Transaction log full

Hi,

I have two tables tb1(KEY,IDS,col2,col3,col4) and tb2(key,col) each table has 90 milion records and i am updating tab2 data to tb1 using KEy coulmn

UPdate tb1

set IDS=col from tb2

where tb1.KEy=tb2.key

In an execute sql task i am getting an error message stating:

[Execute SQL Task] Error: Executing the query "UPDATE    dbo.HES_OP_1112_test2
SET              H..." failed with the following error: "The transaction log for database 'QualityDB is full. To find out why space in the log cannot be reused, see the log_reuse_wait_desc column in sys.databases". Possible failure reasons: Problems with the query, "ResultSet" property not set correctly, parameters not set correctly, or connection not established correctly.

can any one help in solving this problem.

thanks

kind reagrds

Ravilla