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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 _________ subquery returns a single column with a single row
Committed
STORAGE
Scalar
ROLLBACK

2. How many characters can you have using the VARCHAR data type?
12:00:00 A.M
4000
INTERSECT
All caps

3. The ROWID pseudocolumn is not an ________- but it acts like one.
ON
Default is 14; when you use the default - you repeat the heading every 14 rows.
Actual column
ANY

4. Comparison operators can compare multiple _________________.
Columns
Precision
BETWEEN
COMMIT

5. SELECT LIST of a subquery in an INSERT statement
Any
Groups
USER_ - ALL_ - DBA_ - and V$
SET clause of an UPDATE statement

6. Joins involving multiple columns must always follow the ____________ relationship path.
Location of the file
Equijoin and identical column names
Control - Revoke - Define - TRUNCATE Manipulate - MERGE
Primary key/foreign key

7. Returns rows if the condition is true for all the values in the list
Command determines the total number of characters SQL *Plus displays in on line before beginning a new line.
RENAME just_two_more_weeks TO finally_i
All
Non-matching rows

8. When is it not a good idea to use an index?
When the table is small (unless your business rules require you too)
DESC dict;
X
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

9. The ________________ is a type of statement whereby you retrieve data that exists in one table - but not in another.
MINUS
RUN SCRIPT
All caps
Extra spaces

10. When you have issued a DELETE command - you can still ________ those rows and restore the information.
BETWEEN
B-Tree Index
Retrieve
Optional

11. The time zone displacement value indicates the time difference from _______.
All caps
UTC
TO_CHAR function
4

12. SQL*Plus is used more than SQL Developer when you need to...
Scalar
Run scripts
KEEP INDEX
Implicit conversion

13. ____________ are useful for analyzing and exploring the relationships within your data
+
Null
Scale
Self-joins

14. In SQL Developer field names and table names are shown in the color _______.
MINUS
Re-create
Black
Nested

15. Self-joins are useful for performing comparisons and checking for ___________ in data.
Rounded edges
SET clause of an UPDATE statement
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.
Inconsistencies

16. A _____ is a query definition stored in the database that looks just like a table - but does not have any physical rows
Non-matching rows
IN ANY ALL SOME
X
Command determines the total number of characters SQL *Plus displays in on line before beginning a new line.

17. Which format mask displays December 31st - 1999?
Committed
X
Month ddth - yyyy
2000

18. NUMBER functions can be...
SYSDATE
Nested
BETWEEN
NATURAL JOIN

19. Checks whether any value in the list makes the condition true.
Any
Data
Inconsistencies
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.

20. What is the first column of a composite index called?
COMMIT
Leading-edge
A correct statement
Orphan

21. The using clause of the ANSI join syntax always assumes an...
Structured Query Language
Control - Revoke - Define - TRUNCATE Manipulate - MERGE
Equijoin and identical column names
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

22. 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.
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.
User-defined reports
X

23. The NEXTVAL and CURRVAL pseudocolumns can be used in which of the following SQL constructs? Select all that apply.
Surrogate key
Business problems
Asterisk
VALUES clause of an INSERT statement

24. _________________ relationships are always optional relationships.
Recursive
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.
12:00:00 A.M
Common column value

25. List the reasons that a subquery could not be unnested.
Hide data
F12
UNION
X

26. The _______ function adds values together for a group of rows.
UTC
SUM
X
Correlated

27. What does SQL stand for?
A correct statement
Multiple rows
Structured Query Language
DICTIONARY

28. List the steps performed by a correlated subquery.
Data
Command returns the number of records returned by a query.
Equijoin and identical column names
**** 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

29. Write the syntax to rename index just_two_more_weeks_i to finally_i
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
RENAME just_two_more_weeks TO finally_i
Equijoin
Running a script file

30. To revert back to a state that happened before you ran your change statement - you issue a ____________ command.
Any
RIGHT LEFT JOIN
ROLLBACK
DICT_COLUMNS

31. Checks whether any value in the list makes the condition true.
Any
DECODE
The indexed column is part of an expression. In this case - consider creating a function-based index instead
Inconsistencies

32. How many characters can be stored in the CHAR column/field?
Surrogate key
Command determines the total number of characters SQL *Plus displays in on line before beginning a new line.
Self-joins
2000

33. What is the name of the key automatically generated from a sequence?
FALSE
Null
Surrogate key
Extra spaces

34. The _______ operator determines common rows.
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
X
SET clause of an UPDATE statement
INTERSECT

35. The TIMESTAMP WITH LOCAL TIME ZONE data type allows...
Fractional seconds
ON
DICT_COLUMNS
COUNT(registration_date) - AVG (capacity) - MIN (capacity) - MAX (capacity)

36. What is the command you would type into SQL*Plus if you needed to know the definition for each column of a table?
Details
Crow's foot
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
DICT_COLUMNS

37. When you want to run a script in either SQL*Plus or SQL Developer - you can use a ______ or the _________ command.
Running a script file
SUM
INNER JOIN
@ or START

38. It is considered good form to put all SQL commands in...
All caps
RENAME just_two_more_weeks TO finally_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
LENGTH

39. UNION ALL does not sort - therefore it is less time consuming to use than the...
A correct statement
Has not changed the name
X
UNION operator

40. Write a statement for SQL*Plus that shows the dictionary.
DESC dict;
ANSI
RENAME - COPY - DROP - TRUNCATE - LOCK - & COMMENT
Fractional seconds

41. When column names on the tables are different - you use the ______ condition.
MINUS
B-Tree Index
The indexed column is part of an expression. In this case - consider creating a function-based index instead
ON

42. When using the following data: NUMBER(10 -4) - the # 4 is called the __________.
Combine
Scale
RENAME just_two_more_weeks TO finally_i
SELECT SYSDATE+1/96 - FROM dual

43. In a view you can give a column a different name than it has in the...
Parent table
2000
B-Tree Index
LENGTH

44. SELECT * FROM instructor ORDER BY phone
Business problems
Retrieve
A correct statement
Combine

45. Explain how you can optimize your queries with subqueries and the main advantage of doing so.
TO_CHAR function
ADD
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
Has not changed the name

46. What do views do that makes them so useful for security?
Has not changed the name
Hide data
Business problems
Implicit conversion

47. When writing the syntax for finding information on three or more tables - the parenthesis around the ON clause is...
Actual column
Optional
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
Leading-edge

48. What is the maximum value for a column defined as NUMBER(4 -2)?
Command returns the number of records returned by a query.
SELECT DISTINCT menu FROM restaurant
Surrogate
99.99

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.

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50. The ____________ icon allows you to execute multiple statements and emulates SQL *Plus as much as possible.
Both MIN and MAX
FALSE
RUN SCRIPT
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.