Extracts a table containing one row per unique keyword found in the database, where a keyword is unique by the keyword itself and the type of keyword it is (author or ISI). The resulting table contains the following columns:
- keyword: The keyword.
- type: The type of the keyword. Keywords are either provided by the authors of the papers, or generated by ISI automatically. See Load ISI File Into Database/KEYWORD for more details.
- occurrences_in_dataset: The number of times this unique keyword occurs in the dataset. Keywords from authors are counted separately from keywords generated by ISI.