feat: add an analysis of affected store paths if we delete the proposed nixos images
8224dee unverified metadata
license: mit
language:
- en
tags:
- nix
- nixos
size_categories:
- 100M<n<1B
- 1B<n<10B
pretty_name: Nix Cache Dataset
configs:
- config_name: inventory
data_files: datasets/inventory-2026-01-06T01-13Z.parquet
- config_name: narinfos in the inventory
data_files: datasets/narinfos-2026-01-06T01-13Z.parquet
- config_name: narinfos in the inventory - nixos images only
data_files: datasets/narinfos-nixos-images-2026-01-06T01-13Z.parquet
- config_name: store paths affected by the removal of nixos images
data_files: datasets/narinfos-nixos-images-dangling-refs-2026-01-06T01-13Z.parquet
- config_name: buildstepoutputs
data_files: datasets/buildstepoutputs-2025-12-05-17:38:30Z.csv.zst
- config_name: narinfos in inventory but not in buildstepoutputs
data_files: datasets/inventory-not-in-buildstepoutputs-2025-12-05-17:38:30Z.parquet
Nix Cache Dataset
This repository contains several datasets relating to the contents of https://cache.nixos.org:
Getting started
To make it easier to explore the datasets, a Nix devshell is provided in shell.nix. To enter it, run
❯ nix develop -f shell.nix
[brian@saturn:~/Development/com/github/numtide/nix-cache-dataset]$
If you are a Direnv user, you can also run direnv allow to automatically load the devshell:
❯ direnv allow
direnv: loading ~/Development/com/github/numtide/nix-cache-dataset/.envrc
direnv: using nix
direnv: nix-direnv: Using cached dev shell
direnv: export +AR +AS +CC +CONFIG_SHELL +CXX +HOST_PATH +IN_NIX_SHELL +LD +NIX_BINTOOLS +NIX_BINTOOLS_WRAPPER_TARGET_HOST_x86_64_unknown_linux_gnu +NIX_BUILD_CORES +NIX_CC +NIX_CC_WRAPPER_TARGET_HOST_x86_64_unknown_linux_gnu +NIX_CFLAGS_COMPILE +NIX_ENFORCE_NO_NATIVE +NIX_HARDENING_ENABLE +NIX_LDFLAGS +NIX_STORE +NM +OBJCOPY +OBJDUMP +RANLIB +READELF +SIZE +SOURCE_DATE_EPOCH +STRINGS +STRIP +__structuredAttrs +buildInputs +buildPhase +builder +cmakeFlags +configureFlags +depsBuildBuild +depsBuildBuildPropagated +depsBuildTarget +depsBuildTargetPropagated +depsHostHost +depsHostHostPropagated +depsTargetTarget +depsTargetTargetPropagated +doCheck +doInstallCheck +dontAddDisableDepTrack +mesonFlags +name +nativeBuildInputs +out +outputs +patches +phases +preferLocalBuild +propagatedBuildInputs +propagatedNativeBuildInputs +shell +shellHook +stdenv +strictDeps +system ~PATH ~XDG_DATA_DIRS
brian@saturn ~/..../nix-cache-dataset main* ⇡
❯
The devshell contains a duckdb command which is pre-configured to load some helpful utility functions which reside in
./duckdb/init.sql:
nixbase32which converts a fixed-sizebyte[20]column into nixbase32narURLwhich recovers the URL of a NAR file from it'sfile_hashandcompressioncolumns.
Both are necessary when introspecting any of the narinfo related datasets as their schema was optimized to reduce file sizes.
Contents
The primary datasets below were compiled with Narwal.
