The keyword lookup services keyword, keyword-or, and keyword-and use a keyword database that is manufactured nightly from the Netlib index files. This database is a full-text index and includes all words in the Netlib index files.
The keyword-literal and keyword-literal-case searches are slower because they do string matching on the index file descriptions themselves.
The keyword searching mechanisms are expected to be changed to use WAIS indexing and searching in the near future.