http://sqlserverpedia.com/wiki/Understanding_the_StackOverflow_Database_Schema Notes about schema used by StackOverflow.com and related websites. It is very simple, only several tables used. (most likely because there are performance problems with joins)
http://translate.google.com/translate?u=http%3A%2F%2Fplakhov.livejournal.com%2F144249.html%3Fthread%3D2563193%23t2563193&sl=ru&tl=en&hl=&ie=UTF-8 Google translate of 2 posts in Russian section of LJ about route costs look up problem commonly faced by telephony operators
http://recursion.com/interpolique.html in 3 lines Dan’s method is:
http://sql.ru/forum/actualthread.aspx?tid=754989 Some comments on modeling friendlits user activity, for social media websites (or apps)
http://www.greensql.net/ SQL-proxy/filtering software for MySQL and PostgreSQL databases, used to prevent SQL-injection-like attacks, filter-out dangerous SQL, etc
http://m.habrahabr.ru/post/30046/ PostgresSQL: how to count number of rows returned by a query and do it fast
http://www.randombugs.com/linux/mysql-postgresql-benchmarks.html yet another mysql vs postgresql benchmark using “OSDB”. Small difference between the two, but consider that benchmark was done on 2-way SMP, 3GB ram, 1 SATA DISK and a small dataset.
http://www.mysqlperformanceblog.com/2006/08/09/cache-performance-comparison/ gives you an idea how different caching methods perform. Read it before implementing something
http://sql.ru/forum/actualthread.aspx?tid=606215&pg=3 example: REVOKE SELECT ON pg_catalog.pg_proc, information_schema.routines FROM public
http://sql.ru/forum/actualthread.aspx?bid=36&tid=552763&pg=2 design pattern for friends/users, i.e. how to organize user-friend relationship. patters suggest that you need to make 2 tables, i.e freindship and friendship:user