Oracle Database 12c: EM Database
Express
Oracle Enterprise Manager Database Express, also referred to as EM Express, is a web-based tool for managing Oracle Database 12c. Built inside the database server, it offers support for basic administrative tasks such as storage and user management, and provides comprehensive solutions for performance diagnostics and tuning..
EM Express
Architecture
EM Express is designed to be lightweight and to incur minimal overhead on the database server. In order to achieve this goal, EM Express is built inside the Oracle Database and only uses internal infrastructure components. . such as XDB and SQL*Net. It does not require any separate middle-tier components.
Since EM Express is built inside the database, the database has to be open in order to use EM Express, and EM Express cannot perform actions outside the database.
EM Express does not have background tasks or processes that periodically collect information. Instead, it utilizes data that is already collected by the database. Data is requested only when the user interacts with the UI and all UI processing is done in the browser, thus minimizing load on the database server.

EM Express introduces two key features:
The Performance Hub provides a consolidated view of
all performance data for a given time range.
The performance data shown includes ASH Analytics,
SQL Monitor, ADDM, as well as metrics that describe
workload characteristics and database resource
usage. For more information, see the section
on Performance Hub
A Composite Active Report is a single HTML file that
embeds a set of correlated active reports, allowing
the user to navigate from one active report to
another without requiring a connection to the
database. Composite Active Reports are a
significant enhancement to the Active Report
technology introduced in Oracle Database 11g.
For more information, see the section on Composite Active Reports.
In order to assist a Database Administrator, EM
Express also provides support for basic
administrative tasks such as storage and user
management. For more information, see the
section on EM Express
Administration Functions.
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Frequently Asked Questions
Answers
How do I log into EM Express?
A user can log into EM Express by using a browser and
opening the URL to https://<hostname>:<port>/em.
A login page will be displayed, and the user can log in with
any valid DB credential.
How can I find the port on
which EM Express is configured?
When dbca completes, it indicates the port on which EM
Express is configured. If that information is no
longer available, there are two ways to find the
HTTP/HTTPS port for EM Express:
> lsnrctl status | grep HTTP
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcps)(HOST=xxx.us.oracle.com)(PORT=5500))(Security=(my_wallet_directory=/u01/oracle/app/oracle/admin/orcl/xdb_wallet))(Presentation=HTTP)(Session=RAW))
or from SQL*Plus:
SQL> select dbms_xdb.getHttpPort() from
dual;
GETHTTPPORT
-----------
8080
SQL> select dbms_xdb_config.getHttpsPort() from dual;
GETHTTPSPORT
------------
5500
How can I give users read-only
access to EM Express?
To grant users read-only access so that they can view the
UI but not make any changes, grant them the
EM_EXPRESS_BASIC role as follows:
SQL> grant EM_EXPRESS_BASIC to
<user>;
Does EM Express have support
for RAC?
Yes. EM Express is a database management tool that
is automatically RAC-aware. When connected to a RAC
system, the information displayed is for the entire
database, i.e. for all instances. For example, the
average active session values is aggregated across all
instances. In addition, an extra Instances tab is
displayed in the Performance Region on the DB Home Page to
show the distribution of average active sessions across
instances.
How can I configure EM Express
on CDB and PDB?
Users can configure EM Express both at the root and the
PDB containers, with each container using a different
HTTP/HTTPS port. When connected to the root
container, the information displayed is for the entire
database including all PDBs. When connected to a
PDB, the information displayed is restricted to data for
the PDB. For more information, see the section on EM Express on CDB.
Do I need any database
privileges to use EM Express?
In order to use EM Express, a database user needs to have
been granted the EM_EXPRESS_BASIC or EM_EXPRESS_ALL
role. The DBA role includes both the
EM_EXPRESS_BASIC and the EM_EXPRESS_ALL roles.
EM_EXPRESS_BASIC grants a user read-only privileges, so
that the user can view pages but not perform any
actions. EM_EXPRESS_ALL grants a user all privileges
required to perform any action in EM Express.
Do I need licenses or packs to
use EM Express?
You can use the basic administration features offered by
EM Express with no additional licenses. However, to
use the performance features, you will need the Oracle
Diagnostics Pack. For the Performance Hub, you will
need the Diagnostics Pack and for the SQL Monitor and SQL
Tuning Advisor features, you will need the Tuning Pack.
