Increase transaction query performance

MySQL & MariaDB Other MySQL® Questions
1

Hi,

I am installed My SQL 4.1 database under Red Hat linux with 1GB RAM.

Table A (No Index) having two columns
MobileNo
Name

Table B (No Index) also having the same structure (MobileNo and Name)

Table A having 5,400,000 records.
Table B having 1,200,000 records.

this is query to run

delete A from A,B where A.MobileNo = B.MobileNo

It is taking more than 6 hrs.

I am using default my.cnf file setting.

How to improve the performance to change the my.cnf file?

2

Can you elaborate a little? In particular, are these tables MyISAM or InnoDB? Did you attempt this delete on a system with a heavy transaction load or on a test system? Can you provide the results of SHOW CREATE TABLE for both of these tables? What are the results of:

EXPLAIN SELECT A.* FROM A, B WHERE A.MobileNo = B.MobileNo;