On Apr 24, 2017, at 8:14 AM, Federico Razzoli <federico_raz@yahoo.it> wrote:
Hi Jocelyn,
The article you linked is quite old, so I wanted to check the source code to find if something changed. I didn't investigate much but I searched in MariaDB's master branch via GitHub. The search strings were 'read_rnd_buffer_size' and 'read-rnd-buffer-size'. I found nothing except for some test files and the variable initialization at server startup. I repeated the same searches in MySQL master branch, and again, I found only tests and initialization. Can you explain this? The variable is unused now?
One use of read_rnd_buffer_size was with mrr in MySQL. After the changeover to Mariadb, we missed that Mariadb uses mrr_buffer_size instead of read_rnd_buffer_size. You probably know that, but, just pointing out one place where it would have been removed from the code. Steve