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. Instead of using the Oracle Outer Join Operator or the ANSI syntax - you can achieve the same result with two SQL statements: ____________ and a ____________
Asterisk
Equijoin and correlated subquery
Details
Crow's foot

2. Checks whether any value in the list makes the condition true.
Implicit conversion
Surrogate key
Fractional seconds
Any

3. You can simplify the writing of SQL statements by writing SQL _________ that generate and execute other SQL statements.
BETWEEN
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
Self-joins
Script

4. The RTRIM function is useful for eliminating ________ in a string.
Extra spaces
ROLLBACK
Any
Another null

5. Joins involving multiple columns must always follow the ____________ relationship path.
GROUP BY
NATURAL JOIN
Primary key/foreign key
Inconsistencies

6. The Nonequijoin can use the ________________ operator to construct joins that are not based on equality of values.
COUNT(registration_date) - AVG (capacity) - MIN (capacity) - MAX (capacity)
BETWEEN
DD-MON-YY
Actual column

7. When returning multiple rows - a subquery must contain the _____ - _____ - _____ - or ______ operator - otherwise Oracle will return an error
Results
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.
IN ANY ALL SOME
Testing functions

8. The _______ operator determines common rows.
Semicolon or forward slash
INTERSECT
INNER JOIN
DESC dict;

9. Explain how Substitution Variables are used when writing scripts.
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.
VALUES clause of an INSERT 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.
TO_CHAR function

10. A _____ is a query definition stored in the database that looks just like a table - but does not have any physical rows
Another null
Asterisk
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

11. What is the command you would type into SQL*Plus if you needed to know the definition for each column of a table?
Multiple rows
DICT_COLUMNS
VALUES
LIKE

12. Explain how Dynamic SQL is used and give an example of a Dynamic SQL statement.
Three
Dynamic SQL is used to be continuously updated by the background processes in the Oracle instance but never by the user.
All
Run scripts

13. When is it not a good idea to use an index?
Structured Query Language
COUNT(registration_date) - AVG (capacity) - MIN (capacity) - MAX (capacity)
When the table is small (unless your business rules require you too)
IN ANY ALL SOME

14. Checks whether any value in the list makes the condition true.
Nested
4
ANSI
Any

15. The ALTER SESSION statement can change the session's...
Precision
Equijoin and correlated subquery
DICTIONARY
Time zone

16. What is the syntax used to indicate that you are using the Oracle Outer Join operator?
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
Semicolon or forward slash
+

17. What does the following function return? SELECT LENGTH(NULL) - FROM dual
Actual column
Inconsistencies
Null
X

18. Self-joins are useful for performing comparisons and checking for ___________ in data.
Run scripts
Surrogate
Re-create
Inconsistencies

19. The time zone displacement value indicates the time difference from _______.
UTC
Logical unit of work
Testing functions
Running a script file

20. The term ____________ ___________ is used to express a join that satisfies the join condition.
INNER JOIN
Command returns the number of records returned by a query.
Self-joins
Lists all objects accessible for the chosen database connection. Also lists a helpful dependencies report for accessing change impact.

21. _________________ relationships are always optional relationships.
Twice
Has not changed the name
Common column value
Recursive

22. The _____________ clause determines how rows are grouped.
Groups
Scale
GROUP BY
Scalar

23. Explain the differences in how an ANSI Full Outer Join and a Full Outer Join using the UNION Operator work
When the table is small (unless your business rules require you too)
Leading-edge
X
Re-create

24. List the steps performed by a correlated subquery.
TO_CHAR function
B-Tree Index
**** 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
Both MIN and MAX

25. You can pass parameters from the operating system when ___________ in SQl*Plus
Running a script file
Time zone
Business problems
Any

26. Subqueries can return...
INTERSECT
INNER JOIN
X
Multiple rows

27. What is the main difference between the NOT EXISTS and the NOT IN operators?
UNION operator
The way NULL values are treated
4
Multiple rows

28. _________ rows are not allowed in the relational model.
Results
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.
Orphan
A correct statement

29. You use the __________ keyword to change characteristics of a column.
ANY
Rounded edges
MODIFY
Surrogate

30. SELECT LIST of a subquery in an INSERT statement
All
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
Extra spaces
SET clause of an UPDATE statement

31. The _______ function adds values together for a group of rows.
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
Details
SUM
Non-matching rows

32. The focus of the logical data model is _____________
Hide data
Primary key/foreign key
DD-MON-YY
Business problems

33. Which format mask displays December 31st - 1999?
Equijoin
Month ddth - yyyy
SELECT DISTINCT menu FROM restaurant
COUNT(registration_date) - AVG (capacity) - MIN (capacity) - MAX (capacity)

34. Returns rows if the condition is true for all the values in the list
All
Results
SELECT SYSDATE+1/96 - FROM dual
Committed

35. Write a solution that adds 20 minutes to a given date.
2000
SELECT SYSDATE+1/96 - FROM dual
Common column value
SET clause of an UPDATE statement

36. The ___________ operator tests whether a matching row cannot be found.
Surrogate
VALUES
X
LENGTH

37. The data type definitions NUMBER(10) and NUMBER(10 -0) are the...
Testing functions
Same
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.
Hide data

38. The key that most database designers prefer and is chosen by the system is the _____________ key.
Three
Surrogate
RENAME - COPY - DROP - TRUNCATE - LOCK - & COMMENT
Another null

39. The ____________ keywords and the USING clause of the ANSI join syntax are mutually exclusive.
NATURAL JOIN
Static or dynamic
X
Recursive

40. When using the following data: NUMBER(10 -4) - the # 4 is called the __________.
Scale
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.
Committed
Recursive

41. The TIMESTAMP WITH LOCAL TIME ZONE data type allows...
Fractional seconds
Data
Inconsistencies
User-defined reports

42. Write a statement that drops the index need_to_pass_i
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.
BETWEEN
Precision
DROP INDEX need_to_pass_i

43. To place a line comment in your SQL statements - you first place a // at the beginning of the line.
FALSE
RENAME just_two_more_weeks TO finally_i
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.
INTERSECT

44. ___________ subqueries allow you to reference columns from the outer query and execute the inner query repeatedly
INTERSECT
Correlated
Implicit conversion
X

45. __________________ inserts the current date and time.
@ or START
Fractional seconds
Data
SYSDATE

46. Write the syntax to rename index just_two_more_weeks_i to finally_i
A correct statement
INNER JOIN
RENAME just_two_more_weeks TO finally_i
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.

47. When writing the syntax for finding information on three or more tables - the parenthesis around the ON clause is...
RENAME just_two_more_weeks TO finally_i
Fractional seconds
Optional
A correct statement

48. 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.
Has not changed the name
Semicolon or forward slash
V$
Another null

49. If a graphical representation of a table's box has __________ it means that the relationship is identifying.
Rounded edges
99.99
RIGHT LEFT JOIN
Asterisk

50. Another name for a data dictionary view is __________________ or _________________.
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
RIGHT LEFT JOIN
Static or dynamic
Surrogate