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. The COUNT function uses the __________ wildcard.
UTC
**** 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
LENGTH
Asterisk

2. FEEDBACK
SELECT DISTINCT menu FROM restaurant
Primary key/foreign key
DESC dict;
Command returns the number of records returned by a query.

3. The time zone displacement value indicates the time difference from _______.
999999.9999
Non-matching rows
Same
UTC

4. What is the maximum value for a column defined as NUMBER(4 -2)?
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
99.99
**** 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
Data

5. 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.
Another null
Extra spaces
Three

6. A calculation with a null always yields...
Another null
Three
Run scripts
2000

7. The query retrieves more than 5 to 15 percent of the rows
DICT_COLUMNS
KEEP INDEX
BETWEEN
The indexed column is part of an expression. In this case - consider creating a function-based index instead

8. 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.
ALL_OBJECTS
RIGHT LEFT JOIN
Groups
Both MIN and MAX

9. Subqueries can return...
Implicit conversion
Hide data
Multiple rows
Equijoin

10. 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?
KEEP INDEX
DICTIONARY
All caps
ADD_MONTHS function

11. What is the data type you can use if you need an unlimited number of textual characters?
CLOB
INNER JOIN
FALSE
The way NULL values are treated

12. How many characters can be stored in the CHAR column/field?
X
INNER JOIN
Results
2000

13. What is the main difference between the NOT EXISTS and the NOT IN operators?
STORAGE
The way NULL values are treated
INNER JOIN
Committed

14. Explain what a static data dictionary view is and how it is used
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.
Control - Revoke - Define - TRUNCATE Manipulate - MERGE
Data
Precision

15. Which one of the following string functions tells you how many characters are in a string?
LENGTH
When the table is small (unless your business rules require you too)
Self-joins
Scalar

16. Explain what is found in the All Objects report folder in SQL Developer
Black
Lists all objects accessible for the chosen database connection. Also lists a helpful dependencies report for accessing change impact.
Both MIN and MAX
Common column value

17. Explicit data type conversion is preferable to Oracle's...
All caps
Implicit conversion
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
F12

18. You use the __________ keyword to change characteristics of a column.
MODIFY
VALUES clause of an INSERT statement
The indexed column is part of an expression. In this case - consider creating a function-based index instead
Multiple rows

19. When using the following data: NUMBER(10 -4) - the # 10 is called the __________.
Precision
Semicolon or forward slash
Null
MINUS

20. Users can only see changes made to a database once they have been...
COMMIT
Committed
MINUS
NATURAL JOIN

21. What is Oracle's most popular index storage structure?
UNION operator
RENAME - COPY - DROP - TRUNCATE - LOCK - & COMMENT
B-Tree Index
INNER JOIN

22. How many characters can you have using the VARCHAR data type?
Structured Query Language
CLOB
Optional
4000

23. _________ and __________ functions are opposites of each other and provide a value in a group of rows.
Both MIN and MAX
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
DICTIONARY
Run scripts

24. A _________ subquery returns a single column with a single row
Scalar
12:00:00 A.M
Static or dynamic
ADD

25. Explain how Dynamic SQL is used and give an example of a Dynamic SQL statement.
X
Run scripts
Has not changed the name
Dynamic SQL is used to be continuously updated by the background processes in the Oracle instance but never by the user.

26. You can __________ DISTINCT and a GROUP BY clause in the same SELECT statement.
ALL_OBJECTS
FALSE
INNER JOIN
Combine

27. 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
X
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
Business problems

28. UNION ALL does not sort - therefore it is less time consuming to use than the...
+
ANY
X
UNION operator

29. List the different types of data dictionary views.
Surrogate key
USER_ - ALL_ - DBA_ - and V$
Extra spaces
SELECT DISTINCT menu FROM restaurant

30. 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
SELECT SYSDATE+1/96 - FROM dual
Business problems
Semicolon or forward slash

31. The ____________ icon allows you to execute multiple statements and emulates SQL *Plus as much as possible.
Correlated
Dynamic SQL is used to be continuously updated by the background processes in the Oracle instance but never by the user.
RUN SCRIPT
Nested

32. The term ____________ ___________ is used to express a join that satisfies the join condition.
Primary key/foreign key
999999.9999
INNER JOIN
Recursive

33. A _____ is a query definition stored in the database that looks just like a table - but does not have any physical rows
Re-create
X
Equijoin
RENAME - COPY - DROP - TRUNCATE - LOCK - & COMMENT

34. SELECT * FROM instructor ORDER BY phone
Lists all objects accessible for the chosen database connection. Also lists a helpful dependencies report for accessing change impact.
V$
A correct statement
Orphan

35. LINESIZE
Default is 14; when you use the default - you repeat the heading every 14 rows.
LENGTH
Command determines the total number of characters SQL *Plus displays in on line before beginning a new line.
COMMIT

36. Self-joins are useful for performing comparisons and checking for ___________ in data.
Inconsistencies
Structured Query Language
Recursive
Any

37. What is the syntax used to indicate that you are using the Oracle Outer Join operator?
NATURAL JOIN
Export Data
+
LIKE

38. The focus of the logical data model is _____________
Equijoin
GROUP BY
Business problems
DICTIONARY

39. 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.
DECODE
Equijoin
FALSE
SELECT SYSDATE+1/96 - FROM dual

40. The data type definitions NUMBER(10) and NUMBER(10 -0) are the...
Same
SUM
When the table is small (unless your business rules require you too)
ROLLBACK

41. The _______ function adds values together for a group of rows.
Any
RIGHT LEFT JOIN
RENAME just_two_more_weeks TO finally_i
SUM

42. 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.
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
Default is 14; when you use the default - you repeat the heading every 14 rows.
Equijoin and correlated subquery
VALUES

43. To equijoin a table with another table involves matching the...
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
Equijoin
Common column value
COUNT(registration_date) - AVG (capacity) - MIN (capacity) - MAX (capacity)

44. List the steps performed by a correlated subquery.
SELECT SYSDATE+1/96 - FROM dual
VALUES clause of an INSERT statement
**** 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
DICTIONARY

45. To revert back to a state that happened before you ran your change statement - you issue a ____________ command.
DECODE
Precision
RENAME just_two_more_weeks TO finally_i
ROLLBACK

46. Explain how the SPOOL command is used and what program it can be used in.
MODIFY
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
Both MIN and MAX
CLOB

47. What is the Oracle data dictionary called that contains a set of tables and views containing the data about the database?
DECODE
ALL_OBJECTS
ANSI
Orphan

48. Comparison operators can compare multiple _________________.
BETWEEN
TO_CHAR function
INTERSECT
Columns

49. 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

50. The ____________ keywords and the USING clause of the ANSI join syntax are mutually exclusive.
NATURAL JOIN
4
Columns
RENAME - COPY - DROP - TRUNCATE - LOCK - & COMMENT