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. To join four tables - you must have at least _____ join conditions.
Location of the file
Another null
Three
Command returns the number of records returned by a query.

2. Write the syntax to rename index just_two_more_weeks_i to finally_i
Time zone
RENAME just_two_more_weeks TO finally_i
Black
Month ddth - yyyy

3. When you want to run a script in either SQL*Plus or SQL Developer - you can use a ______ or the _________ command.
MINUS
@ or START
DROP INDEX need_to_pass_i
Lists all objects accessible for the chosen database connection. Also lists a helpful dependencies report for accessing change impact.

4. UNION ALL does not sort - therefore it is less time consuming to use than the...
Retrieve
Black
@ or START
UNION operator

5. Write a statement that drops the index need_to_pass_i
Asterisk
Logical unit of work
DROP INDEX need_to_pass_i
Combine

6. Returns rows if the condition is true for all the values in the list
X
RIGHT LEFT JOIN
All
Committed

7. SELECT * FROM instructor ORDER BY phone
Columns
A correct statement
LIKE
ADD

8. All SQL statements contained within a script must end with a _______________ - even if they are done in SQL Developer.
Semicolon or forward slash
VALUES
X
BETWEEN

9. When using the data NUMBER(10 -4) there will be _______ digits following the decimal point.
4
Null
BETWEEN
TO_CHAR function

10. _________ rows are not allowed in the relational model.
DD-MON-YY
Orphan
RUN SCRIPT
UNION operator

11. To restart a sequence at a lower number - you can drop and ________ the sequence.
When the table is small (unless your business rules require you too)
X
SUM
Re-create

12. The ________________ is a type of statement whereby you retrieve data that exists in one table - but not in another.
RENAME just_two_more_weeks TO finally_i
Surrogate
Semicolon or forward slash
MINUS

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

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14. How many characters can you have using the VARCHAR data type?
4000
SELECT SYSDATE+1/96 - FROM dual
Command determines the total number of characters SQL *Plus displays in on line before beginning a new line.
A correct statement

15. What is the data type you can use if you need an unlimited number of textual characters?
STORAGE
@ or START
DD-MON-YY
CLOB

16. It is considered good form to put all SQL commands in...
Structured Query Language
All caps
Committed
CLOB

17. You can __________ DISTINCT and a GROUP BY clause in the same SELECT statement.
DICT_COLUMNS
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.
Combine
RENAME just_two_more_weeks TO finally_i

18. The _______ operator determines common rows.
SUM
IN ANY ALL SOME
INTERSECT
LENGTH

19. When using the following data: NUMBER(10 -4) - the # 10 is called the __________.
DECODE
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
Precision
Both MIN and MAX

20. Explain the differences in how an ANSI Full Outer Join and a Full Outer Join using the UNION Operator work
GROUP BY
+
DICTIONARY
X

21. If a graphical representation of a table's box has __________ it means that the relationship is identifying.
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
Rounded edges
Committed
Actual column

22. The key that most database designers prefer and is chosen by the system is the _____________ key.
Lists all objects accessible for the chosen database connection. Also lists a helpful dependencies report for accessing change impact.
Combine
Surrogate
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

23. What is the command you would type into SQL*Plus if you needed to know the definition for each column of a table?
Command returns the number of records returned by a query.
ALL_OBJECTS
DICT_COLUMNS
Structured Query Language

24. The ____________ icon allows you to execute multiple statements and emulates SQL *Plus as much as possible.
RENAME just_two_more_weeks TO finally_i
RUN SCRIPT
Surrogate
Control - Revoke - Define - TRUNCATE Manipulate - MERGE

25. When you run a script in SQL*Plus you must give the...
Location of the file
Running a script file
4000
Surrogate

26. The ________ operator cannot compare against a list of values.
Primary key/foreign key
Command returns the number of records returned by a query.
Self-joins
LIKE

27. Explain how Substitution Variables are used when writing scripts.
LENGTH
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.
KEEP INDEX

28. What is the first column of a composite index called?
Fractional seconds
Twice
DD-MON-YY
Leading-edge

29. A _________ subquery returns a single column with a single row
Export Data
GROUP BY
Scalar
Leading-edge

30. When using the following data: NUMBER(10 -4) - the lowest number you can possibly have is __________.
DECODE
999999.9999
Equijoin and correlated subquery
SUM

31. The _____________ clause determines how rows are grouped.
Any
GROUP BY
@ or START
Run scripts

32. Which one of the following string functions tells you how many characters are in a string?
LENGTH
ROLLBACK
Structured Query Language
ADD

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

34. List the different types of data dictionary views.
TO_CHAR function
USER_ - ALL_ - DBA_ - and V$
Inconsistencies
COUNT(registration_date) - AVG (capacity) - MIN (capacity) - MAX (capacity)

35. The TIMESTAMP WITH LOCAL TIME ZONE data type allows...
Fractional seconds
BETWEEN
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.
DD-MON-YY

36. What is Oracle's most popular index storage structure?
Retrieve
The indexed column is part of an expression. In this case - consider creating a function-based index instead
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
B-Tree Index

37. 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.
Export Data
Logical unit of work
Black

38. What is the most common DATE format found in SQL?
TO_CHAR function
UNION
DD-MON-YY
SELECT DISTINCT menu FROM restaurant

39. To revert back to a state that happened before you ran your change statement - you issue a ____________ command.
Hide data
ON
Dynamic SQL is used to be continuously updated by the background processes in the Oracle instance but never by the user.
ROLLBACK

40. What is the main difference between the NOT EXISTS and the NOT IN operators?
SUM
ANY
The way NULL values are treated
SET clause of an UPDATE statement

41. 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
Running a script file
Rounded edges
Equijoin and correlated subquery

42. The time zone displacement value indicates the time difference from _______.
UTC
Month ddth - yyyy
Results
Leading-edge

43. 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
X
DECODE
DESC dict;

44. Users can only see changes made to a database once they have been...
Surrogate
Committed
Non-matching rows
MINUS

45. 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.
When the table is small (unless your business rules require you too)
Asterisk
FALSE
Equijoin

46. NUMBER functions can be...
Nested
The indexed column is part of an expression. In this case - consider creating a function-based index instead
99.99
2000

47. You can use the ________________ to subtract months from a given date.
Twice
Same
2000
ADD_MONTHS function

48. List the reasons that a subquery could not be unnested.
X
Black
Scale
Nested

49. Explicit data type conversion is preferable to Oracle's...
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.
User-defined reports
X
Implicit conversion

50. The focus of the logical data model is _____________
ADD
F12
STORAGE
Business problems