optional_depends "libdbi"     "--enable-libdbi"  "--disable-libdbi"  "to link drivers against libdbi"
optional_depends "sqlite"     "--with-sqlite3"   "--without-sqlite3" "to build the SQLite3 driver"
optional_depends "mysql"      "--with-mysql"     "--without-mysql"   "to build the MySQL driver"
optional_depends "postgresql" "--with-pgsql"     "--without-pgsql"   "to build the postgresql driver"
optional_depends "freetds"    "--with-freetds"   "--without-freetds" "for Tabular Data Stream support"
