Redis is a small, fast, special-purpose database. SQLite is similar, with a standard SQL front end. MySQL and Postgres are both large, very mature database servers. How big are these very different codebases?
Redis is probably smaller than MySQL/Postgres, but how do the latter two compare? SQL is tricky to parse, so SQLite is probably in between Redis and MySQL/Postgres.
$ ./manage.py show sqlite redis mysql-5.5 postgresql-9.3
project symbols max avg total
sqlite 1,780 810 19 35,522
redis 3,850 417 16 62,503
mysql-5.5 12,664 1418 23 299,741
postgresql-9.3 29,078 22561 25 742,766
Redis is unsurprisingly small, at 63 KLOC. Oddly, MySQL is less than half the size of Postgres.
SQLite is half the size of Redis, despite needing to parse complex SQL statements. Startling.
