Thanks to "Laws of Physics", it is possible to SCIENTIFICALLY verify whether PostgreSQL is working as per ISO/ANSI SQL specifications. To validate PostgreSQL, regression test package (src/test/regress) is included in the distribution. Regression test package will verify the standard SQL operations as well as the extensibility capabilities of PostgreSQL. The test package already contains hundreds of SQL test programs.
You should use the computer's high-speed power to validate the PostgreSQL, instead of using human brain power. Computers can carry out software regression tests millions or even billions of times faster than humans can. Modern computers can run billions of SQL tests in a very short time. In the near future the speed of computer will be several zillion times faster than human brain! Hence, it makes sense to use the power of computer to validate the software.
You can add more tests just in case you need to, and can upload to the primary PostgreSQL web site if you feel that it will be useful to others on internet. Regression test package helps build customer confidence and trust in PostgreSQL and facilitates rapid deployment of PostgreSQL on production systems.
Regression test package can be taken as a "VERY SOLID" technical document mutually agreed upon between the developers and end-users. PostgreSQL developers extensively use the regression test package during development period and also before releasing the software to public to ensure good quality.
Capablilities of PostgreSQL are directly reflected by the regression test package. If a functionality, syntax or feature exists in the regression test package then it is supported, and all others which are NOT listed in the package MAY not be supported by PostgreSQL!! You may need to verify those and add it to regression test package.