VSA Accounting

[trs]

How does one refer to VSAs in the accounting queries in sql.conf?

I figure it would just be the name of the attribute from the
dictionary, but what if there's a VSA name the conflicts with a
standard name (e.g. "Realm")? Is there a prefix that can be used to
differenciate them?

Also, what's a better method: extending the radacct table to include
these VSAs, or using a table specifically for the VSAs?