large table update

hello, i have a following problem: I have got 130 million row TABLEA
and I need to run this update:
UPDATE TABLEA
SET COLUMNA=(SELECT COLUMNB FROM TABLEB WHERE condition)

I suppose that for every row from TABLEA (80 million times) select statement must be executed, which is terribly slow. Isn't there a better way to write this update? Thank youCould you provide the WHERE clause in detail, pls?|||Originally posted by Coolberg
Could you provide the WHERE clause in detail, pls?

WHERE column from TABLEA=column FROM TABLEB