784 "2025-06-10T14:01:12Z")\ **Posts on this page:** 4\ **Page:** 1

**Author:** ![sylvaticus](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/sylvaticus/32/203883_2.png) [@sylvaticus](https://discourse.julialang.org/u/sylvaticus)\ **Post date:** [June 10, 2025, 2:01pm UTC](https://discourse.julialang.org/t/inexacterror-when-saving-compressed-csv-file-but-not-if-i-save-it-uncompressed/129784/1 "2025-06-10T14:01:12Z")

x is a 15M x 243 DataFrame: ```julia julia> x 14259735×243 DataFrame Row │ C R Y pr_m1_yl4 pr_m2_yl4 pr_m3_yl4 pr_m4_yl4 p ⋯ │ Int64 Int64 Int64 Float64 Float64 Float64 Float64 F ⋯ ──────────┼───────────────────────────────────────────────────────────────────── 1 │ 1 1 1984 135.01 159.569 134.448 25.8061 ⋯ 2 │ 1 1 1985 57.1593 66.5214 182.197 28.1082 1 3 │ 1 1 1986 136.758 149.088 108.003 34.1564 4 │ 1 1 1987 121.977 85.8327 64.9958 95.0051 5 │ 1 1 1988 197.148 78.5767 69.6241 36.9885 ⋯ 6 │ 1 1 1989 93.3988 130.05 127.21 50.8063 7 │ 1 1 1990 150.033 39.6072 122.061 55.024 1 8 │ 1 1 1991 158.353 105.28 103.605 50.3801 ⋮ │ ⋮ ⋮ ⋮ ⋮ ⋮ ⋮ ⋮ ⋱ 14259728 │ 669 609 2011 10.3363 44.7045 76.2623 76.8465 ⋯ 14259729 │ 669 609 2012 37.849 22.5278 76.5935 11.6821 1 14259730 │ 669 609 2013 74.8778 35.5059 19.4006 45.5431 14259731 │ 669 609 2014 150.525 69.9397 32.5978 44.1507 14259732 │ 669 609 2015 70.5953 55.0444 103.461 78.7517 ⋯ 14259733 │ 669 609 2016 28.8887 44.8978 3.20769 38.7676 14259734 │ 669 609 2017 52.9068 68.933 111.106 33.3569 14259735 │ 669 609 2018 44.0931 23.2465 76.31 18.3548 ``` If I save it uncompressed, it works, producing a ~56GB file: ```julia CSV.write("xclim.csv",x) ``` However, if I try to save it zipping (as inthe CSV doc example), I get an inexact error: ```julia z = ZipFile.Writer("xclim.zip") f = ZipFile.addfile(z, "xclim.csv", method=ZipFile.Deflate) x |> CSV.write(f) # error here after a while close(z) ``` ```julia ERROR: InexactError: trunc(UInt32, 4298836469) Stacktrace: [1] throw_inexacterror(::Symbol, ::Vararg{Any}) @ Core ./boot.jl:750 [2] checked_trunc_uint @ ./boot.jl:772 [inlined] [3] toUInt32 @ ./boot.jl:856 [inlined] [4] UInt32 @ ./boot.jl:896 [inlined] [5] convert(::Type{UInt32}, x::Int64) @ Base ./number.jl:7 [6] setproperty!(x::ZipFile.WritableFile, f::Symbol, v::Int64) @ Base ./Base.jl:52 [7] unsafe_write(f::ZipFile.WritableFile, p::Ptr{UInt8}, nb::UInt64) @ ZipFile ~/.julia/packages/ZipFile/yQ7yx/src/ZipFile.jl:682 [8] unsafe_write @ ./io.jl:803 [inlined] [9] write @ ./io.jl:837 [inlined] [10] writecell @ ~/.julia/packages/CSV/XLcqT/src/write.jl:306 [inlined] [11] (::CSV.var"#114#115"{…})(val::Float64, col::Int64, nm::Symbol) @ CSV ~/.julia/packages/CSV/XLcqT/src/write.jl:362 [12] eachcolumn @ ~/.julia/packages/Tables/8p03y/src/utils.jl:75 [inlined] [13] writerow(buf::Vector{…}, pos::Base.RefValue{…}, len::Int64, io::ZipFile.WritableFile, sch::Tables.Schema{…}, row::DataFrameRow{…}, cols::Int64, opts::CSV.Options{…}) @ CSV ~/.julia/packages/CSV/XLcqT/src/write.jl:358 [14] (::CSV.var"#107#108"{…})(io::ZipFile.WritableFile) @ CSV ~/.julia/packages/CSV/XLcqT/src/write.jl:225 [15] with(f::CSV.var"#107#108"{…}, io::Any, append::Bool, compress::Bool) @ CSV ~/.julia/packages/CSV/XLcqT/src/write.jl:294 [16] #write#106 @ ~/.julia/packages/CSV/XLcqT/src/write.jl:215 [inlined] [17] write(file::ZipFile.WritableFile, itr::DataFrame; append::Bool, compress::Bool, writeheader::Nothing, partition::Bool, kw::@Kwargs{}) @ CSV ~/.julia/packages/CSV/XLcqT/src/write.jl:199 [18] write @ ~/.julia/packages/CSV/XLcqT/src/write.jl:162 [inlined] [19] #101 @ ~/.julia/packages/CSV/XLcqT/src/write.jl:161 [inlined] [20] |>(x::DataFrame, f::CSV.var"#101#102"{@Kwargs{}, ZipFile.WritableFile}) @ Base ./operators.jl:926 [21] top-level scope @ ~/.julia/dev/GenFSM/dev_local/autoerncode_clim_nyears.jl:121 Some type information was truncated. Use `show(err)` to see complete types. ``` Could be a memory issue (I have 64 GB on my laptop).. ? ---

