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. UNION ALL does not sort - therefore it is less time consuming to use than the...
Twice
DESC dict;
UNION operator
12:00:00 A.M

2. A _____ is a query definition stored in the database that looks just like a table - but does not have any physical rows
Scale
USER_ - ALL_ - DBA_ - and V$
FALSE
X

3. In a view you can give a column a different name than it has in the...
Has not changed the name
SELECT SYSDATE+1/96 - FROM dual
ADD_MONTHS function
Parent table

4. List the reasons that a subquery could not be unnested.
Parent table
Equijoin
NATURAL JOIN
X

5. The ROWID pseudocolumn is not an ________- but it acts like one.
LIKE
Actual column
Parent table
Any

6. In SQL Developer field names and table names are shown in the color _______.
NATURAL JOIN
Same
ANY
Black

7. When writing the syntax for finding information on three or more tables - the parenthesis around the ON clause is...
Lists all objects accessible for the chosen database connection. Also lists a helpful dependencies report for accessing change impact.
UTC
X
Optional

8. The _______ operator determines common rows.
INTERSECT
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.
RENAME just_two_more_weeks TO finally_i
KEEP INDEX

9. Explain how you can optimize your queries with subqueries and the main advantage of doing so.
Equijoin and identical column names
X
**** 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
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

10. Explain how Substitution Variables are used when writing scripts.
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.
Fractional seconds
Extra spaces
Surrogate key

11. Queries that are found in parentheses are done first - just as in the order of operations when doing...
Mathematical equations
A correct statement
When the table is small (unless your business rules require you too)
Fractional seconds

12. What is the Oracle data dictionary called that contains a set of tables and views containing the data about the database?
Combine
When the table is small (unless your business rules require you too)
ALL_OBJECTS
Results

13. The NEXTVAL and CURRVAL pseudocolumns can be used in which of the following SQL constructs? Select all that apply.
LENGTH
Both MIN and MAX
VALUES clause of an INSERT statement
ADD_MONTHS function

14. How many characters can you have using the VARCHAR data type?
4000
UTC
ON
Leading-edge

15. When using the following data: NUMBER(10 -4) - the lowest number you can possibly have is __________.
999999.9999
IN ANY ALL SOME
Black
Testing functions

16. The RTRIM function is useful for eliminating ________ in a string.
Extra spaces
Parent table
Committed
Rounded edges

17. Information that is returned after you run your statement are found in the __________ tab in SQL Developer.
Month ddth - yyyy
Results
ALL_OBJECTS
Another null

18. Explain the differences in how an ANSI Full Outer Join and a Full Outer Join using the UNION Operator work
X
LENGTH
ADD
COUNT(registration_date) - AVG (capacity) - MIN (capacity) - MAX (capacity)

19. Explain what is found in the All Objects report folder in SQL Developer
12:00:00 A.M
Black
IN ANY ALL SOME
Lists all objects accessible for the chosen database connection. Also lists a helpful dependencies report for accessing change impact.

20. To revert back to a state that happened before you ran your change statement - you issue a ____________ command.
ROLLBACK
Committed
Location of the file
COMMIT

21. SQL Developer provides an extensive list of useful reports and offers the capability to create your own...
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
Surrogate key
User-defined reports
Orphan

22. What is the first column of a composite index called?
SELECT SYSDATE+1/96 - FROM dual
Nested
Leading-edge
Running a script file

23. The purpose of the HAVING clause is to eliminate___________.
**** 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
UTC
Groups
IN ANY ALL SOME

24. Explain how Oracle treats locks when a database is being updated and needs to be viewed by other users.
Equijoin and identical column names
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
Command determines the total number of characters SQL *Plus displays in on line before beginning a new line.
Time zone

25. The __________ operator is inclusive of the two values specified.
Data
Details
BETWEEN
Optional

26. PAGESIZE
SELECT SYSDATE+1/96 - FROM dual
Both MIN and MAX
Default is 14; when you use the default - you repeat the heading every 14 rows.
Groups

27. You use the __________ keyword to change characteristics of a column.
STORAGE
MODIFY
SELECT DISTINCT menu FROM restaurant
+

28. Explicit data type conversion is preferable to Oracle's...
Implicit conversion
RIGHT LEFT JOIN
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
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

29. The ____________ icon allows you to execute multiple statements and emulates SQL *Plus as much as possible.
Committed
DICTIONARY
ALL_OBJECTS
RUN SCRIPT

30. What are the main components of a ROWID?
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.
Twice
Common column value
UNION operator

31. 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
RIGHT LEFT JOIN
KEEP INDEX
Common column value

32. All SQL statements contained within a script must end with a _______________ - even if they are done in SQL Developer.
FALSE
Semicolon or forward slash
Any
DECODE

33. When using the following data: NUMBER(10 -4) - the # 10 is called the __________.
INNER JOIN
Export Data
Precision
4000

34. When you want to run a script in either SQL*Plus or SQL Developer - you can use a ______ or the _________ command.
Nested
Multiple rows
@ or START
FALSE

35. You can simplify the writing of SQL statements by writing SQL _________ that generate and execute other SQL statements.
X
LIKE
Script
Optional

36. What is the command you would type into SQL*Plus if you needed to know the definition for each column of a table?
Multiple rows
V$
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
DICT_COLUMNS

37. _________ and __________ functions are opposites of each other and provide a value in a group of rows.
Dynamic SQL is used to be continuously updated by the background processes in the Oracle instance but never by the user.
The way NULL values are treated
Both MIN and MAX
2000

38. The data type definitions NUMBER(10) and NUMBER(10 -0) are the...
All
Same
Equijoin and correlated subquery
DICT_COLUMNS

39. Explain what a static data dictionary view is and how it is used
SELECT SYSDATE+1/96 - FROM dual
Export Data
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.

40. Dynamic views begin with a ___________.
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
V$
User-defined reports
All caps

41. Write an SQL statement for SQL *Plus in which you want any unique menu items to be displayed from the restaurant table
DICT_COLUMNS
Committed
SELECT DISTINCT menu FROM restaurant
Combine

42. The _______ function lets you perform if-then-else functionality with the SQL language.
DECODE
All caps
Surrogate
RENAME just_two_more_weeks TO finally_i

43. The time zone displacement value indicates the time difference from _______.
Nested
V$
SYSDATE
UTC

44. Subqueries can return...
Dynamic SQL is used to be continuously updated by the background processes in the Oracle instance but never by the user.
RENAME - COPY - DROP - TRUNCATE - LOCK - & COMMENT
TO_CHAR function
Multiple rows

45. The using clause of the ANSI join syntax always assumes an...
UNION operator
ADD
Three
Equijoin and identical column names

46. The query retrieves more than 5 to 15 percent of the rows
INTERSECT
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
The indexed column is part of an expression. In this case - consider creating a function-based index instead
Equijoin

47. Explain how the SPOOL command is used and what program it can be used in.
Nested
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
All
Fractional seconds

48. FEEDBACK
UTC
Location of the file
RENAME just_two_more_weeks TO finally_i
Command returns the number of records returned by a query.

49. The COUNT function is useful for determining whether a table has...
Leading-edge
Data
UNION
V$

50. ___________ subqueries allow you to reference columns from the outer query and execute the inner query repeatedly
Correlated
VALUES
Command returns the number of records returned by a query.
Any