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. A transaction is a...
Logical unit of work
UNION
Asterisk
Any

2. The COUNT function is useful for determining whether a table has...
Black
99.99
Data
User-defined reports

3. 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.
Mathematical equations
ADD_MONTHS function
Committed
Has not changed the name

4. List 4 aggregate functions
Business problems
Crow's foot
DICTIONARY
COUNT(registration_date) - AVG (capacity) - MIN (capacity) - MAX (capacity)

5. Queries that are found in parentheses are done first - just as in the order of operations when doing...
IN ANY ALL SOME
Retrieve
All caps
Mathematical equations

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

7. The DUAL table can be used for...
@ or START
Details
Testing functions
Non-matching rows

8. The data type definitions NUMBER(10) and NUMBER(10 -0) are the...
SELECT DISTINCT menu FROM restaurant
Same
@ or START
Parent table

9. All SQL statements contained within a script must end with a _______________ - even if they are done in SQL Developer.
Control - Revoke - Define - TRUNCATE Manipulate - MERGE
FALSE
MINUS
Semicolon or forward slash

10. What is the first column of a composite index called?
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
Leading-edge
X
NATURAL JOIN

11. Explain how Dynamic SQL is used and give an example of a Dynamic SQL statement.
Dynamic SQL is used to be continuously updated by the background processes in the Oracle instance but never by the user.
Leading-edge
STORAGE
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

12. LINESIZE
Command determines the total number of characters SQL *Plus displays in on line before beginning a new line.
USER_ - ALL_ - DBA_ - and V$
Groups
Self-joins

13. Which one of the following string functions tells you how many characters are in a string?
LENGTH
IN ANY ALL SOME
Crow's foot
INTERSECT

14. Write an SQL statement for SQL *Plus in which you want any unique menu items to be displayed from the restaurant table
Rounded edges
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.
SELECT DISTINCT menu FROM restaurant
Static or dynamic

15. How many characters can you have using the VARCHAR data type?
4000
@ or START
Multiple rows
Data

16. What is the data type you can use if you need an unlimited number of textual characters?
Logical unit of work
Nested
CLOB
Three

17. What does the following function return? SELECT LENGTH(NULL) - FROM dual
ALL_OBJECTS
Same
Null
Export Data

18. When writing the syntax for finding information on three or more tables - the parenthesis around the ON clause is...
Optional
F12
UTC
MINUS

19. SELECT LIST of a subquery in an INSERT statement
Command determines the total number of characters SQL *Plus displays in on line before beginning a new line.
Crow's foot
KEEP INDEX
SET clause of an UPDATE statement

20. You can use the ________________ to subtract months from a given date.
Has not changed the name
The indexed column is part of an expression. In this case - consider creating a function-based index instead
ADD_MONTHS function
User-defined reports

21. You use the __________ keyword to change characteristics of a column.
Mathematical equations
Re-create
12:00:00 A.M
MODIFY

22. It is considered good form to put all SQL commands in...
Null
SUM
RENAME just_two_more_weeks TO finally_i
All caps

23. Explain how you can optimize your queries with subqueries and the main advantage of doing so.
Command determines the total number of characters SQL *Plus displays in on line before beginning a new line.
Running a script file
Both MIN and MAX
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

24. Write a statement that drops the index need_to_pass_i
**** 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
Any
F12
DROP INDEX need_to_pass_i

25. An outer join includes the result rows returned by an __________ plus extra rows where no matches are found.
Equijoin
Correlated
Implicit conversion
Primary key/foreign key

26. What is the name of the key automatically generated from a sequence?
Both MIN and MAX
Script
Surrogate key
COMMIT

27. The TRUNC function on a date without a format model truncates the timestamp to...
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.
All caps
12:00:00 A.M
CLOB

28. The using clause of the ANSI join syntax always assumes an...
Equijoin and identical column names
Dynamic SQL is used to be continuously updated by the background processes in the Oracle instance but never by the user.
Primary key/foreign key
Committed

29. What is the most common DATE format found in SQL?
DD-MON-YY
Default is 14; when you use the default - you repeat the heading every 14 rows.
Recursive
Leading-edge

30. The _______ operator determines common rows.
Run scripts
User-defined reports
INTERSECT
X

31. When using the following data: NUMBER(10 -4) - the lowest number you can possibly have is __________.
999999.9999
Structured Query Language
USER_ - ALL_ - DBA_ - and V$
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.

32. 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.
VALUES
FALSE
UNION
Committed

33. When using the following data: NUMBER(10 -4) - the # 4 is called the __________.
Rounded edges
X
Scale
INTERSECT

34. Explain how Substitution Variables are used when writing scripts.
Export Data
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.
Running a script file
99.99

35. The key that most database designers prefer and is chosen by the system is the _____________ key.
UNION operator
Groups
When the table is small (unless your business rules require you too)
Surrogate

36. The TIMESTAMP WITH LOCAL TIME ZONE data type allows...
Scalar
4
DECODE
Fractional seconds

37. The NEXTVAL and CURRVAL pseudocolumns can be used in which of the following SQL constructs? Select all that apply.
IN ANY ALL SOME
VALUES clause of an INSERT statement
ROLLBACK
DECODE

38. The __________ operator is inclusive of the two values specified.
Another null
BETWEEN
KEEP INDEX
4

39. The ___________ operator tests whether a matching row cannot be found.
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
X
RUN SCRIPT
Equijoin

40. The same function can be used ______ in a SELECT statement.
Actual column
Twice
V$
Correlated

41. NUMBER functions can be...
LIKE
Null
RUN SCRIPT
Nested

42. You can __________ DISTINCT and a GROUP BY clause in the same SELECT statement.
Combine
DICTIONARY
INTERSECT
4000

43. Explain why constraints are used when building tables.

44. When you run a script in SQL*Plus you must give the...
FALSE
2000
ON
Location of the file

45. 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?
X
Re-create
DICTIONARY
COMMIT

46. Explain how Oracle treats locks when a database is being updated and needs to be viewed by other users.
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
RUN SCRIPT
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
Recursive

47. The focus of the logical data model is _____________
Data
Both MIN and MAX
Business problems
Retrieve

48. When disabling a unique or primary key - you can keep the index if you specify the __________________ clause in the ALTER TABLE statement.
KEEP INDEX
Multiple rows
Optional
Implicit conversion

49. What is the syntax used to indicate that you are using the Oracle Outer Join operator?
BETWEEN
+
X
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.

50. _________________ relationships are always optional relationships.
Recursive
Parent table
ADD_MONTHS function
Details