Shenkaoziliao:
This series of blog mainly Cenkaoziliao have CUUG database Rannai Gang teacher teaching notes, "SQL optimization core idea" (Luobing Sen, Huang Chao Zhong Jiao with), "PostgreSQL Inside: query optimization Depth" (Zhang Shujie a), ranking in no particular order.
Oracle maintains a lot of dynamic performance view, we can identify some performance issues in accordance with these views, such as V $ SQL, V $ SQLAREA, etc., we can find out the executed SQL execution plan, you can do some SQL scripts to find data SQL performance problems, yo teacher masterpiece "SQL optimization core idea" there are many excellent online and SQL scripts, you can look yourself.
These dynamic performance views and great God-written script performance is extremely useful for developers of high-level language, because developers sometimes do not have permission or no chance to get AWR performance reports, etc., only to see performance issues based on the dynamic performance views.