As few properties here at Yahoo! started using MySQL 5.1, its time for me to dig into the performance comparison between 4.1 and 5.1; as a company wide we are skipping the MySQL 5.0 in the middle and going directly to 5.1
I already wrote few test scripts to compare the core features performance along with few tweaks.. test results and tests will be updated here once I have everything in place. I also started looking into comparing memcached vs ydbm (yahoo internal cache system) and more later.