Depending on what packs you own, you should set the control_management_pack_access
init.ora parameter on your system. For example, if
you have the Diagnostics Pack, but not the Tuning Pack,
you should set the control_management_pack_access
parameter=DIAGNOSTIC.
Is EM Express supported on Oracle
Database Standard Edition? What about Database XE?
Yes, EM Express is supported on both Standard Edition
(SE) and Express Edition (XE). However, features
that require the Diagnostics and Tuning Packs will not be
available on SE and XE. For example, the Performance
Menu won't be available on SE and XE because the features
require the Diagnostics or Tuning Packs. Similarly,
certain regions of the Home Page, such as the SQL Monitor
List, will not be shown on SE and XE because they require
the Tuning Pack.
When using EM Express on RAC, how can I
see instance-specific information?
Although EM Express is RAC-aware in general, some pages will
allow you to view instance-specific information as
well. There are two ways to get to this
instance-specific information.
The first way is using the Status Region in the Home
Page. You can click the "RAC - <n> instance(s)
up" link and it will take you to a page with the instance
details. You can now select an instance and navigate
to the Performance Hub, the Instance Home Page, or the
Memory Page for the selected instance.
The second way is through the Performance Hub. If you
click the RAC tab, you will see a list of instances.
From this list, you can now select an instance and navigate
to the Performance Hub, the Instance Home Page, or the
Memory Page for the selected instance.
For Undo Details, the information is always
instance-specific. When you navigate to the Undo
Management page using the Storage menu, you are taken to a
page that lists all the instances and the undo summary
information for each instance. You can now select an
instance and navigate to the Undo Details Page for the
selected instance.
EM Express seems slow when using
HTTPS. Why?
Some browsers disable caching if you are using SSL and
have a self-signed certificate. This is known to
occur on Chrome and Safari. To avoid this issue, use
a CA certificate when using HTTPS or use a browser that
supports caching when using self-signed certificates
(Firefox or IE).
Can I run EM Express in Safari?
Yes, you can run EM Express in Safari on MacOS. You
can also run EM Express in Safari 5.0.* on Windows, but
Safari 5.1.* on Windows is known to have an issue with
input text fields that prevents users from entering their
username and password on the login page
What is the recommended screen
resolution for EM Express?
Although the EM Express UI dynamically resizes based on
the screen real-estate available, it works best with
resolutions of at least 1280x1024 or 1600x900.
How do I set up EM Express?
DBCA allows you to set up EM Express at the time of database
creation.
If you want to manually set up EM Express, simply configure
the HTTPS or HTTP port by logging into the database and
setting the port:
SQL> exec
dbms_xdb_config.sethttpsport(5500);
or
SQL> exec dbms_xdb_config.sethttpport(8080);
If you are using a listener TCP port other than 1521, you
will also need to set the dispatchers and local_listener
initialization parameters. Please see the
documentation for further information.
I'm trying to perform a task I used to
do in DB Control. Where is it in EM Express?
Although EM Express provides support for basic
administrative tasks, it is not a direct replacement for
DB Control. As explained in the Architecture
section, EM Express is built inside the database server
and cannot perform actions outside the database.
Also, EM Express is focused primarily on providing
performance management and monitoring functionality, and
is not meant to be an all-around database administration
tool.
Is EM Express secure?
Yes, EM Express uses SSL (HTTPS) out of the box.
Why am I getting a "This Connection is
untrusted" message when I try to log into EM
Express? Is this a security concern?
The browser displays this message if you are using a
self-signed certificate. You can either create an
exception for it, or you can replace the default
wallet/certificate with a trusted certificate. See
the documentation for more information.
How can I replace the default
wallet/certificate?
The XDB wallet is stored in the $ORACLE_BASE/admin/<db_name>/xdb_wallet
directory . If ORACLE_BASE is not defined, the XDB
wallet is stored in $ORACLE_HOME/admin/<db_name>/xdb_wallet,
where <db_name> is the unique database name.
What should I do if the default XDB
wallet expires?
If the wallet expires, you can create a new wallet with
an existing SSL certificate and replace the existing
wallet with the new one. Alternatively, you can use
dbms_xdb.installDefaultWallet() to replace the
existing wallet with a new Oracle wallet that has a
self-signed certificate.
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