dbxcompress
Function
Description
dbxcompress compressed EMBOSS B+tree format index files. By
default, the indexing applications in EMBOSS compress all index
files.
Indexes modified by dbxuncompress and indexes prior to
EMBOSS 6.4.0 are uncompressed.
Algorithm
The B+tree index files contain discrete pages with a known maximum
size, filled from the first byte with a count of index terms.
dbxcompress reads all pages, calculating the free space at the
end of each page, and then rewrite the pages to disk removing all free space.
The final page is always written in full. This allows index reading to
assume the maximum page size in all cases without reading beyond the
end of file.
Uncompressed index files are required for updating an existing
index. Compressed index files provide more efficient storage and
retrieval.
Usage
Command line arguments
Input file format
dbxcompress reads the index files for a database created with
an older version of one of the 'dbx' indexing programs, or
uncompressed with dbxuncompress.
Output file format
dbxcompress rewrites the index files in compressed form.
Data files
None.
Notes
None.
References
None.
Warnings
None.
Diagnostic Error Messages
None.
Exit status
It always exits with status 0.
Known bugs
None.
Author(s)
History
Target users
Comments