Long Query Times
I have a table with 23.5 million rows and 20 columns.  I updated the table to set one of the columns to `null`.  This query took an hour to complete.  Granted, I don't have an amazingly fast database server, but is this update time normal?  I didn't have an index on this table when I ran the update.  How much would that have helped?

Thanks in advance!
Long Query Times
===

I have a table with 23.5 million rows and 20 columns.  I updated the table to set one of the columns to `null`.  This query took an hour to complete.  Granted, I don't have an amazingly fast database server, but is this update time normal?  I didn't have an index on this table when I ran the update.  How much would that have helped?

Thanks in advance!