Online to find a sm3 Java code, test execution time consuming 1 million times less than 30 seconds,
Write inside a stored procedure by vernier reading 1 million records and the records of dac field to a fixed value, takes more than 50 seconds,
Modify the stored procedure, field dac to set dac=sm3 (" ABC "), article 1 million data change at this time took 1 hours and 16 minutes,
Consult a warrior, this how to optimize? Thank you very much!