mg_invf_rebuild(1)

NAME
mg_invf_rebuild - Rebuild an mg inverted file with or without skips.

SYNOPSIS
mg_invf_rebuild [-h]
[ -0 | -1 [ -k num ] | -2 [ -s num ] [ -m num ] ]
[ -d directory ] -f name

DESCRIPTION
mg_invf_rebuild builds a new inverted file, with or without skipping, from an old inverted file. This file uses *.invf.ORG and *.invf.idx.ORG as the source from which it builds *.invf and *.invf.idx. If *.invf.ORG or *.invf.idx.ORG do not exist, the program renames *.invf or *.invf.idx to *.invf.ORG or *.invf.idx.ORG as appropriate. The old inverted file may contain skipping. This means that it is possible to delete the *.ORG files after the new inverted file is built.

OPTIONS
Options may appear in any order.

-h  This displays a usage line on stderr.

-0  This generates a non-skipped inverted file. This option is normally only needed if the *.ORG files have been deleted.

-1  This generates a skipped inverted file. The -k num argument specifies the number of pointers hopped over with each skip.

-2  This option generates a skipped inverted file. The skipped inverted file is built so that it is `optimal' for ranking using a specific number of accumulators. Each term in the inverted file has a different skip length. The arguments -s and -m control the sizes of the skips.

-k num
    This specifies the number of pointers that should be hopped over with each skip. This option is only valid if -1 is specified.

-m num
    This specifies the intended number of accumulators that will be used when ranking queries are done on the collection.

-s num
    This specifies the minimum size for skips. If the calculation of the optimal skip size results in a number smaller than num, the skip size is set to num.

ENVIRONMENT

MGDATA
    If this environment variable exists, then its value is used as the default directory where the mg(1) collection files are. If this variable does not exist, then the directory “.” is used by default. The command line option -d directory overrides the directory in MGDATA.

FILES

*.invf
    Inverted file.

*.invf.ORG
    Original inverted file.

*.invf.idx
    The index into the inverted file.

*.invf.idx.ORG
    The original index into the inverted file.

*.invf.dict.build
    Compressed stemmed dictionary.

SEE ALSO
mg(1), mg_compression_dict(1), mg_fast_comp_dict(1), mg_get(1), mg_invf_dict(1), mg_invf_dump(1), mg_passes(1), mg_perf_hash_build(1), mg_text_estimate(1), mg_weights_build(1), mgbilevel(1), mgbuild(1), mgdictlist(1), mgfelics(1), mgquery(1), mgstat(1), mgtic(1), mgticbuild(1), mgticdump(1), mgticprune(1), mgticstat(1).