Practice set for DBA Lecture 3. Read the full lesson first: SQL*Plus Explained: The DBA’s Command-Line Tool on eLecturesAI.
Reading a topic and knowing a topic are two different things. The quickest way to find out which one you have is to answer questions without looking at your notes.
This page has 20 MCQs, 5 short questions and a score guide, all based on DBA Lecture 3: what SQL*Plus is, connecting, handy commands, the data dictionary and SPOOL.
- Click the option you think is correct. It turns green if you are right and red if you are wrong.
- Read the explanation that opens under the question.
- If you got it wrong, use the Revise link to go back to that exact part of the lesson.
- Check your score at the end and follow the guide.
Section 1: About the tool
Q1SQL*Plus is best described as:
Show answer
Answer: B. SQL*Plus is a client tool. You type commands, it sends them to the database and shows the answers in the same text window.
Revise: What is SQL*Plus?
Q2Why can SQL*Plus be used even on a server that has no graphical screen?
Show answer
Answer: C. It needs only a text window, so it works wherever you can get a command prompt, including servers installed without a desktop.
Revise: What is SQL*Plus?
Q3Which of these is NOT a reason DBAs like SQL*Plus?
Show answer
Answer: D. SQL*Plus is a simple text tool. It does not draw charts. Its strengths are that it runs anywhere, it is scriptable and it always comes with Oracle.
Revise: What is SQL*Plus?
Section 2: Connecting to the database
Q4Which is the correct way to start SQL*Plus and connect from the command prompt?
Show answer
Answer: B. The pattern is sqlplus user@service. SQL*Plus then asks for the password.
Revise: Connecting to the database
Q5You are already inside SQL*Plus and want to switch to a different user. Which command do you use?
Show answer
Answer: C. CONNECT username@service switches you to another user. It asks for the password, then prints “Connected.”
Revise: Connecting to the database
Q6Which command tells you which user you are currently connected as?
Show answer
Answer: A. SHOW USER always tells you who you are. The other three are not SQL*Plus commands for this job.
Revise: Connecting to the database
Q7After you run SHOW USER, SQL*Plus prints USER is "SYSTEM". What does this tell you?
Show answer
Answer: D. The text in quotes is the name of the user you are connected as. Here, that is SYSTEM, an administrator account.
Revise: Connecting to the database
Q8Why should you avoid working as an administrator when a normal user is enough?
Show answer
Answer: B. The same typing mistake is much more dangerous with powerful rights. Use the administrator account only for jobs that really need it.
Revise: Connecting to the database
Section 3: Handy SQL*Plus commands
Q9SQL*Plus keeps your last SQL command in memory. This place is called:
Show answer
Answer: C. The buffer holds your last SQL command. The commands L, / and ED all work on it.
Revise: Handy SQL*Plus commands
Q10What does the / command do at the SQL> prompt?
Show answer
Answer: A. / runs the command that is in the buffer again. L shows it, ED edits it and CLEAR SCREEN clears the window.
Revise: Handy SQL*Plus commands
Q11You made a typing mistake in a long SQL command. What is the best way to fix it?
Show answer
Answer: D. ED opens the last command in a text editor. Fix it, save, close, then type / to run it. This is much faster than retyping.
Revise: Handy SQL*Plus commands
Q12What does the L command do?
Show answer
Answer: B. L stands for LIST. It shows the SQL command currently in the buffer.
Revise: Handy SQL*Plus commands
Q13What does SET PAGESIZE 50 control?
Show answer
Answer: C. It sets how many lines SQL*Plus shows on a page before it repeats the column headings. A larger value keeps long reports cleaner.
Revise: Handy SQL*Plus commands
Section 4: The data dictionary
Q14What is the data dictionary in Oracle?
Show answer
Answer: D. The data dictionary holds information about the database: its users, tables and settings. Think of it as the notice board of a building.
Revise: Ask the database about itself
Q15Which statement shows the Oracle version?
Show answer
Answer: A. The banner column of v$version holds the version text. The other statements use the wrong view or the wrong column.
