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. Converting a text literal to DATE format requires the use of the...
BETWEEN
Hide data
RENAME just_two_more_weeks TO finally_i
TO_CHAR function

2. Checks whether any value in the list makes the condition true.
COUNT(registration_date) - AVG (capacity) - MIN (capacity) - MAX (capacity)
X
Any
Results

3. What is the Oracle data dictionary called that contains a set of tables and views containing the data about the database?
Equijoin and identical column names
Fractional seconds
ALL_OBJECTS
12:00:00 A.M

4. _________ rows are not allowed in the relational model.
Primary key/foreign key
Orphan
GROUP BY
MINUS

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

6. 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.
DICTIONARY
VALUES
STORAGE
Data

7. All SQL statements contained within a script must end with a _______________ - even if they are done in SQL Developer.
X
ON
Multiple rows
Semicolon or forward slash

8. When using the following data: NUMBER(10 -4) - the # 10 is called the __________.
Script
FALSE
Precision
12:00:00 A.M

9. The same function can be used ______ in a SELECT statement.
UTC
Twice
User-defined reports
Data

10. The TIMESTAMP WITH LOCAL TIME ZONE data type allows...
Fractional seconds
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.
Equijoin and correlated subquery
Default is 14; when you use the default - you repeat the heading every 14 rows.

11. Write a statement that drops the index need_to_pass_i
MODIFY
Surrogate key
DROP INDEX need_to_pass_i
Twice

12. Subqueries can return...
Primary key/foreign key
Script
Leading-edge
Multiple rows

13. What is Oracle's most popular index storage structure?
Dynamic SQL is used to be continuously updated by the background processes in the Oracle instance but never by the user.
ALL_OBJECTS
B-Tree Index
ANSI

14. ____________ are useful for analyzing and exploring the relationships within your data
X
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
Scale
Self-joins

15. 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.
Details
STORAGE
Business problems
FALSE

16. Write the syntax to rename index just_two_more_weeks_i to finally_i
Implicit conversion
RENAME just_two_more_weeks TO finally_i
Command determines the total number of characters SQL *Plus displays in on line before beginning a new line.
User-defined reports

17. 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.
When the table is small (unless your business rules require you too)
GROUP BY
Has not changed the name
F12

18. Explain how you can optimize your queries with subqueries and the main advantage of doing so.
SYSDATE
Both MIN and MAX
Parent table
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

19. A _____ is a query definition stored in the database that looks just like a table - but does not have any physical rows
Nested
X
Equijoin
BETWEEN

20. The RTRIM function is useful for eliminating ________ in a string.
Details
999999.9999
+
Extra spaces

21. List the steps performed by a correlated subquery.
UTC
SYSDATE
Multiple rows
**** 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

22. The _______ function adds values together for a group of rows.
Export Data
SYSDATE
SUM
Equijoin and correlated subquery

23. What is the name of the key automatically generated from a sequence?
ROLLBACK
Surrogate key
IN ANY ALL SOME
Static or dynamic

24. The _____________ clause determines how rows are grouped.
4000
GROUP BY
Equijoin and identical column names
Optional

25. The ________ operator cannot compare against a list of values.
CLOB
LIKE
UNION
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.

26. When you want to run a script in either SQL*Plus or SQL Developer - you can use a ______ or the _________ command.
@ or START
SUM
Any
Equijoin and correlated subquery

27. Write a statement for SQL*Plus that shows the dictionary.
SET clause of an UPDATE statement
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.
RUN SCRIPT
DESC dict;

28. In SQL Developer field names and table names are shown in the color _______.
ROLLBACK
Black
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
Command determines the total number of characters SQL *Plus displays in on line before beginning a new line.

29. How many characters can be stored in the CHAR column/field?
2000
X
Self-joins
RENAME - COPY - DROP - TRUNCATE - LOCK - & COMMENT

30. What is the first column of a composite index called?
Same
12:00:00 A.M
Leading-edge
When the table is small (unless your business rules require you too)

31. Comparison operators can compare multiple _________________.
Precision
Primary key/foreign key
Columns
Asterisk

32. __________________ inserts the current date and time.
Results
SYSDATE
Location of the file
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

33. ___________ subqueries allow you to reference columns from the outer query and execute the inner query repeatedly
Business problems
COUNT(registration_date) - AVG (capacity) - MIN (capacity) - MAX (capacity)
Correlated
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

34. When you have issued a DELETE command - you can still ________ those rows and restore the information.
Retrieve
Committed
SUM
Recursive

35. Returns rows if the condition is true for all the values in the list
Logical unit of work
All
COUNT(registration_date) - AVG (capacity) - MIN (capacity) - MAX (capacity)
Mathematical equations

36. You can simplify the writing of SQL statements by writing SQL _________ that generate and execute other SQL statements.
Nested
Script
LIKE
Fractional seconds

37. What is the tab in SQL Developer where data dictionary view information can be found?
SUM
Any
Details
Crow's foot

38. SELECT LIST of a subquery in an INSERT statement
Equijoin and identical column names
RIGHT LEFT JOIN
SET clause of an UPDATE statement
Asterisk

39. What does the following function return? SELECT LENGTH(NULL) - FROM dual
MODIFY
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
Null

40. Another name for a data dictionary view is __________________ or _________________.
Default is 14; when you use the default - you repeat the heading every 14 rows.
Crow's foot
Implicit conversion
Static or dynamic

41. The key that most database designers prefer and is chosen by the system is the _____________ key.
Multiple rows
BETWEEN
Surrogate
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

42. List 4 aggregate functions
RENAME just_two_more_weeks TO finally_i
Groups
COUNT(registration_date) - AVG (capacity) - MIN (capacity) - MAX (capacity)
Has not changed the name

43. PAGESIZE
VALUES
Both MIN and MAX
Any
Default is 14; when you use the default - you repeat the heading every 14 rows.

44. The ____________ command makes changes permanent.
COUNT(registration_date) - AVG (capacity) - MIN (capacity) - MAX (capacity)
Dynamic SQL is used to be continuously updated by the background processes in the Oracle instance but never by the user.
Time zone
COMMIT

45. To restart a sequence at a lower number - you can drop and ________ the sequence.
Re-create
Running a script file
Non-matching rows
Committed

46. What is the maximum value for a column defined as NUMBER(4 -2)?
Surrogate
Multiple rows
99.99
Surrogate key

47. The query retrieves more than 5 to 15 percent of the rows
Time zone
The indexed column is part of an expression. In this case - consider creating a function-based index instead
X
F12

48. The using clause of the ANSI join syntax always assumes an...
Equijoin and identical column names
IN ANY ALL SOME
Script
All caps

49. Explain the differences in how an ANSI Full Outer Join and a Full Outer Join using the UNION Operator work
X
Equijoin and identical column names
Any
Mathematical equations

50. When writing the syntax for finding information on three or more tables - the parenthesis around the ON clause is...
Optional
Another null
Inconsistencies
Has not changed the name