# History Rollups
To keep the number of files on data.everef.net (opens new window) down,
finished years of some datasets are rolled up into a single archive per year.
The year's directory is removed and replaced by one .tar.xz file next to it:
<dataset>/history/<year>/ (removed)
<dataset>/history/<dataset>-<year>.tar.xz (added)
For example, incursions/history/incursions-2023.tar.xz (opens new window).
Only finished years are rolled up. The current year always stays as individual files. Market history and killmails will never be rolled up.
# Contents
- Paths match the data site:
<dataset>/history/<year>/<YYYY-MM-DD>/<file>.json. Extracting several archives into the same directory recreates the original layout. - Data files are plain JSON. The
.bz2compression is removed, along with the.bz2suffix. - Each file's modification time is its original upload time.
- The
index.jsonfiles are included. Their entries still refer to the original.json.bz2names. index.htmlfiles are not included.
# Extracting
tar -xJf incursions-2023.tar.xz
# Older archives
Some archives predate this format:
incursions/history/incursions-2022.tar.xzwars/history/wars-2003.tar.bz2towars-2020.tar.bz2