Oracle Apex Interview Questions

Oracle Apex Interview Questions

Q.1) What is Application Express?

Ans) It is formerly called HTML-DB, a web-based RAD tool which resides in Oracle database. Using browser based user interface and limited programming experience, you can build a complete data-centric web application in a very fast development cycle.

From the end user’s perspective, the deployed applications require only a browser and access to an Oracle database running Application Express.

Q.2) What are the uses of APEX?

Ans)

-Builds professional looking web applications that are both fast and secure.

-Runs on and lives in Oracle database. APEX framework and meta data are stored in Oracle tables.

-It is FREE. No licensing required.

-Fast learning curve for developers to build application.

-Deployment of application is as simple as 'Export and Import' if hard coded references of values that change between environments are avoided.

-Lot of scope for customization of application look and feel.

-Scalable for high user volume. AskTom, former Oracle Metalink (before migrated to Flash version) and many applications are built using APEX.

-Can be configured to use Oracle SSO and EBS fnd user repository.

Q.3) Who uses APEX?

Ans) If you are running on oracle database and you want to build rich web application with reports, forms, charts, drill downs and dashboards with limited Java experienced developers in a short time frame, Oracle APEX is the most likely candidate for consideration.

Q.4) How APEX Architecture works?

Ans) PEX is installed on Oracle database (above 9.2 version), starting from Oracle 11g it comes pre-installed with the database. It is comprised of meta data in tables, pl/sql code and extensive JavaScript APIs.

The URL request from the browser is translated into appropriate APEX PL/SQL call by either Oracle HTTP Server (Apache) with mod_plsql plugin or Embedded PL/SQL Gateway. This varies by the type of APEX installation on Oracle database. After the data is processed, results are relayed back to the browser as HTML. This cycle happens each time user request or to submit a page. The application session state is maintained in database tables.

APEX installation can be done in two ways. DBAs are more concerned about it than developers. But this determines how the URL is translated.

Oracle HTTP Server: In this three-tier configuration, mod_plsql in Oracle HTTP Server acts a broker between client web browser and server database.

For each URL that is processed, mod_plsql either uses a database session from its connection pool, or creates a new session on the fly and pools it. For mod_plsql to invoke the appropriate database PL/SQL procedure in a URL-processing session, you must first configure a virtual path and associate that path with a Database Access Descriptor (DAD).

A DAD is a named set of configuration values that specify the information necessary to create a session for a specific database and a specific database user/password. This includes the database service name and the Globalization Support setting (for example, language) for the session.

Embedded PL/SQL Gateway: This is a classic client-server architecture where embedded PL/SQL gateway provides the Oracle database with a Web server and also the necessary infrastructure to create dynamic applications. The embedded PL/SQL gateway runs in the XML DB HTTP server in the Oracle database and includes the core features of mod_plsql, but does not require the Oracle HTTP Server powered by Apache.

Oracle HTTP Server is known and proven technology, it has been used for Self Service applications.

Q.5) What kind of activities have you done for apex as apex dba?

Ans) -setup of apex environment.

-SSL configuration.

-USER access.

-security modal definition.

-ad hoc issue and resolution

- patching /Performance /

Inclined to build a profession as Oracle Apex Developer? Then here is the blog post on
 Oracle Apex Training Program.

Q.6) Which platforms are supported by Oracle Application Express?

Ans) Oracle Apex works on the following operating systems:

-Linux x86

-Mac OS X Server

-Linux on Power

-Linux x86-64

-z/Linux

-Linux Itanium

-Solaris x86

-Solaris Operating System (SPARC) (64 bit)

-Microsoft Windows (32 -bit)

-Microsoft Windows (64 -bit Itanium)

-Microsoft Windows (x64)

-AIX5L

-HP-UX PA -RISC

-HP Tru64 UNIX (Compaq / DEC)

-HP-UX Itanium

Q.7) Does APEX works with non-Oracle databases?

Ans) No.

Q.8) What is the current version available?

Ans) APEX 4.2 is released a couple of weeks back.

Q.9) What are skills required for APEX Developers?

Ans) SQL, PL/SQL are essential. HTML, CSS and JavaScript are good to have skills to understand and customize look and feel (themes, templates, .... ).

Q.10) Where to learn and get hands-on APEX?

Ans)There is multitude of sites dedicated to APEX. apex.oracle.com allows anyone to request for free APEX account to build applications or run packaged applications.

Follow the below steps for creating account in apex.oracle.com

-Go to apex.oracle.com and click 'sign up for account' link below Login button.

-Fill administrator information. This user will have all rights to create new users and manage their accounts.

-Enter workspace name (For Ex: XX-APEX). Workspace is dedicated area where you develop applications. A workspace is attached to one or more database schemas. In a typical development environment, you might create a single workspace for all your developers to share.

-Enter the name of database schema and its space allocation.

-Fill justification and complete by confirming the request.

-You will get an email once the request is approved. Oracle administrator do a great job to approve your request as soon as they can. (Usually few hours ... latest a day).

-After clicking on approval link, you get another email with userid/password.

-Then you are set on login on apex.oracle.com  and run sample application under Application Builder.

Q.11) How will you direct your application to use https instead of http?

Ans)-create wallet from apache home (wallet should be in ready state)

-configure ssl.conf file

-restart apache

-verify with opmnctl status -l

 Learn more about Oracle Apex Tutorials in this blog post.

Q.12) What is the current version of APEX and why should I upgrade?

Ans) Beta version APEX 4.2 is released a couple of weeks back. This new version offers many enhancements. Among the most useful are:

Print to PDF

– Users can chose to export their reports and screens to PDF output.

Migrate from MS-Access

– Using an export tool and the Access Migration Workbench, you can migrate user applications to APEX.

Calendar Widget

– Older versions included a calendar widget but now users can choose between day, week, or month calendars.

Improved Page and Region Caches

– Caching improves performance.

Application Builder Defaults

– The developer can set defaults for wizards to reduce development time (basically themes for development).The benefits of upgrading include performance enhancements and additional usability features for both the developer and the end user.

Oracle Database 10g Express Edition only supports Oracle APEX version 2.2.

Q.13) How will you enable SSO for apex application ?

Ans) Login to APEX_030200

Q.14) What are the different type of apex users?

Ans) Users are divided into three types

-primary roles developer ,

-Workspace administrators

-Instance administrators

Q.15) How will you direct your application to use https instead of http?

Ans) -Create wallet from apache home (wallet should be in ready state)

-configure ssl.conf file

-restart apache

-verify with opmnctl status -l

Q.16) What is current version available?

Ans) beta version APEX 4.2

Q.17) Name the file where we configure oracle connection ?

Ans) dad.conf (database access descriptor (DAD))

Q.18) How will you enable SSO for apex application ?

Ans) Login to APEX_030200

@loadsdk.sql;

@regapp.sql;

Q.19) By which user we connect to apex application?

Ans) apex_public_user

Q.20) Which tool you use for publishing reports ?

Ans) BI publisher

Q.21) What kind of activities you have done for apex as apex dba?

Ans) -setup of apex environment .

-SSL configuration

-USER access

-security modal definition

-ad hoc issue and resolution

-patching /Performance /

Q.22) Which scripts  need for registration process for SSO?

Ans) regapps.sql