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. NUMBER functions can be...
Twice
X
UTC
Nested

2. When using the data NUMBER(10 -4) there will be _______ digits following the decimal point.
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.
Surrogate key
TO_CHAR function
4

3. When column names on the tables are different - you use the ______ condition.
VALUES clause of an INSERT statement
ON
2000
ROLLBACK

4. Another name for a data dictionary view is __________________ or _________________.
Surrogate
Static or dynamic
SELECT DISTINCT menu FROM restaurant
Results

5. The key that most database designers prefer and is chosen by the system is the _____________ key.
Surrogate
RENAME - COPY - DROP - TRUNCATE - LOCK - & COMMENT
USER_ - ALL_ - DBA_ - and V$
Actual column

6. The COUNT function is useful for determining whether a table has...
Optional
Data
Command determines the total number of characters SQL *Plus displays in on line before beginning a new line.
Leading-edge

7. Users can only see changes made to a database once they have been...
Equijoin and identical column names
Committed
Hide data
Extra spaces

8. What is the syntax used to indicate that you are using the Oracle Outer Join operator?
+
UTC
Any
X

9. _________________ relationships are always optional relationships.
Black
SELECT SYSDATE+1/96 - FROM dual
Results
Recursive

10. Explicit data type conversion is preferable to Oracle's...
Groups
All
Implicit conversion
RIGHT LEFT JOIN

11. In a view you can give a column a different name than it has in the...
Both MIN and MAX
Implicit conversion
Parent table
SYSDATE

12. When you create a report in SQL Developer all the column names must match identically the names of the columns found in the tables you are referencing.
Command determines the total number of characters SQL *Plus displays in on line before beginning a new line.
MINUS
FALSE
12:00:00 A.M

13. Which format mask displays December 31st - 1999?
RENAME - COPY - DROP - TRUNCATE - LOCK - & COMMENT
Equijoin
Month ddth - yyyy
Fractional seconds

14. _________ rows are not allowed in the relational model.
Nested
Orphan
USER_ - ALL_ - DBA_ - and V$
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.

15. The query retrieves more than 5 to 15 percent of the rows
Asterisk
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.
Semicolon or forward slash
The indexed column is part of an expression. In this case - consider creating a function-based index instead

16. What is Oracle's most popular index storage structure?
B-Tree Index
LIKE
Crow's foot
2000

17. What do views do that makes them so useful for security?
Twice
Scalar
X
Hide data

18. The _______ function adds values together for a group of rows.
DICTIONARY
Equijoin and identical column names
Running a script file
SUM

19. It is always good practice to include the old values in the WHERE clause of UPDATE to ensure that another session or user _________________ in the meantime.
Has not changed the name
Same
SYSDATE
X

20. It is considered good form to put all SQL commands in...
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.
Three
All caps
Columns

21. You use the __________ keyword to change characteristics of a column.
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.
MODIFY
Data
Time zone

22. The __________ operator is inclusive of the two values specified.
Month ddth - yyyy
BETWEEN
Any
The indexed column is part of an expression. In this case - consider creating a function-based index instead

23. The COUNT function uses the __________ wildcard.
CLOB
Any
Semicolon or forward slash
Asterisk

24. The DUAL table can be used for...
Testing functions
Same
STORAGE
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

25. List 4 aggregate functions
Logical unit of work
Rounded edges
Lists all objects accessible for the chosen database connection. Also lists a helpful dependencies report for accessing change impact.
COUNT(registration_date) - AVG (capacity) - MIN (capacity) - MAX (capacity)

26. The _______ operator determines common rows.
Testing functions
Command determines the total number of characters SQL *Plus displays in on line before beginning a new line.
Null
INTERSECT

27. ____________ are useful for analyzing and exploring the relationships within your data
GROUP BY
Self-joins
Running a script file
Default is 14; when you use the default - you repeat the heading every 14 rows.

28. Explain how the SPOOL command is used and what program it can be used in.
Data
4
RENAME just_two_more_weeks TO finally_i
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

29. The RTRIM function is useful for eliminating ________ in a string.
Testing functions
**** 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
ADD_MONTHS function
Extra spaces

30. When writing the syntax for finding information on three or more tables - the parenthesis around the ON clause is...
FALSE
Surrogate
Structured Query Language
Optional

31. The ___________ operator tests whether a matching row cannot be found.
B-Tree Index
IN ANY ALL SOME
X
Primary key/foreign key

32. A _________ subquery returns a single column with a single row
FALSE
Scalar
NATURAL JOIN
Multiple rows

33. Write a statement that drops the index need_to_pass_i
INNER JOIN
VALUES
DROP INDEX need_to_pass_i
UNION operator

34. Converting a text literal to DATE format requires the use of the...
X
TO_CHAR function
Equijoin and identical column names
B-Tree Index

35. What does the following function return? SELECT LENGTH(NULL) - FROM dual
X
LIKE
Null
BETWEEN

36. When using the following data: NUMBER(10 -4) - the lowest number you can possibly have is __________.
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.
ADD_MONTHS function
999999.9999
Hide data

37. Explain how you can optimize your queries with subqueries and the main advantage of doing so.
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
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 the table is small (unless your business rules require you too)
Columns

38. When you INSERT new information into a table - it is followed with a _______ keyword that contains the information that is going to be added to the table.
Both MIN and MAX
Leading-edge
Business problems
VALUES

39. A transaction is a...
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.
Logical unit of work
Details
Asterisk

40. Checks whether any value in the list makes the condition true.
Any
Recursive
ROLLBACK
Leading-edge

41. Explain what a static data dictionary view is and how it is used
SELECT DISTINCT menu FROM restaurant
Common column value
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.
UNION operator

42. When using the following data: NUMBER(10 -4) - the # 10 is called the __________.
Recursive
Precision
Rounded edges
UNION

43. List the reasons that a subquery could not be unnested.
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.
User-defined reports
Common column value
X

44. To restart a sequence at a lower number - you can drop and ________ the sequence.
Re-create
ANY
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.
Command returns the number of records returned by a query.

45. To place a line comment in your SQL statements - you first place a // at the beginning of the line.
V$
FALSE
SUM
Results

46. SQL*Plus is used more than SQL Developer when you need to...
Twice
F12
Run scripts
ANSI

47. The same function can be used ______ in a SELECT statement.
DECODE
COUNT(registration_date) - AVG (capacity) - MIN (capacity) - MAX (capacity)
99.99
Twice

48. What does SQL stand for?
Month ddth - yyyy
Command returns the number of records returned by a query.
Structured Query Language
Equijoin and correlated subquery

49. What is the data type you can use if you need an unlimited number of textual characters?
**** 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
12:00:00 A.M
DICT_COLUMNS
CLOB

50. ___________ subqueries allow you to reference columns from the outer query and execute the inner query repeatedly
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.
Correlated
RUN SCRIPT
Non-matching rows