Test your basic knowledge |

Oracle SQL

Instructions:

Answer 50 questions in 15 minutes.
If you are not ready to take this test, you can study here.
Match each statement with the correct term.
Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.

This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.

1. What is the data type you can use if you need an unlimited number of textual characters?
Multiple rows
Implicit conversion
CLOB
Run scripts

2. You can simplify the writing of SQL statements by writing SQL _________ that generate and execute other SQL statements.
Script
Semicolon or forward slash
The way NULL values are treated
Hide data

3. The __________ operator is inclusive of the two values specified.
BETWEEN
When you want to run the same script repeatedly - but want to be able to change a variable you would use a substitution variable. During the execution of the script the user will be prompted to input the variable to use.
Surrogate
The way NULL values are treated

4. The query retrieves more than 5 to 15 percent of the rows
Constraints are used to enforce the business rules of a system. For instance - 'The salary of an employee may not be a negative number' may be enforced with a check constraint on the salary column. Constraints also ensure integrity and data consisten
Lists all objects accessible for the chosen database connection. Also lists a helpful dependencies report for accessing change impact.
VALUES
The indexed column is part of an expression. In this case - consider creating a function-based index instead

5. The using clause of the ANSI join syntax always assumes an...
CLOB
Equijoin and identical column names
COMMIT
Time zone

6. What is the name of the view where you can find the collection of static and data dictionary tables and views - along with their descriptions?
DICTIONARY
F12
Precision
ON

7. Another name for a data dictionary view is __________________ or _________________.
The SPOOL command - together with a file name - spools any subsequently issued SQL Plus or SQL command to a file. Just as with other file names - you can add a path to store the file in a directory other than your SQL Plus default directory. SQL Deve
Static or dynamic
Precision
Black

8. To place a line comment in your SQL statements - you first place a // at the beginning of the line.
COUNT(registration_date) - AVG (capacity) - MIN (capacity) - MAX (capacity)
Subqueries allow you to nest multiple queries into each other. This gives you the ability to use one statement to break down a problem into individual components. Without nesting queries - you would be required to have multiple queries which could be
TO_CHAR function
FALSE

9. Converting a text literal to DATE format requires the use of the...
Dynamic SQL is used to be continuously updated by the background processes in the Oracle instance but never by the user.
Rounded edges
ADD
TO_CHAR function

10. Checks whether any value in the list makes the condition true.
VALUES
Any
DICTIONARY
KEEP INDEX

11. The ________________ is a type of statement whereby you retrieve data that exists in one table - but not in another.
Leading-edge
Self-joins
Hide data
MINUS

12. __________________ inserts the current date and time.
Actual column
TO_CHAR function
STORAGE
SYSDATE

13. When column names on the tables are different - you use the ______ condition.
X
F12
ON
ANY

14. When you have issued a DELETE command - you can still ________ those rows and restore the information.
Implicit conversion
Committed
SELECT SYSDATE+1/96 - FROM dual
Retrieve

15. Explain how the SPOOL command is used and what program it can be used in.
Self-joins
The SPOOL command - together with a file name - spools any subsequently issued SQL Plus or SQL command to a file. Just as with other file names - you can add a path to store the file in a directory other than your SQL Plus default directory. SQL Deve
Rounded edges
Static or dynamic

16. Write the syntax to rename index just_two_more_weeks_i to finally_i
DICT_COLUMNS
RENAME just_two_more_weeks TO finally_i
X
Asterisk

17. Explain what a static data dictionary view is and how it is used
DD-MON-YY
The static data dictionary stores details about database objects - such as tables - indexes - and views. Whenever a new object is added or an object is changed - data about the object is recorded in the data dictionary.
Leading-edge
Command determines the total number of characters SQL *Plus displays in on line before beginning a new line.

18. What is the syntax used to indicate that you are using the Oracle Outer Join operator?
Asterisk
NATURAL JOIN
ROLLBACK
+

19. Dynamic views begin with a ___________.
V$
Export Data
Location of the file
Constraints are used to enforce the business rules of a system. For instance - 'The salary of an employee may not be a negative number' may be enforced with a check constraint on the salary column. Constraints also ensure integrity and data consisten

20. The _______ operator determines common rows.
DICTIONARY
INTERSECT
Primary key/foreign key
Extra spaces

21. All SQL statements contained within a script must end with a _______________ - even if they are done in SQL Developer.
Recursive
SELECT DISTINCT menu FROM restaurant
DICT_COLUMNS
Semicolon or forward slash

22. What do views do that makes them so useful for security?
Hide data
Equijoin and identical column names
Leading-edge
To achieve good performance for data retrieval and data manipulation statements Oracle uses indexes. In the same way you would use an index in the back of a book to quickly find information - Oracle uses indexes to speed up data retrieval. If the app

