PostgreSQL: VACUUM FULL or CLUSTER?

I'm nearly out of disk space because of a query that tried to update every row in a huge table. I don't have enough space for CLUSTER (though it would barely fit if I dropped indexes first and recreated them afterwards).

How can I estimate how long VACUUM will take? How about VACUUM FULL? How do the three (with CLUSTER) compare in terms of开发者_StackOverflow社区 running time and disk usage?

It's PostgreSQL 8.3.

use cluster, until 8.4 vacuum full is broke. if it takes to long you might as well dump and reload the table.