At my previous employer, a small (back then, 10x larger today) outourcing company, I saved a customer's project by increasing innodb_buffer_pool_size from 8MB t

At my previous employer, a small (back then, 10x larger today) outourcing company, I saved a customer's project by increasing innodb_buffer_pool_size from 8MB to 2GB. As a context, it was back in 2010 when MySQL had MyISAM as the default storage engine and I think 99% of the tutorials on tuning MySQL's performance were focused on MyISAM, while the customer had most of its tables as innodb. As a bonus, the value for innodb_buffer_pool_size was expressed in bytes, showing a large, 7 digits, number. Before my arrival there all the senior devs tried to improve the performance of that db. The customer bought a server with 8GB of RAM and dedicated it solely to the db, while the db was about 4GB in size. It was useless. When traffic to the web app increased, the db daemon started paginating and the server load increased to a point of 0 responsiveness. There were simple queries on indexed fields in tables with less than 1k records which took 8 seconds to execute. It took me about 2 weeks of internet scavenging to find the culprit, which was just the innodb_buffer_pool_size size. That was my first commercial project I worked on for the employer and it got me the reputation of THE db performance tunning expert in the company. I was with them for 5 years and that was a quick&easy way to position myself as a valuable team member.