Revise: Ask the database about itself
Q16Which statement lists the tables that you own?
Show answer
Answer: B. USER_ views show what you own, so user_tables lists your tables. If it says “no rows selected”, you simply do not own any tables yet.
Revise: Ask the database about itself
Q17The data dictionary views are read-only windows into the database. What should a DBA do with them?
Show answer
Answer: C. Reading with SELECT is safe. Oracle keeps the dictionary up to date by itself, so you never edit it by hand.
Revise: Ask the database about itself
Section 5: Saving output with SPOOL
Q18What does the SPOOL command do?
Show answer
Answer: A. SPOOL file starts copying the screen output into a file. DBAs use it for reports and to keep a record of what they did.
Revise: Save output with SPOOL
Q19Which command stops spooling and closes the file?
Show answer
Answer: D. Only SPOOL OFF closes the file. Note that SPOOL END or SPOOL STOP would just start a new spool file with that name.
Revise: Save output with SPOOL
Q20Which sequence correctly saves the result of a query into a file?
Show answer
Answer: C. Start the spool first, run the query while it is on, then close it with SPOOL OFF. In the other options the query runs when no file is open.
Revise: Save output with SPOOL
Short questions (write the answers in your own words)
Don’t just read these. Write each answer on paper in 2-3 lines, then compare.
S1. Give three reasons why DBAs like SQL*Plus.
Show model answer
It runs anywhere because it needs only a text window, so it works even on servers with no graphical screen. It is scriptable, so the same commands run the same way every time. And it is always available because it comes installed with Oracle.
S2. Explain what L, / and ED do, and when you would use each.
Show model answer
All three work on the last SQL command, which SQL*Plus keeps in the buffer. L lists it so you can see it. / runs it again. ED opens it in a text editor so you can fix it without retyping. Use L to check, ED after a typing mistake, and / to run it again after fixing it.
S3. What is the data dictionary? Write two queries that read from it.
Show model answer
It is Oracle’s set of built-in tables and views that describe the database itself, such as its users and tables. It is read-only, so a DBA reads it with SELECT. Examples: SELECT username FROM all_users; lists the users, and SELECT table_name FROM user_tables; lists the tables you own.
S4. Write the SQL*Plus lines that save the list of users into the file C:\labs\users_report.txt.
Show model answer
SPOOL C:\labs\users_report.txt, then SELECT username FROM all_users;, then SPOOL OFF. The spool is started before the query and closed after it.
S5. You typed SELECT usrname FROM all_users; and got an error. Describe how to fix and run it without retyping.
Show model answer
Type L to see the command in the buffer, then ED to open it in the editor. Change usrname to username, save the file and close the editor. Back at the prompt, type / to run the corrected command.
Check your score
Count your correct MCQs (out of 20):
| Score | What it means | What to do next |
|---|---|---|
| 18 – 20 | Excellent. The concepts are solid. | Move on to the next lecture. |
| 14 – 17 | Good, with a few gaps. | Re-read only the sections linked under the questions you missed. |
| 10 – 13 | Half-way there. | Read the lesson again slowly, then retry this quiz tomorrow. |
| Below 10 | The basics are not settled yet. | Read the full lesson once more, type the commands yourself in SQL*Plus, then retake the quiz. |
Go back to the full lesson: SQL*Plus Explained →
SPOOL OFF. The other is mixing up L (show the command), / (run it) and ED (edit it). Say each one in your own words before the exam.Frequently asked questions
Are these MCQs enough for the exam?
They cover the whole of Lecture 3, but real exams also ask you to write short answers and commands. Practice the five short questions above as well.
What is the best way to use an MCQ quiz?
Answer first, check later. Reading the answer without trying the question gives a false feeling of knowing it.
Where do I learn the topic if I got most answers wrong?
Start with the lesson on eLecturesAI: SQL*Plus Explained: The DBA’s Command-Line Tool. Each question above also links to the exact section to revise.
Written by Engnr.Dr. Muhammad Tahir Dlbar
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