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. When you have issued a DELETE command - you can still ________ those rows and restore the information.
Retrieve
F12
GROUP BY
Another null

2. A calculation with a null always yields...
Equijoin
All
Another null
Details

3. Queries that are found in parentheses are done first - just as in the order of operations when doing...
Scalar
Mathematical equations
Committed
Testing functions

4. UNION ALL does not sort - therefore it is less time consuming to use than the...
FALSE
DECODE
UNION operator
99.99

5. The focus of the logical data model is _____________
Groups
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.
Run scripts
Business problems

6. Which one of the following string functions tells you how many characters are in a string?
Common column value
Committed
LENGTH
Groups

7. When using the following data: NUMBER(10 -4) - the # 10 is called the __________.
Run scripts
DICT_COLUMNS
STORAGE
Precision

8. Explain what a static data dictionary view is and how it is used
X
VALUES clause of an INSERT statement
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.
DICTIONARY

9. The COUNT function uses the __________ wildcard.
Self-joins
Asterisk
Combine
Same

10. What are the main components of a ROWID?
ROLLBACK
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 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.
Command determines the total number of characters SQL *Plus displays in on line before beginning a new line.

11. Explain how Substitution Variables are used when writing scripts.
Groups
Rounded edges
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.
DICTIONARY

12. SQL*Plus is used more than SQL Developer when you need to...
Run scripts
ADD
**** 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
TO_CHAR function

13. The ________________ is a type of statement whereby you retrieve data that exists in one table - but not in another.
Time zone
X
4
MINUS

14. 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.
Command determines the total number of characters SQL *Plus displays in on line before beginning a new line.
Script
RIGHT LEFT JOIN
Month ddth - yyyy

15. Explain what is found in the All Objects report folder in SQL Developer
Asterisk
Committed
4000
Lists all objects accessible for the chosen database connection. Also lists a helpful dependencies report for accessing change impact.

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

17. Explain Flashback queries and how they are used. Give an example of a FLASHBACK_TRANSACTION query and explain what it does row by row.

Warning: Invalid argument supplied for foreach() in /var/www/html/basicversity.com/show_quiz.php on line 183

18. The COUNT function is useful for determining whether a table has...
Data
The way NULL values are treated
When the table is small (unless your business rules require you too)
X

19. Joins involving multiple columns must always follow the ____________ relationship path.
VALUES clause of an INSERT statement
A correct statement
All
Primary key/foreign key

20. SELECT LIST of a subquery in an INSERT statement
STORAGE
LIKE
SET clause of an UPDATE statement
Primary key/foreign key

21. When using the following data: NUMBER(10 -4) - the lowest number you can possibly have is __________.
999999.9999
Actual column
X
Same

22. Explain in detail the impact of INDEXES and how they are used by Oracle.
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
SUM
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
Correlated

23. How many characters can be stored in the CHAR column/field?
2000
Semicolon or forward slash
Has not changed the name
Testing functions

24. Explain how you can optimize your queries with subqueries and the main advantage of doing so.
Details
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
Structured Query Language
Primary key/foreign key

25. The key that most database designers prefer and is chosen by the system is the _____________ key.
DECODE
INNER JOIN
Surrogate
Any

26. What is Oracle's most popular index storage structure?
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
Columns
B-Tree Index
RIGHT LEFT JOIN

27. Explain how the SPOOL command is used and what program it can be used in.
RIGHT LEFT JOIN
Semicolon or forward slash
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
Precision

28. To restart a sequence at a lower number - you can drop and ________ the sequence.
Time zone
12:00:00 A.M
Re-create
Any

29. What is the command you would type into SQL*Plus if you needed to know the definition for each column of a table?
DICT_COLUMNS
LIKE
VALUES
Fractional seconds

30. Explain the differences in how an ANSI Full Outer Join and a Full Outer Join using the UNION Operator work
Location of the file
Command determines the total number of characters SQL *Plus displays in on line before beginning a new line.
X
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

31. _________________ relationships are always optional relationships.
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.
Groups
Recursive
Dynamic SQL is used to be continuously updated by the background processes in the Oracle instance but never by the user.

32. The __________ operator is inclusive of the two values specified.
Three
Scale
BETWEEN
Data

33. The ROWID pseudocolumn is not an ________- but it acts like one.
Command returns the number of records returned by a query.
UNION operator
Parent table
Actual column

34. When disabling a unique or primary key - you can keep the index if you specify the __________________ clause in the ALTER TABLE statement.
KEEP INDEX
LENGTH
ADD_MONTHS function
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

35. List 4 aggregate functions
COUNT(registration_date) - AVG (capacity) - MIN (capacity) - MAX (capacity)
RUN SCRIPT
DICT_COLUMNS
X

36. Users can only see changes made to a database once they have been...
Equijoin and correlated subquery
Committed
Inconsistencies
DECODE

37. List the different types of data dictionary views.
Default is 14; when you use the default - you repeat the heading every 14 rows.
USER_ - ALL_ - DBA_ - and V$
MODIFY
V$

38. ____________ are useful for analyzing and exploring the relationships within your data
Self-joins
UNION
DROP INDEX need_to_pass_i
SELECT SYSDATE+1/96 - FROM dual

39. Instead of using the Oracle Outer Join Operator or the ANSI syntax - you can achieve the same result with two SQL statements: ____________ and a ____________
Equijoin and correlated subquery
User-defined reports
STORAGE
Extra spaces

40. PAGESIZE
**** 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
Committed
Default is 14; when you use the default - you repeat the heading every 14 rows.

41. What is the most common DATE format found in SQL?
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.
Committed
DESC dict;
DD-MON-YY

42. __________________ inserts the current date and time.
**** 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
Nested
@ or START
SYSDATE

43. What is the keyboard shortcut for the ROLLBACK command?
Structured Query Language
F12
SUM
A correct statement

44. What is the first column of a composite index called?
Columns
Dynamic SQL is used to be continuously updated by the background processes in the Oracle instance but never by the user.
Any
Leading-edge

45. A join across three tables can be expressed with the ________ join syntax.
FALSE
BETWEEN
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.
ANSI

46. Which format mask displays December 31st - 1999?
Groups
Precision
Month ddth - yyyy
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

47. LINESIZE
DICT_COLUMNS
B-Tree Index
Command determines the total number of characters SQL *Plus displays in on line before beginning a new line.
Time zone

48. The _____________ clause determines how rows are grouped.
Parent table
12:00:00 A.M
GROUP BY
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

49. You use the __________ keyword to change characteristics of a column.
MODIFY
Optional
LIKE
BETWEEN

50. Write the syntax to rename index just_two_more_weeks_i to finally_i
LENGTH
**** 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
RENAME just_two_more_weeks TO finally_i
Script