**Author:** ![Sukera](https://avatars.discourse-cdn.com/v4/letter/s/ce7236/32.png) [@Sukera](https://discourse.julialang.org/u/Sukera)\ **Post date:** [June 10, 2025, 2:13pm UTC](https://discourse.julialang.org/t/inexacterror-when-saving-compressed-csv-file-but-not-if-i-save-it-uncompressed/129784/2 "2025-06-10T14:13:33Z")

I’m surprised that this doesn’t have a better error message, but I think the reason is that your data is simply too large - the original ZIP format has a maximum size of 4GB due to being a 32-bit format. > **[ZIP (file format) | ZIP64](https://en.m.wikipedia.org/wiki/ZIP_(file_format)#ZIP64)** > > The original .ZIP format had a 4 GB (232 bytes) limit on various things (uncompressed size of a file, compressed size of a file, and total size of the archive), as well as a limit of 65,535 (216-1) entries in a ZIP archive. In version 4.5 of the specification (which is not the same as v4.5 of any particular tool), PKWARE introduced the "ZIP64" format extensions to get around these limitations, increasing the limits to 16 EB (264 bytes). In essence, it uses a "normal" central directory entry for a... ---

**Author:** ![sylvaticus](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/sylvaticus/32/203883_2.png) [@sylvaticus](https://discourse.julialang.org/u/sylvaticus)\ **Post date:** [June 10, 2025, 2:16pm UTC](https://discourse.julialang.org/t/inexacterror-when-saving-compressed-csv-file-but-not-if-i-save-it-uncompressed/129784/3 "2025-06-10T14:16:29Z")

ok, thank you.. I have read that page, but I thought that that limit was only on very old zip implementations, and modern implementations had 16 exabytes as limit… Which are other options to save in a compressed way large DataFrames ? EDIT: I managed to get a 5GB tgz using command line (I am in Linux), but I would prefer to have a OS independent way on my code… EDIT2: It seems the standard way to read/write compressed CSV files is to use GZip: ```julia using DataFrames, CSV, CodecZlib a = DataFrame(a=rand(4000),b=rand(4000)) CSV.write("a.csv.gz",a;compress=true) a_copy = CSV.read("a.csv.gz",DataFrame) a == a_copy # true ``` Strange it isn’t so easy to find it… I will now try to use it with my real dataset… ---

**Author:** ![TimG](https://avatars.discourse-cdn.com/v4/letter/t/82dd89/32.png) [@TimG](https://discourse.julialang.org/u/TimG)\ **Post date:** [June 10, 2025, 3:08pm UTC](https://discourse.julialang.org/t/inexacterror-when-saving-compressed-csv-file-but-not-if-i-save-it-uncompressed/129784/4 "2025-06-10T15:08:58Z")

You might try ZipArchives.jl. I don’t think it has this 4GB limitation. > Currently, ZipArchives has the following benefits over ZipFile: > > 1. Full ZIP64 support: archives larger than 4GB can be written.