utils

Scripts for recreating the Dassie database

Dependencies

The implementation of parse-lcsh-and-create-db depends on Dave Beckett's Redland librdf library. You will probably need to install it on your system. If you are using MacPorts on macOS, the following will do it:

port install redland
port install redland-bindings +python27

(Note: if you omit the +python27, the second step above will lead to an error about "no variants selected".) At the time these notes were written, the version available from MacPorts was 1.0.16.

Running the scripts

The process is basically this:

1. Unzip the copy of authoritiessubjects.nt.skos.gz in the directory ../dassie/data, or (if you are trying to use a new edition of the LCSH subject headings RDF file) download a copy from http://id.loc.gov/download/.
2. If there is no authoritiessubjects.nt.skos in the current directory, create a symbolic link to the file in ../dassie/data:

   ln -s ../dassie/data/authoritiessubjects.nt.skos
   

3. Start MongoDB's mongod server process:

   ./start-empty-mongodb
   

   If this encounters any problems, it will report a failure. The problem must be corrected before going on.
4. Assuming that the file authoritiessubjects.nt.skos is in the current directory, execute the following command:

   ./parse-lcsh-and-create-db authoritiessubjects.nt.skos
   

   If the above runs successfully, you should see a long list of outputs that begin like this:

   Adding metadata
   Initial pass and database creation
   1000 triples
   *** skipping children's subject id sj96005973
   *** skipping children's subject id sj96005656
   ...
   

5. Once the process is finished, you can kill the database server because it is not needed anymore. To do this, find the process identifier reported during step 3 and issue the following command:

   kill PID
   

   where PID is the process id of the mongod process as reported by start-empty-mongodb.

If all went well, there will be a database directory named lcsh-db in the current directory. This can be used to replace the lcsh-db directory in the Dassie directory ../dassie/lcsh-db. It can also be saved as a database dump, and used to replace the file lcsh-dump.tgz in ../dassie/data.