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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. Explain how Substitution Variables are used when writing scripts.
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.
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.
UNION
Orphan

2. Explicit data type conversion is preferable to Oracle's...
999999.9999
Implicit conversion
Running a script file
Equijoin and identical column names

3. The same function can be used ______ in a SELECT statement.
Twice
The indexed column is part of an expression. In this case - consider creating a function-based index instead
UNION operator
Mathematical equations

4. Which one of the following string functions tells you how many characters are in a string?
GROUP BY
TO_CHAR function
LENGTH
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.

5. _________________ relationships are always optional relationships.
Recursive
Time zone
99.99
B-Tree Index

6. Another name for a data dictionary view is __________________ or _________________.
Non-matching rows
ADD
Three
Static or dynamic

7. If a graphical representation of a table's box has __________ it means that the relationship is identifying.
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
Rounded edges
Implicit conversion
KEEP INDEX

8. ____________ are useful for analyzing and exploring the relationships within your data
Self-joins
SELECT DISTINCT menu FROM restaurant
**** 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
Three

9. The DUAL table can be used for...
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
Testing functions
ON
VALUES

10. How many characters can be stored in the CHAR column/field?
2000
Any
12:00:00 A.M
Fractional seconds

11. What is the data type you can use if you need an unlimited number of textual characters?
RENAME just_two_more_weeks TO finally_i
Scale
CLOB
SUM

12. __________________ inserts the current date and time.
Actual column
MODIFY
Semicolon or forward slash
SYSDATE

13. You can simplify the writing of SQL statements by writing SQL _________ that generate and execute other SQL statements.
X
Columns
Script
Time zone

14. What is the maximum value for a column defined as NUMBER(4 -2)?
SET clause of an UPDATE statement
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.
BETWEEN
99.99

15. Match each of the SQL commands on the left with a verb from the list.
Command determines the total number of characters SQL *Plus displays in on line before beginning a new line.
Structured Query Language
Control - Revoke - Define - TRUNCATE Manipulate - MERGE
The indexed column is part of an expression. In this case - consider creating a function-based index instead

16. SELECT * FROM instructor ORDER BY phone
A correct statement
999999.9999
STORAGE
Re-create

17. 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
Default is 14; when you use the default - you repeat the heading every 14 rows.
Logical unit of work
NATURAL JOIN

18. What do views do that makes them so useful for security?
Hide data
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
Three
ALL_OBJECTS

19. The query retrieves more than 5 to 15 percent of the rows
Precision
DD-MON-YY
Lists all objects accessible for the chosen database connection. Also lists a helpful dependencies report for accessing change impact.
The indexed column is part of an expression. In this case - consider creating a function-based index instead

20. What is the command you would type into SQL*Plus if you needed to know the definition for each column of a table?
UNION
DICT_COLUMNS
Control - Revoke - Define - TRUNCATE Manipulate - MERGE
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

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

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22. 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
Optional
Mathematical equations

23. The TIMESTAMP WITH LOCAL TIME ZONE data type allows...
Inconsistencies
RIGHT LEFT JOIN
Fractional seconds
Groups

24. The ____________ keywords and the USING clause of the ANSI join syntax are mutually exclusive.
DICT_COLUMNS
TO_CHAR function
Orphan
NATURAL JOIN

25. What is Oracle's most popular index storage structure?
Data
All
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
B-Tree Index

26. When using the following data: NUMBER(10 -4) - the # 10 is called the __________.
LIKE
KEEP INDEX
Precision
All

27. 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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28. The data type definitions NUMBER(10) and NUMBER(10 -0) are the...
Has not changed the name
Same
12:00:00 A.M
Static or dynamic

29. The NEXTVAL and CURRVAL pseudocolumns can be used in which of the following SQL constructs? Select all that apply.
User-defined reports
Run scripts
VALUES clause of an INSERT statement
Script

30. Write a statement for SQL*Plus that shows the dictionary.
DESC dict;
999999.9999
VALUES
4

31. SQL Developer's ____________________ option allows you to selectively export certain rows and columns.
+
Inconsistencies
X
Export Data

32. SQL Developer provides an extensive list of useful reports and offers the capability to create your own...
User-defined reports
Equijoin and identical column names
Results
SET clause of an UPDATE statement

33. An outer join includes the result rows returned by an __________ plus extra rows where no matches are found.
Non-matching rows
Equijoin
F12
Crow's foot

34. A _____ is a query definition stored in the database that looks just like a table - but does not have any physical rows
X
Three
Any
Parent table

35. What are the main components of a ROWID?
FALSE
UNION
All caps
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.

36. The __________ operator is inclusive of the two values specified.
Retrieve
Scalar
BETWEEN
Committed

37. Oracle uses the outer join operator to indicate that nulls are shown for...
IN ANY ALL SOME
Non-matching rows
MINUS
NATURAL JOIN

38. In SQL Developer field names and table names are shown in the color _______.
Multiple rows
Details
Black
Surrogate key

39. The Nonequijoin can use the ________________ operator to construct joins that are not based on equality of values.
The indexed column is part of an expression. In this case - consider creating a function-based index instead
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
BETWEEN
ADD

40. How many characters can you have using the VARCHAR data type?
4000
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.
The indexed column is part of an expression. In this case - consider creating a function-based index instead
Leading-edge

41. Explain what a static data dictionary view is and how it is used
Fractional seconds
12:00:00 A.M
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.
MINUS

42. List the reasons that a subquery could not be unnested.
X
Asterisk
Script
Month ddth - yyyy

43. The key that most database designers prefer and is chosen by the system is the _____________ key.
Static or dynamic
2000
The indexed column is part of an expression. In this case - consider creating a function-based index instead
Surrogate

44. 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?
DICTIONARY
Re-create
ON
X

45. Explain how you can optimize your queries with subqueries and the main advantage of doing so.
Lists all objects accessible for the chosen database connection. Also lists a helpful dependencies report for accessing change impact.
KEEP INDEX
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
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

46. Returns rows if the condition is true for all the values in the list
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
Twice
All
Orphan

47. A join across three tables can be expressed with the ________ join syntax.
Multiple rows
Dynamic SQL is used to be continuously updated by the background processes in the Oracle instance but never by the user.
Combine
ANSI

48. Write an SQL statement for SQL *Plus in which you want any unique menu items to be displayed from the restaurant table
SELECT DISTINCT menu FROM restaurant
LIKE
Command determines the total number of characters SQL *Plus displays in on line before beginning a new line.
Groups

49. _________ rows are not allowed in the relational model.
Dynamic SQL is used to be continuously updated by the background processes in the Oracle instance but never by the user.
B-Tree Index
Precision
Orphan

50. To place a line comment in your SQL statements - you first place a // at the beginning of the line.
ANY
FALSE
Recursive
99.99