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. Another name for a data dictionary view is __________________ or _________________.
Static or dynamic
BETWEEN
Control - Revoke - Define - TRUNCATE Manipulate - MERGE
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.

2. Users can only see changes made to a database once they have been...
VALUES clause of an INSERT statement
FALSE
Committed
Common column value

3. What is the main difference between the NOT EXISTS and the NOT IN operators?
The way NULL values are treated
Retrieve
Twice
Crow's foot

4. To restart a sequence at a lower number - you can drop and ________ the sequence.
IN ANY ALL SOME
RENAME just_two_more_weeks TO finally_i
Re-create
User-defined reports

5. Which format mask displays December 31st - 1999?
Crow's foot
Month ddth - yyyy
Location of the file
All

6. PAGESIZE
Fractional seconds
FALSE
Default is 14; when you use the default - you repeat the heading every 14 rows.
X

7. The NEXTVAL and CURRVAL pseudocolumns can be used in which of the following SQL constructs? Select all that apply.
VALUES clause of an INSERT statement
ANY
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
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.

8. When using the following data: NUMBER(10 -4) - the # 10 is called the __________.
Primary key/foreign key
Precision
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.
BETWEEN

9. What is the keyboard shortcut for the ROLLBACK command?
BETWEEN
Results
RUN SCRIPT
F12

10. When disabling a unique or primary key - you can keep the index if you specify the __________________ clause in the ALTER TABLE statement.
When the table is small (unless your business rules require you too)
Results
KEEP INDEX
Equijoin and identical column names

11. What do views do that makes them so useful for security?
Fractional seconds
@ or START
Hide data
User-defined reports

12. All SQL statements contained within a script must end with a _______________ - even if they are done in SQL Developer.
Fractional seconds
ON
MINUS
Semicolon or forward slash

13. A _________ subquery returns a single column with a single row
Month ddth - yyyy
V$
Scalar
A correct statement

14. Explain the steps needed to run a script in SQL Developer
Location of the file
Same
Command returns the number of records returned by a query.
Load the file into the SQL Statement Box - by opening the location the file is stored and inserting it into the statement Box. Next you can press the F5 key.

15. ___________ subqueries allow you to reference columns from the outer query and execute the inner query repeatedly
Extra spaces
Command returns the number of records returned by a query.
UNION
Correlated

16. The __________ operator is inclusive of the two values specified.
Hide data
VALUES clause of an INSERT statement
KEEP INDEX
BETWEEN

17. What does the following function return? SELECT LENGTH(NULL) - FROM dual
Null
Month ddth - yyyy
COMMIT
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.

18. SELECT * FROM instructor ORDER BY phone
A correct statement
Self-joins
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
Twice

19. What does SQL stand for?
Same
UNION operator
Structured Query Language
ANY

20. FEEDBACK
Data
ADD
Command returns the number of records returned by a query.
Groups

21. Oracle uses the outer join operator to indicate that nulls are shown for...
B-Tree Index
Optional
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.
Non-matching rows

22. The same function can be used ______ in a SELECT statement.
ANSI
INTERSECT
Any
Twice

23. When using the following data: NUMBER(10 -4) - the # 4 is called the __________.
Any
Scale
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
Details

24. When writing an ANSI outer join - the keywords _________ OUTER and _________ OUTER are added to the __________ keyword to indicate the rows from which table to use.
RIGHT LEFT JOIN
Equijoin and identical column names
Same
4

25. List the different types of data dictionary views.
USER_ - ALL_ - DBA_ - and V$
NATURAL JOIN
@ or START
4

26. The focus of the logical data model is _____________
Data
Equijoin
When the table is small (unless your business rules require you too)
Business problems

27. The DUAL table can be used for...
Multiple rows
ANSI
DD-MON-YY
Testing functions

28. Match each of the SQL commands on the left with a verb from the list.
Running a script file
Control - Revoke - Define - TRUNCATE Manipulate - MERGE
Hide data
X

29. Write an SQL statement for SQL *Plus in which you want any unique menu items to be displayed from the restaurant table
SUM
Re-create
SELECT DISTINCT menu FROM restaurant
Testing functions

30. List the steps performed by a correlated subquery.
Multiple rows
BETWEEN
Export Data
**** 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

31. You can pass parameters from the operating system when ___________ in SQl*Plus
Running a script file
@ or START
F12
Logical unit of work

32. _________ and __________ functions are opposites of each other and provide a value in a group of rows.
All
Both MIN and MAX
X
Lists all objects accessible for the chosen database connection. Also lists a helpful dependencies report for accessing change impact.

33. Explain how Oracle treats locks when a database is being updated and needs to be viewed by other users.
All
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
V$
LIKE

34. When writing the syntax for finding information on three or more tables - the parenthesis around the ON clause is...
ADD_MONTHS function
Equijoin and identical column names
Retrieve
Optional

35. ____________ are useful for analyzing and exploring the relationships within your data
Self-joins
Run scripts
BETWEEN
Correlated

36. Instead of using the Oracle Outer Join Operator or the ANSI syntax - you can achieve the same result with two SQL statements: ____________ and a ____________
12:00:00 A.M
Equijoin and correlated subquery
MINUS
Testing functions

37. An outer join includes the result rows returned by an __________ plus extra rows where no matches are found.
Testing functions
Equijoin
SET clause of an UPDATE statement
V$

38. Checks whether any value in the list makes the condition true.
RIGHT LEFT JOIN
Any
BETWEEN
DESC dict;

39. You can __________ DISTINCT and a GROUP BY clause in the same SELECT statement.
Recursive
Another null
COUNT(registration_date) - AVG (capacity) - MIN (capacity) - MAX (capacity)
Combine

40. Self-joins are useful for performing comparisons and checking for ___________ in data.
Inconsistencies
Fractional seconds
Load the file into the SQL Statement Box - by opening the location the file is stored and inserting it into the statement Box. Next you can press the F5 key.
Equijoin and correlated subquery

41. You can simplify the writing of SQL statements by writing SQL _________ that generate and execute other SQL statements.
F12
The way NULL values are treated
Script
@ or START

42. Checks whether any value in the list makes the condition true.
Details
All
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
Any

43. The ______ depicts the M of a 1:M relationship.

44. When returning multiple rows - a subquery must contain the _____ - _____ - _____ - or ______ operator - otherwise Oracle will return an error
Precision
99.99
IN ANY ALL SOME
Groups

45. How many characters can be stored in the CHAR column/field?
Primary key/foreign key
2000
Surrogate key
Black

46. The time zone displacement value indicates the time difference from _______.
Multiple rows
ON
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.
UTC

47. The key that most database designers prefer and is chosen by the system is the _____________ key.
Surrogate
Asterisk
Precision
Black

48. The TIMESTAMP WITH LOCAL TIME ZONE data type allows...
**** 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
ANY
Fractional seconds
X

49. The query retrieves more than 5 to 15 percent of the rows
Command determines the total number of characters SQL *Plus displays in on line before beginning a new line.
Load the file into the SQL Statement Box - by opening the location the file is stored and inserting it into the statement Box. Next you can press the F5 key.
RENAME - COPY - DROP - TRUNCATE - LOCK - & COMMENT
The indexed column is part of an expression. In this case - consider creating a function-based index instead

50. NUMBER functions can be...
Nested
SYSDATE
Mathematical equations
Control - Revoke - Define - TRUNCATE Manipulate - MERGE