datasets/inventory-2026-01-06T01-13Z.parquet
This is a complete inventory of the S3 Bucket which backs the cache as of 2026-01-06T01:13Z and provided by the
S3 Inventory Service. It has the following schema and is ordered by key:
❯ duckdb -c "describe select * from 'datasets/inventory-2026-01-06T01-13Z.parquet'"
┌────────────────────┬──────────────────────────┬─────────┬─────────┬─────────┬─────────┐
│ column_name │ column_type │ null │ key │ default │ extra │
│ varchar │ varchar │ varchar │ varchar │ varchar │ varchar │
├────────────────────┼──────────────────────────┼─────────┼─────────┼─────────┼─────────┤
│ key │ VARCHAR │ YES │ NULL │ NULL │ NULL │
│ size │ BIGINT │ YES │ NULL │ NULL │ NULL │
│ last_modified_date │ TIMESTAMP WITH TIME ZONE │ YES │ NULL │ NULL │ NULL │
│ e_tag │ VARCHAR │ YES │ NULL │ NULL │ NULL │
│ storage_class │ VARCHAR │ YES │ NULL │ NULL │ NULL │
└────────────────────┴──────────────────────────┴─────────┴─────────┴─────────┴─────────┘
Here is the first 10 entries:
❯ duckdb -c "select * from 'datasets/inventory-2026-01-06T01-13Z.parquet' limit 10"
┌──────────────────────────────────────────┬───────┬──────────────────────────┬──────────────────────────────────┬───────────────┐
│ key │ size │ last_modified_date │ e_tag │ storage_class │
│ varchar │ int64 │ timestamp with time zone │ varchar │ varchar │
├──────────────────────────────────────────┼───────┼──────────────────────────┼──────────────────────────────────┼───────────────┤
│ .well-known/pki-validation/gsdv.txt │ 101 │ 2018-09-07 09:35:54+01 │ dcdfef6f1cdfeae2d2c9de7dab84292a │ STANDARD │
│ 000003nzgismzlipaq0jnchpz65d65z7.ls │ 1228 │ 2024-06-21 17:17:36+01 │ bf47b9ab2ea7a795d15107d4dcf64697 │ STANDARD │
│ 000003nzgismzlipaq0jnchpz65d65z7.narinfo │ 1452 │ 2024-06-21 17:17:37+01 │ 34997acded08172170eb1a4cde9456d1 │ STANDARD │
│ 00000c8rdrjqkdxjpm5wrhl6sspapbmn.ls │ 97 │ 2019-11-06 19:35:06+00 │ ae368bafcfb9e5632acc57acf4f2a325 │ STANDARD │
│ 00000c8rdrjqkdxjpm5wrhl6sspapbmn.narinfo │ 905 │ 2019-11-06 19:35:06+00 │ 0bf1c5c76cf15dd07c8c79eca27ebff4 │ STANDARD │
│ 00000in9ndrbpshcibwfgsygx0xq069g.ls │ 329 │ 2025-11-07 18:40:26+00 │ f817f1b476fe0cb82ac2f5dbc19be620 │ STANDARD │
│ 00000in9ndrbpshcibwfgsygx0xq069g.narinfo │ 732 │ 2025-11-07 18:40:28+00 │ 4037fbf8ab5484847756f0839c2c7245 │ STANDARD │
│ 00000jipsrr2nfgn36w04xg2z6hnr7y0.ls │ 323 │ 2024-01-06 07:48:26+00 │ 8a3bad8cb3795080ccd636ef212c1878 │ STANDARD │
│ 00000jipsrr2nfgn36w04xg2z6hnr7y0.narinfo │ 523 │ 2024-01-06 07:48:27+00 │ 997c5c9a6911bfadd7efcb9f845a4082 │ STANDARD │
│ 00000lkv8yz6bsccrp03ppq71mzjdcpv.ls │ 396 │ 2022-05-10 03:33:54+01 │ 3284e9e9e5ae0a2562640e1f20af395d │ STANDARD │
├──────────────────────────────────────────┴───────┴──────────────────────────┴──────────────────────────────────┴───────────────┤
│ 10 rows 5 columns │
└────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┘
`datasets/narinfos-2026-01-06T01-13Z.parquet``
This is a complete download of all .narinfo files within the S3 bucket as of 2026-01-06T01:13Z. It has the following
schema:
❯ duckdb -c "describe select * from 'datasets/narinfos-2026-01-06T01-13Z.parquet'
┌───────────────────────────────┬─────────────┬─────────┬─────────┬─────────┬─────────┐
│ column_name │ column_type │ null │ key │ default │ extra │
