I've some data in another database that is outside of the wordpress database on my small mysql installation.

I have heard that it's really a little tricky to obtain data from the different database as wordpress assumes you'll simply want wordpress data.

Becasue it is only one table, can one manage with only developing a mix database view within the wordpress database? Exist performance factors to consider?

I'd just give permission through mysql to permit your wordpress database user to gain access to another table. This works fine.

Two databases:

DB1
Table1
Table2

DB2
Table3
Table4 

Then whatever you do is one thing such as this:

select * from  DB1.table1, DB2,table3 where DB1.field1 = DB2.field1

Hope which makes sense :)