dbxuncompress
Function
Description
dbxuncompress uncompresses EMBOSS B+tree format index files. By
default, the indexing applications in EMBOSS compress all index
files.
Indexes prior to EMBOSS 6.4.0 are uncompressed.
Uncompressed index files are required for updating an existing
index. Compressed index files provide more efficient storage and
retrieval.
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, identifying the end of the used
space and adding calculating the free space at the end of each page
and calculating the new start position for each uncompressed page. It
then rereads the index file, and rewrites the pages to disk expanded
to the full page size.
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.
Usage
Command line arguments
Input file format
dbxuncompress reads the index files for a database created with
one of the 'dbx' indexing programs.
Output file format
dbxuncompress rewrites the index files in uncompressed 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