│ varchar │ varchar │ varchar │ varchar │ varchar │ varchar │
├───────────────────────────────┼─────────────┼─────────┼─────────┼─────────┼─────────┤
│ hash │ BLOB │ YES │ NULL │ NULL │ NULL │
│ pname │ VARCHAR │ YES │ NULL │ NULL │ NULL │
│ compression │ VARCHAR │ YES │ NULL │ NULL │ NULL │
│ file_hash │ BLOB │ YES │ NULL │ NULL │ NULL │
│ file_size │ UBIGINT │ YES │ NULL │ NULL │ NULL │
│ nar_hash │ BLOB │ YES │ NULL │ NULL │ NULL │
│ nar_size │ UBIGINT │ YES │ NULL │ NULL │ NULL │
│ references │ BLOB[] │ YES │ NULL │ NULL │ NULL │
│ deriver │ BLOB │ YES │ NULL │ NULL │ NULL │
│ deriver_pname │ VARCHAR │ YES │ NULL │ NULL │ NULL │
│ system │ VARCHAR │ YES │ NULL │ NULL │ NULL │
│ signature_domains │ VARCHAR[] │ YES │ NULL │ NULL │ NULL │
│ signature_values │ BLOB[] │ YES │ NULL │ NULL │ NULL │
│ ca_algo │ VARCHAR │ YES │ NULL │ NULL │ NULL │
│ ca_hash │ BLOB │ YES │ NULL │ NULL │ NULL │
│ quirk_references_out_of_order │ BOOLEAN │ YES │ NULL │ NULL │ NULL │
├───────────────────────────────┴─────────────┴─────────┴─────────┴─────────┴─────────┤
│ 16 rows 6 columns │
└─────────────────────────────────────────────────────────────────────────────────────┘
The schema is the same as the contents of a .narinfo file with some notable differences:
StorePathhas been split intohashandpname, with the/nix/store/prefix omitted.- In addition,
hashhas been decoded from its original 32-bytenixbase32format into a 20-byte fixed-sizebyte[20]column to save space. As mentioned in Getting Started, there is anixbase32utility function forduckdbwhich can be used to convert it back into it's original format. URLis not included. Instead, it can be recovered from thefile_hashandcompressioncolumns using thenarURLutility function. Again, this was to save space.quirk_references_out_of_orderindicates whether thereferencescolumn was not canonically sorted as is required by the narinfo format.
Here is an example of using both:
❯ duckdb -c " select nixbase32(hash) as hash, pname, narURL(file_hash, compression) as URL from 'datasets/narinfos-2026-01-06T01-13Z.parquet' where pname like 'nixos-%.iso' limit 10"
┌──────────────────────────────────┬──────────────────────────────────────────────────────────────────────┬─────────────────────────────────────────────────────────────────┐
│ hash │ pname │ URL │
│ varchar │ varchar │ varchar │
├──────────────────────────────────┼──────────────────────────────────────────────────────────────────────┼─────────────────────────────────────────────────────────────────┤
│ 8s2i888nxl44dvrqkszyhm9wagx21cv8 │ nixos-21.11pre-git-aarch64-linux.iso │ nar/01i2cax5rgfirdnqy3gk0fam1jxjqzydlm6fmydqcr2rppzfgpyc.nar.xz │
│ 8s2nl0q5l0qjwj4mdh47b32abd7dkb37 │ nixos-plasma5-23.11pre525972.ace5093e36ab-x86_64-linux.iso │ nar/03wiqhgkgbwr6lz6jlhnq9d4swjahdw32ylixshmpy25wmnhkg83.nar.xz │
│ 8s308z464is6rbnn1wglws37bz5cxhi3 │ nixos-minimal-new-kernel-21.03pre253346.87e9b49fc78-x86_64-linux.iso │ nar/1ppngdicfkydg44hbyc6s77f40qk15a8r370a02yg06y4w7fscp3.nar.xz │
│ 8s37vnmdg68z51s81lp7pfclkp0ljl7v │ nixos-plasma5-21.11.335288.3ddd960a3b5-x86_64-linux.iso │ nar/04pic41qkjib69bl1yk48w5bdnb0jj4jfzljmfxsx3c9sr966m71.nar.xz │
│ 8s4yq0kgvw7d34jzd6j256n8rhqdncag │ nixos-18.03pre-git-x86_64-linux.iso │ nar/11m49i89vpm8mjq2khpiy9p4br3fkvk57nmi6narmxbih9lahg45.nar.xz │
