Large Table Updates, causing memory exhaustion. Is a transaction wrapper the answer?

Hello all,

I am new to the PostgreSQL world.

I am creating a new DB with ALOT of records, for instance one table that I
need to do updates on is about 5.5GB in size.

Doing a simple operation to uppercase the records, I keep exhausting the
memory of the backend.  I'm thinking that writing my SQL statement within a
Transaction is the correct method... Is it? If so, what is the best way to
loop it through all the records, such that I again do not get into
exhausting the memory available.

The original SQL statement I have been using is
"UPDATE table_name SET field_1 = UPPER(field_1);"

Any help would be appreciated, and thank you in advance.

-Michael Miyabara-McCaskey