public-inbox-xcpdb - upgrade Xapian DB formats

            public-inbox-xcpdb [OPTIONS] INBOX_DIR

    public-inbox-xcpdb is similar to copydatabase(1) for upgrading to the
    latest database format supported by Xapian (e.g. "glass" or "honey"),
    but is designed to tolerate and recover from Xapian database
    modifications from public-inbox-watch(1) or public-inbox-mda(1).

        In addition to performing the copy operation, run xapian-compact(1)
        on each Xapian shard after copying but before finalizing it.
        Compared to the cost of copying a Xapian database, compacting a
        Xapian database takes only around 5% of the time required to copy.

        Compared to public-inbox-compact(1), use of this option is
        preferable for gigantic inboxes where the coarse-grained lock
        currently required for public-inbox-compact(1) can cause the
        compaction to take hours at-a-time.

    --reshard=N / -R N
        Reshard the Xapian database on a v2 inbox to "N" shards . Since
        xapian-compact(1) is not suitable for merging, users can rely on
        this switch to reshard the existing Xapian database(s) to any
        positive value of "N".

        This is useful in case the Xapian DB was created with too few or too
        many shards given the capabilities of the current hardware.

    --blocksize / --no-full / --fuller
        These options are passed directly to xapian-compact(1) when used
        with "--compact".

            The default config file, normally "~/.public-inbox/config". See

            The number of documents to update before committing changes to
            disk. This environment is handled directly by Xapian, refer to
            Xapian API documentation for more details.

            Default: 10000

    This tool is intended for admins upgrading Xapian search databases used
    by public-inbox, NOT users upgrading public-inbox itself.

    In particular, it DOES NOT upgrade the schema used by the PSGI search
    interface (see public-inbox-index(1)).

    Feedback welcome via plain-text mail to <>

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    Copyright 2019 all contributors <>

    License: AGPL-3.0+ <>

    copydatabase(1) <>,
    xapian-compact(1) <>,
    public-inbox-index(1) <>