Mysql: Are join tables locked on insert?

Question

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.

Answer 1

it will be locked while inserting. Insertion through transaction will be much better.

Answer 2

I found a solution. When setting transaction-isolation= to "READ-COMMITTED", read statements won't lock a table.

See: http://harrison-fisk.blogspot.ch/2009/02/my-favorite-new-feature-of-mysql-51.html