Netezza update based on a table join

I have worked with SQL Server for more than 8 years, and I'm used to writing queries like this when I'm trying to update data based on query involving table joins:

update tableA
set col1 = 0
from tableA A
join tableB B on A.id = B.bid
where b.name = 'x'

So after years of writing this kind of sql, which comes so natural to me, imagine my surprise when I moved to Netezza and wrote a query like this to update some data and I get an error message that says:

ERROR [HY000] ERROR:  Update canceled: attempt to update a target row with values from multiple join rows

Reading the message, it's trying to tell me that based on my join, I'm getting a one to many match on the rows I'm trying to delete from. So? SQL Server never complained about it. There are many cases where we do a join on tables with 1 to many relationships and do deletes/updates.

But Netezza doesn't like it. You can of course rewrite the query to have an IN clause. But there's also another funky way (at least funky to me) to achieve the desired results:


update tableA A
set col1 = 0
from tableB B
where A.id = B.bid
and b.name = 'x'

For a 3 table join:

update tableA f
set msid = 0
from tableB d, tableC t
where A.p_sid = D.d_sid
and A.t_sid = t.t_sid
and D.day_start = '2012-01-03'
and T.time_minute = 10