Approximately 18 million file entities have only partial file metadata. All
have a sha1 (hex), but many are missing file size, md5, mimetype, etc.

At least a few thousand of these are additionally *not* `application/pdf`
mimetype based on actually retrieving the file and sniffing the file type.
These are added earlier to the catalog likely based on CDX mimetype, which is
server-reported and can be incorrect.

## QA Testing

    ./fatcat_import.py --editgroup-description-override "backfill of full file-level metadata for early-imported papers" file-meta -
    => Counter({'total': 1000, 'update': 1000, 'skip': 0, 'insert': 0, 'exists': 0})

    # Identical command, verifying that don't double-insert:
    => Counter({'total': 1000, 'skip-existing-complete': 1000, 'skip': 0, 'insert': 0, 'update': 0, 'exists': 0})

Two additional file-level cleanups should probably be done at the same time:

Partial wayback URL timestamps, for cases where we have the full timestamped URL. Eg:

    https://web.archive.org/web/2017/http://www.geoamazonia.net/index.php/revista/article/download/51/pdf_38
    https://web.archive.org/web/20170922010835/http://www.geoamazonia.net/index.php/revista/article/download/51/pdf_38
    https://qa.fatcat.wiki/file/4udmm4zd4bgfhnaaycqoztgfgm
    https://qa.fatcat.wiki/file/k73il3k5hzemtnkqa5qyorg6ci
    https://qa.fatcat.wiki/file/7hstlrabfjb6vgyph7ntqtpkne

Live-web URLs identical except for http/https flip or other trivial things (much less frequent case):

    http://eo1.gsfc.nasa.gov/new/validationReport/Technology/JoeCD/asner_etal_PNAS_20041.pdf
    https://eo1.gsfc.nasa.gov/new/validationReport/Technology/JoeCD/asner_etal_PNAS_20041.pdf

    http://homepages.math.uic.edu/~rosendal/PapersWebsite/BanachMinimalExamples.pdf
    http://homepages.math.uic.edu:80/~rosendal/PapersWebsite/BanachMinimalExamples.pdf
    https://qa.fatcat.wiki/file/h2wx6re5fjhx7c6duifzskeo6u
    https://qa.fatcat.wiki/file/vw7divmjwveftn4djj2cp32n4i

Which bot to use? Let's do `sandcrawler-bot`.

Trying a larger batch to see what database size increase is going to look like,
and whether single-threaded is going to be too slow:

    # before: Size:  517.87G

    time zcat /srv/fatcat/datasets/fatcat_file_partial.file_meta.json.gz | head -n500000 | pv -l | ./fatcat_import.py --editgroup-description-override "backfill of full file-level metadata for early-imported papers" file-meta -
    => 145m18.615s

    # after: 518.47G
    # delta: 600 MB

A million records would take about 5 hours, so 100 hours total, or 4 days. Let's do parallelism.

Total size increase estimated as 24 GBytes. It all adds up!

    time zcat /srv/fatcat/datasets/fatcat_file_partial.file_meta.json.gz | tail -n500000 | pv -l | parallel -j8 --round-robin --pipe -q ./fatcat_import.py --editgroup-description-override 'backfill of full file-level metadata for early-imported papers' file-meta -
    => real    32m53.935s

## Production Import

Before Size: 624.63G

    export FATCAT_API_AUTH_TOKEN... # sandcrawler-bot

    # start small
    time zcat /srv/fatcat/datasets/fatcat_file_partial.file_meta.json.gz | pv -l | head -n1000 | parallel -j8 --round-robin --pipe -q ./fatcat_import.py --editgroup-description-override 'backfill of full file-level metadata for early-imported papers' file-meta -

    # full batch
    time zcat /srv/fatcat/datasets/fatcat_file_partial.file_meta.json.gz | pv -l | parallel -j8 --round-robin --pipe -q ./fatcat_import.py --editgroup-description-override 'backfill of full file-level metadata for early-imported papers' file-meta -

    => 18.1M 20:53:32 [ 241 /s]

    Counter({'total': 2234159, 'update': 2234111, 'skip-existing-complete': 48, 'skip': 0, 'insert': 0, 'exists': 0})
    (etc, 8x)

After Size: 653.69G (+29GB or so)