I got a query inserting some data into a table. The query has a join to another table.
Will this other table be locked while the query is running?

-e-

here is a query like the one i'm using:

```
INSERT INTO table_1
SELECT    t3.first_row,
          t3.second_row
FROM      table_2 t2
          INNER JOIN
          table_3 t3
          ON t2.t3_fk = t3.id
WHERE t3.id IN (1, 2, 3, 4)
AND   t2.created_at  <= '2014-12-21 22:59:59'

```

The query is running in a rails transaction.