List of differences between SQL databases

Question

Most SQL databases follow the ANSI SQL standards to a degree, but

1. The standard is ambiguous, leaving some areas open to interpretation (eg: how different operations with NULLs should be handled is ambiguous)

2. Some vendors contradict the standard outright or just lack functionality defined by the standard (eg: MySQL has a list of differences between the standard and their implementation)

3. Some databases will behave differently depending on how they are configured, but configuration can be changed to have them behave the same way (eg: Oracle performs case-sensitive string comparisons by default, while SQL Server does them case-insensitve)

4. There is some functionality that is not part of the standard but is implemented by different RDBMSs anyway, albeit with different names (eg: Oracle's LISTAGG = MySQL's GROUP_CONCAT)

Is there a resource with a comprehensive list of quirks and gotchas to pay attention to when you are trying to write something that is supposed to be compatible with multiple databases?

Answer 1

I'm not sure how comprehensive this list is, but maybe this will help - http://troels.arvin.dk/db/rdbms/

Answer 2

Except of already mentioned some comparison you can find in Wikipedia

Also similar question was already posted on Stackoverflow where you can fin a couple of useful links.