A naive wc based “lines of code” for MySQL 5.6 sql/ directory is ~490kLOC which contasts with MySQL 5.5 being ~375kLOC by the same measure. If we diffstat the sql/ directory like I did for MariaDB 5.5 we get:
357 files changed, 172871 insertions(+), 67922 deletions(-)
Versus, as you remember from yesterday for MariaDB 5.5 over MySQL 5.5:
250 files changed, 83639 insertions(+), 23090 deletions(-)
The MySQL 5.5 to 5.6 sql/ changes line up with What I found in my post MySQL modularity, are we there yet? in that the core server code for MySQL has grown by about 100,000 lines of code.
The jump from MySQL 5.5 to MariaDB 5.5 is a smaller one than jumping from MySQL 5.5 to MySQL 5.6, at least in terms of changed server code.
A judgement all on if a smaller diff is a safer jump or not will rest more with the quality of that code more than anything else. As we’ve seen previously, modularity isn’t coming to the MySQL code base any time soon.