│ 8s4zyq65nl0d5jjd28pvm8rih78khhlx │ nixos-21.03pre-git-x86_64-linux.iso │ nar/00ivaz2lwdvqcg7c64l9ikgk0njcphad4h69z2hvih7xrrzvwbb0.nar.xz │
│ 8s5577gfk2makszs3bnpfzf8h477ywwd │ nixos-minimal-17.03.1730.dad3c2231c-i686-linux.iso │ nar/074d9323apli87919s8rr8rfa0javdqvk24r4siclq1ysg67gp38.nar.xz │
│ 8s580im104kqdf873sc1bqanp5x7mvjn │ nixos-18.09pre-git-x86_64-linux.iso │ nar/0nw2zmxw3bhn9ixx66n9vfhk81qvr88yh1a3dxyv1qi5xbqv8fgz.nar.xz │
│ 8s5wj1h8hcvhiqxghlgblxnsi8lccrs7 │ nixos-graphical-25.11pre819493.4206c4cb5675-x86_64-linux.iso │ nar/0mnwc0lpxf4hllv97gc58rd7m0rkph03cg2b35zmarq1kcd1ihq5.nar.xz │
│ 8s616arfxnpgz8grd3rggm9ahgk5wvn7 │ nixos-minimal-19.09pre174421.b306b4cf1a9-x86_64-linux.iso │ nar/1qxcksrfa9nv10ln5kf2mcx2jndx4hyf34x594779f0lh4rlfw68.nar.xz │
├──────────────────────────────────┴──────────────────────────────────────────────────────────────────────┴─────────────────────────────────────────────────────────────────┤
│ 10 rows 3 columns │
└───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┘
datasets/narinfos-nixos-2026-01-06T01-13Z.parquet
This is a subset of the narinfos-2026-01-06T01-13Z.parquet dataset which is attempting to identify any narinfos related
to NixOS ISOs and other images which have been uploaded to the cache. These are candidates for removal from the cache as
they are stored elsewhere.
It was compiled using ./duckdb/nixos-images.sql;
datasets/narinfos-nixos-images-dangling-refs-2026-01-06T01-13Z.parquet
This is a list of store paths which reference one or more of the store paths contained in datasets/narinfos-nixos-images-2026-01-06T01-13Z.parquet,
which will be affected by their removal from https://cache.nixos.org.
It was compiled using bin/dangling-references.py.
datasets/buildstepoutputs-2025-12-05-17:38:30Z.csv.zst
This is a dump of the buildstepoutputs table taken from Hydra on 2025-12-05T17:38:30Z. It can be thought of as a
record of every output path that Hydra has ever built and looks like this:
❯ head datasets/buildstepoutputs-2025-12-05-17:38:30Z.csv
build,stepnr,name,path
684,2,out,/nix/store/mnkbj3aziazk2ijadn23cpwarm6bfmh8-nixos-install
683,5,out,/nix/store/172yppi4bklbs1cyh91wqwpyyfbkvgds-system-path
684,3,out,/nix/store/dxi8ij2la8in64mclyjslgs04nylcsa2-upstart-manual
685,1,out,/nix/store/isaw8s240isvg06pimbr1wj12wxs9glv-hydra-build
684,4,out,/nix/store/qcpb0179capgcyij03xk6fqhlwbafjr0-upstart-jobs
686,1,out,/nix/store/07syvqz4w8n0z3alfm4kg5i46v3wbidx-checkinstall-1.6.1
686,2,out,/nix/store/1g5nks931nirya16hmw2l1lg0jwazmsw-e2fslibs_1.39+1.40-WIP-2006.11.14+dfsg-2etch1_amd64.deb
686,3,out,/nix/store/0dgvq0q33sniq77kq9150shj0jqllzh0-file_4.17-5etch3_amd64.deb
686,4,out,/nix/store/7f03xxka0l0h623ydvqsjvqf6w1vvhzv-heimdal-1.0.2.tar.gz
datasets/inventory-not-in-buildstepoutputs-2025-12-05-17:38:30Z.parquet
This file contains a list of all the .narinfo files within datasets/inventory-2026-01-06T01-13Z.parquet
(up to 2025-12-05-17:38:30Z) which do not have a corresponding entry in
datasets/buildstepoutputs-2025-12-05-17:38:30Z.csv.zst.
It was compiled using ./duckdb/inventory-not-in-buildstepoutputs.sql;
Subsequently, graphs were generated using bin/graph-inventory-not-in-buildstepoutputs.py and placed in ./graphs:
