Recently I took a peak at a default mysql installation and found one interesting, to not say scary, thing. SQL_MODE comes set to empty string and if you dig into the documentation you find that... you find nothing! Yes you heard me, whatever a blank SQL_MODE means is not known yet is what most of the people run with because this little fact is advertised nowhere, especially not in the post installation guidelines. more »

To be compatible across different backends the best option is to store ips and netmasks as longint and manage the transformations in code, otherwise, if compatibility is not a concern or writing that code is a problem, both mysql and postresql offer their own built-in functions to aid with the job. more »