[GENERAL] extend sql?

Hello everyone,I want to konw how to extend the SQL. For example,Create table temp [sec_level],sec_level means the secure level of the table that you have created,how to do this? xiapw

[GENERAL] who has some document about extending postgresql

Hi,who has some some document about extending postgresql,can you mail it to me? Sting

[GENERAL] how to add a new column to system table

I wanted to add a new column to system table(pg_database),but failed at last. Who know how to do this and can you tell me ?

[GENERAL] I want to know how to improve the security of postgresql

Hi guys,can you give me some advices about how to improve the security of postgresql? Now I major in the security of postgresql and the destination is create a database with security level of B1(TCSEC),what should I do now,what program language should I use? Thanks! Sting