Productivity of roundup can be raised if substring search for the all
text search would be possible.

I am attaching to hacks that have been in use at Intevation a few
years ago. One is probably very inefficient, the other specific to 
backends with the LIKE sql statement.

Hacks done by Frank Koormann:
2008-roundup_indexer_rdbms_pattern_full_textsearch.patch
2008-roundup_indexer_dbm_pattern_search.diff