*/
public void performCustomDBIndexDeletions(WGDatabase db) throws IOException, WGIllegalArgumentException, InterruptedException {
// check if db is not a full contentstore
// this method is only supported for none fullcontentstores
if (db.hasFeature(WGDatabase.FEATURE_FULLCONTENTFEATURES)) {
throw new WGIllegalArgumentException("Method performCustomDBIndexDeletions() is unsupported for full featured contentstores.");
}
// check if db is already indexed
if (!_indexedDbs.containsKey(db.getDbReference())) {
throw new WGIllegalArgumentException("Cannot perform deletions on database '" + db.getDbReference() + "'. Database is not yet indexed. Ensure performCustomDBIndexUpdates() has been called first.");
}
// collect currently indexed document keys for this db
Set currentlyIndexedDocuments = new HashSet();
BooleanQuery query = new BooleanQuery();