There are many blogs about the product and so on. I want to recommend that you enable and give your developers access to it. Setting them up and getting them to scale the mountain of complexity that is the normal Enterprise Manager is probably not what you want to do.

However, EM Express is a slimed down version focusing pretty much on just what a developer ought to care about, seeing the processes in the database and data about how they perform. Maybe in production, but probably more useful for most in development environments as that is where they spend their days.

Enabling it is easy enough. If you have Oracle DB XE running it is enabled by default so “http://localhost:5500/em” should bring up the login. For other editions you’d just enable it in the database.

--Check if it is running with
select dbms_xdb_config.gethttpsport from dual;

If the select returns a number like 5500, it is already open and you should be able to point your browser to it. “http://<hostname>:<port>/em”

--If it returns zero, then activate by
exec dbms_xdb_config.set httpsport(5500)    

Now if you are running with multitenant you can use the same port for CDB and all PDBs. Assuming you opened to port in CDB$ROOT, you can set it to also (at least from version 19) allow access to PDBs by allowed accounts.

exec dbms_xdb_config.setglobalportenabled(TRUE);

Now you can enter the PDB-name in the container field on the login to get Enterprise Manager Express focused on a specific PDB.

In addition to this, you need an account hat has access to view it. Any DBA-account will do. However, not every user in the databas has access to one. So you can give users EM_EXPRESS_BASIC or EM_EXPRESS_ALL roles to allow access. _BASIC is pure read only access while _ALL gives full access to all features of EM Express. Both these roles also give SELECT_CATALOG_ROLE.

Do note that some features in EM Express – som would say most – requires additional licenses. So configure what parts of enterprise manager you have licensed in your databases. It is done via the init parameter control_management_pack_access.