23. Self-joins are useful for performing comparisons and checking for ___________ in data.
The SPOOL command - together with a file name - spools any subsequently issued SQL Plus or SQL command to a file. Just as with other file names - you can add a path to store the file in a directory other than your SQL Plus default directory. SQL Deve
Equijoin and correlated subquery
Inconsistencies
Extra spaces

24. Checks whether any value in the list makes the condition true.
All
Any
DECODE
Results

25. Write an SQL statement for SQL *Plus in which you want any unique menu items to be displayed from the restaurant table
Columns
INTERSECT
SELECT DISTINCT menu FROM restaurant
ADD

26. What is the first column of a composite index called?
Extra spaces
Scale
Running a script file
Leading-edge

27. SQL Developer provides an extensive list of useful reports and offers the capability to create your own...
SYSDATE
User-defined reports
Groups
ADD_MONTHS function

28. When is it not a good idea to use an index?
12:00:00 A.M
X
When the table is small (unless your business rules require you too)
Command determines the total number of characters SQL *Plus displays in on line before beginning a new line.

29. A join across three tables can be expressed with the ________ join syntax.
Lists all objects accessible for the chosen database connection. Also lists a helpful dependencies report for accessing change impact.
Recursive
Control - Revoke - Define - TRUNCATE Manipulate - MERGE
ANSI

30. The COUNT function is useful for determining whether a table has...
Details
Data
Self-joins
DD-MON-YY

31. A _________ subquery returns a single column with a single row
Scalar
Rounded edges
SET clause of an UPDATE statement
Retrieve

32. ___________ subqueries allow you to reference columns from the outer query and execute the inner query repeatedly
CLOB
Correlated
A correct statement
SET clause of an UPDATE statement

33. Subqueries can return...
Actual column
Multiple rows
Orable's flashback query feature allows you to look at values of a query at a specific time in the past - such as before specfic DML statements occured. This can be usefull in case a suer accidentally performs an unintended but committed DML change.
CLOB

34. Explain how Oracle treats locks when a database is being updated and needs to be viewed by other users.
When you issue a INSERT - UPDATE - DELETE - or MERGE statement - Oracle automatically locks the modified rows. The lock prevents other sessions from making changes to these rows. The lock is released when the session initiating change commits or roll
**** Select a row from the outer query - Determine the value of the correlated column - Execute the inner query for each record of the outer query. - Feed the results of the inner query to the outer query and evaluate it. It if satisfies the criteria
Run scripts
Lists all objects accessible for the chosen database connection. Also lists a helpful dependencies report for accessing change impact.

35. The _______ function adds values together for a group of rows.
Details
SUM
Combine
Same

36. When returning multiple rows - a subquery must contain the _____ - _____ - _____ - or ______ operator - otherwise Oracle will return an error
IN ANY ALL SOME
X
The main components of a ROWID are the data object number - the number of the data block - the numbers of rows within the data block - and the data file number.
Semicolon or forward slash

37. You can use the ________________ to subtract months from a given date.
ADD_MONTHS function
Lists all objects accessible for the chosen database connection. Also lists a helpful dependencies report for accessing change impact.
RUN SCRIPT
The indexed column is part of an expression. In this case - consider creating a function-based index instead

38. Write a statement that drops the index need_to_pass_i
DROP INDEX need_to_pass_i
Rounded edges
4
999999.9999

39. When disabling a unique or primary key - you can keep the index if you specify the __________________ clause in the ALTER TABLE statement.
LIKE
FALSE
Committed
KEEP INDEX

40. The ALTER SESSION statement can change the session's...
X
Time zone
Fractional seconds
SELECT DISTINCT menu FROM restaurant

41. The time zone displacement value indicates the time difference from _______.
Scale
UTC
Precision
Non-matching rows

42. FEEDBACK
Results
LIKE
Command returns the number of records returned by a query.
FALSE

43. What is the main difference between the NOT EXISTS and the NOT IN operators?
LENGTH
ROLLBACK
Crow's foot
The way NULL values are treated

44. When writing the syntax for finding information on three or more tables - the parenthesis around the ON clause is...
Correlated
@ or START
Optional
Location of the file

45. The ROWID pseudocolumn is not an ________- but it acts like one.
Columns
INTERSECT
Actual column
Location of the file

46. Users can only see changes made to a database once they have been...
SELECT SYSDATE+1/96 - FROM dual
Committed
LIKE
ANSI

47. The COUNT function uses the __________ wildcard.
Asterisk
Groups
ANSI
Subqueries allow you to nest multiple queries into each other. This gives you the ability to use one statement to break down a problem into individual components. Without nesting queries - you would be required to have multiple queries which could be

48. The _______ function lets you perform if-then-else functionality with the SQL language.
Equijoin
DECODE
KEEP INDEX
999999.9999

49. Write a statement for SQL*Plus that shows the dictionary.
Scale
RENAME just_two_more_weeks TO finally_i
Twice
DESC dict;

50. What is Oracle's most popular index storage structure?
ADD_MONTHS function
CLOB
B-Tree Index
Static or dynamic