Imagine a library of books. Each book is a record. The library is the
table. A user may check out a book and the shelf space it once occupied
will store the minute that the user checked the book out. Every 5
minutes, a magical librarian walks through the library and when a book
has been checked out
;
> > As a programmer you can see psql source and directly found how SQL
> > query execute this tool. The PostgreSQL needn't non-standard statements
> > like MySQL's SHOW, DESC -- the postgreSQL has system catalogs.
FreeBSD has had some great succes
