If you want database support (required for prewikka),
you should install a preludedb package such as preludedb-mysql and
then do something like the following:

/usr/bin/mysqladmin create prelude
echo "GRANT ALL PRIVILEGES ON prelude.* TO prelude@'localhost' IDENTIFIED BY 'prelude';" | /usr/bin/mysql -h localhost
/usr/bin/mysql -h localhost -u prelude prelude -p < /usr/share/libpreludedb/classic/mysql.sql
/usr/bin/mysql -h localhost -u prelude prelude -p < /usr/share/libpreludedb/classic/addIndices.sql