Postgres is designed to be modified and is highly extensible. Many companies add features or capabilities that are not native to Postgres. Some things you can d

Postgres is designed to be modified and is highly extensible. Many companies add features or capabilities that are not native to Postgres. Some things you can do using extension interfaces (linking in shared libraries) and others require modifying the source. It can get a bit blurry, it really depends on what you are trying to do. It is not that uncommon to mod Postgres to do something it can’t do out of the box. I’ve been paid to do it many times for companies that use Postgres to make it do just a bit more. This is a pretty valuable and unique property of Postgres; it has many fundamental limitations but a lot of small limitations can be coded around if you are handy with C.