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. SQL*Plus is used more than SQL Developer when you need to...
Surrogate key
Multiple rows
RIGHT LEFT JOIN
Run scripts

2. 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.
Equijoin and correlated subquery
ALL_OBJECTS
X

3. What do views do that makes them so useful for security?
Hide data
Self-joins
The way NULL values are treated
LIKE

4. When using the data NUMBER(10 -4) there will be _______ digits following the decimal point.
Results
4
**** 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
DICT_COLUMNS

5. NUMBER functions can be...
2000
Both MIN and MAX
Nested
Combine

6. Explain how Dynamic SQL is used and give an example of a Dynamic SQL statement.
SYSDATE
Dynamic SQL is used to be continuously updated by the background processes in the Oracle instance but never by the user.
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
Asterisk

7. What does SQL stand for?
V$
Structured Query Language
Extra spaces
Crow's foot

8. How many characters can be stored in the CHAR column/field?
2000
Results
DICT_COLUMNS
SELECT SYSDATE+1/96 - FROM dual

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

10. List 6 Table-Related Menu Choices
Semicolon or forward slash
RENAME - COPY - DROP - TRUNCATE - LOCK - & COMMENT
+
Running a script file

11. ____________ are useful for analyzing and exploring the relationships within your data
Self-joins
MODIFY
USER_ - ALL_ - DBA_ - and V$
KEEP INDEX

12. A _________ subquery returns a single column with a single row
Scalar
X
All caps
Business problems

13. Explain how Oracle treats locks when a database is being updated and needs to be viewed by other users.
UNION
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
BETWEEN
FALSE

14. When writing the syntax for finding information on three or more tables - the parenthesis around the ON clause is...
Script
Optional
FALSE
Common column value

15. In SQL Developer field names and table names are shown in the color _______.
Black
RIGHT LEFT JOIN
COUNT(registration_date) - AVG (capacity) - MIN (capacity) - MAX (capacity)
BETWEEN

16. List 4 aggregate functions
COUNT(registration_date) - AVG (capacity) - MIN (capacity) - MAX (capacity)
12:00:00 A.M
USER_ - ALL_ - DBA_ - and V$
Logical unit of work

17. Explain the steps needed to run a script in SQL Developer
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.
Testing functions
User-defined reports
V$

18. Write a statement that drops the index need_to_pass_i
DROP INDEX need_to_pass_i
Null
999999.9999
F12

19. The ______ operator compares a list of values for equivalency
Three
INNER JOIN
SELECT SYSDATE+1/96 - FROM dual
ANY

20. What is the most common DATE format found in SQL?
DICT_COLUMNS
All
DD-MON-YY
Crow's foot

21. FEEDBACK
UNION operator
Command returns the number of records returned by a query.
Three
Inconsistencies

22. The TIMESTAMP WITH LOCAL TIME ZONE data type allows...
Non-matching rows
INNER JOIN
RUN SCRIPT
Fractional seconds

23. Explain how the SPOOL command is used and what program it can be used in.
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
Correlated
Scale
ANSI

24. 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.
Columns
Recursive
NATURAL JOIN

25. An outer join includes the result rows returned by an __________ plus extra rows where no matches are found.
Command determines the total number of characters SQL *Plus displays in on line before beginning a new line.
UNION operator
Equijoin
Details

26. List the different types of data dictionary views.
Month ddth - yyyy
LENGTH
When the table is small (unless your business rules require you too)
USER_ - ALL_ - DBA_ - and V$

27. The data type definitions NUMBER(10) and NUMBER(10 -0) are the...
Same
Equijoin and correlated subquery
999999.9999
Run scripts

28. What is Oracle's most popular index storage structure?
B-Tree Index
Same
IN ANY ALL SOME
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

29. Users can only see changes made to a database once they have been...
Committed
COUNT(registration_date) - AVG (capacity) - MIN (capacity) - MAX (capacity)
IN ANY ALL SOME
Time zone

30. The ___________ operator tests whether a matching row cannot be found.
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
RENAME just_two_more_weeks TO finally_i
99.99

31. 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.
SUM
Groups
RIGHT LEFT JOIN
Three

32. Explain the differences in how an ANSI Full Outer Join and a Full Outer Join using the UNION Operator work
User-defined reports
X
SELECT DISTINCT menu FROM restaurant
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

33. Explain how you can optimize your queries with subqueries and the main advantage of doing so.
Export Data
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
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
Surrogate

34. The ALTER SESSION statement can change the session's...
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
MINUS
Time zone
Equijoin

35. The COUNT function uses the __________ wildcard.
DICT_COLUMNS
Asterisk
ADD_MONTHS function
X

36. In a view you can give a column a different name than it has in the...
VALUES
Parent table
Default is 14; when you use the default - you repeat the heading every 14 rows.
2000

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

38. The _____________ clause determines how rows are grouped.
GROUP BY
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
Command determines the total number of characters SQL *Plus displays in on line before beginning a new line.
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

39. When using the following data: NUMBER(10 -4) - the # 4 is called the __________.
Recursive
Scale
RENAME - COPY - DROP - TRUNCATE - LOCK - & COMMENT
Parent table

40. When you run a script in SQL*Plus you must give the...
Location of the file
12:00:00 A.M
Rounded edges
Lists all objects accessible for the chosen database connection. Also lists a helpful dependencies report for accessing change impact.

41. What does the following function return? SELECT LENGTH(NULL) - FROM dual
Default is 14; when you use the default - you repeat the heading every 14 rows.
Command determines the total number of characters SQL *Plus displays in on line before beginning a new line.
Null
BETWEEN

42. Explain what is found in the All Objects report folder in SQL Developer
Common column value
Optional
Lists all objects accessible for the chosen database connection. Also lists a helpful dependencies report for accessing change impact.
VALUES

43. 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.
Logical unit of work
Both MIN and MAX
VALUES
LENGTH

44. When disabling a unique or primary key - you can keep the index if you specify the __________________ clause in the ALTER TABLE statement.
Command determines the total number of characters SQL *Plus displays in on line before beginning a new line.
FALSE
KEEP INDEX
NATURAL JOIN

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

46. The key that most database designers prefer and is chosen by the system is the _____________ key.
DECODE
Running a script file
When the table is small (unless your business rules require you too)
Surrogate

47. UNION ALL does not sort - therefore it is less time consuming to use than the...
INTERSECT
UNION operator
Three
SELECT SYSDATE+1/96 - FROM dual

48. You can __________ DISTINCT and a GROUP BY clause in the same SELECT statement.
User-defined reports
12:00:00 A.M
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.
Combine

49. What is the first column of a composite index called?
Extra spaces
Any
Leading-edge
All caps

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