Joining data from two tables in MySQL (running MAMP on Mac)

[sdaityari]

I have two tables basic_data_1 and basic_data_2. Each has a field identifier. I want to update the data from basic_data_2 into basic_data_1. I am writing the following query.

UPDATE basic_data_1 b1
    INNER JOIN basic_data_2 b2
        ON b1.identifier = b2.identifier
SET b1.hh_size = b2.hh_size, b1.hh_type = b2.hh_type;

This query keeps on running (I guess there is some error which leads to an infinite loop!)

If I add the clause WHERE b1.identifier = (SELECT identifier FROM basic_data_1);, I get the following error:
ERROR 1093 (HY000): You can't specify target table 'b1' for update in FROM clause.

Basically I need all matching rows updated. Can someone help my update my query?

(Note: Both tables have around 100000 rows)

[r937]

write the equivalent SELECT statement, then do an EXPLAIN on it

are there any indexes on the tables?