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. Which one of the following string functions tells you how many characters are in a string?
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.
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
Results
LENGTH

2. What does the following function return? SELECT LENGTH(NULL) - FROM dual
When the table is small (unless your business rules require you too)
INNER JOIN
Null
The indexed column is part of an expression. In this case - consider creating a function-based index instead

3. Queries that are found in parentheses are done first - just as in the order of operations when doing...
Mathematical equations
ON
SET clause of an UPDATE statement
DESC dict;

4. SQL*Plus is used more than SQL Developer when you need to...
RENAME - COPY - DROP - TRUNCATE - LOCK - & COMMENT
Run scripts
Hide data
The indexed column is part of an expression. In this case - consider creating a function-based index instead

5. When disabling a unique or primary key - you can keep the index if you specify the __________________ clause in the ALTER TABLE statement.
Month ddth - yyyy
KEEP INDEX
Script
Logical unit of work

6. Subqueries can return...
Three
Multiple rows
Details
LIKE

7. You can simplify the writing of SQL statements by writing SQL _________ that generate and execute other SQL statements.
Orphan
Script
Command determines the total number of characters SQL *Plus displays in on line before beginning a new line.
INTERSECT

8. What is the data type you can use if you need an unlimited number of textual characters?
Self-joins
UNION
INNER JOIN
CLOB

9. Explain how you can optimize your queries with subqueries and the main advantage of doing so.
Asterisk
Retrieve
BETWEEN
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

10. Which operator is most commonly used?
UNION
Results
Actual column
Testing functions

11. List the different types of data dictionary views.
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
A correct statement
USER_ - ALL_ - DBA_ - and V$
When the table is small (unless your business rules require you too)

12. The data type definitions NUMBER(10) and NUMBER(10 -0) are the...
Common column value
Surrogate
Same
Groups

13. To place a line comment in your SQL statements - you first place a // at the beginning of the line.
FALSE
**** 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
Rounded edges

14. What is the command you would type into SQL*Plus if you needed to know the definition for each column of a table?
Structured Query Language
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
DICT_COLUMNS

15. It is considered good form to put all SQL commands in...
All caps
@ or START
RENAME just_two_more_weeks TO finally_i
LIKE

16. To equijoin a table with another table involves matching the...
Nested
ALL_OBJECTS
SUM
Common column value

17. _________ and __________ functions are opposites of each other and provide a value in a group of rows.
COUNT(registration_date) - AVG (capacity) - MIN (capacity) - MAX (capacity)
Both MIN and MAX
Precision
Script

18. Explain the steps needed to run a script in SQL Developer
Any
ALL_OBJECTS
RIGHT LEFT JOIN
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.

19. SQL Developer provides an extensive list of useful reports and offers the capability to create your own...
Month ddth - yyyy
User-defined reports
Precision
Mathematical equations

20. The ______ operator compares a list of values for equivalency
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.
DESC dict;
ANY
All caps

21. The _____________ clause determines how rows are grouped.
DD-MON-YY
LENGTH
Orphan
GROUP BY

22. The ALTER SESSION statement can change the session's...
Self-joins
Any
All caps
Time zone

23. When using the following data: NUMBER(10 -4) - the lowest number you can possibly have is __________.
Parent table
Asterisk
999999.9999
RENAME just_two_more_weeks TO finally_i

24. An outer join includes the result rows returned by an __________ plus extra rows where no matches are found.
BETWEEN
Equijoin
DICT_COLUMNS
Run scripts

25. The time zone displacement value indicates the time difference from _______.
UTC
ON
+
When the table is small (unless your business rules require you too)

26. Explain what is found in the All Objects report folder in SQL Developer
VALUES clause of an INSERT statement
User-defined reports
Both MIN and MAX
Lists all objects accessible for the chosen database connection. Also lists a helpful dependencies report for accessing change impact.

27. When returning multiple rows - a subquery must contain the _____ - _____ - _____ - or ______ operator - otherwise Oracle will return an error
ADD_MONTHS function
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.
IN ANY ALL SOME

28. The ________ operator cannot compare against a list of values.
Fractional seconds
LIKE
4000
Three

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

30. The __________ operator is inclusive of the two values specified.
12:00:00 A.M
Mathematical equations
Default is 14; when you use the default - you repeat the heading every 14 rows.
BETWEEN

31. Another name for a data dictionary view is __________________ or _________________.
Another null
The indexed column is part of an expression. In this case - consider creating a function-based index instead
Static or dynamic
BETWEEN

32. Write a solution that adds 20 minutes to a given date.
INTERSECT
Run scripts
SELECT SYSDATE+1/96 - FROM dual
INNER JOIN

33. You can use the ________________ to subtract months from a given date.
ADD_MONTHS function
Parent table
Retrieve
Crow's foot

34. A join across three tables can be expressed with the ________ join syntax.
ANSI
Export Data
All caps
Command determines the total number of characters SQL *Plus displays in on line before beginning a new line.

35. SELECT * FROM instructor ORDER BY phone
Structured Query Language
A correct statement
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
Surrogate key

36. Write a statement that drops the index need_to_pass_i
DROP INDEX need_to_pass_i
UNION operator
COMMIT
99.99

37. LINESIZE
ADD_MONTHS function
DD-MON-YY
Equijoin
Command determines the total number of characters SQL *Plus displays in on line before beginning a new line.

38. Which format mask displays December 31st - 1999?
Crow's foot
UNION
Multiple rows
Month ddth - yyyy

39. Explain what a static data dictionary view is and how it is used
Static or dynamic
@ or START
Data
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.

40. What is the syntax used to indicate that you are using the Oracle Outer Join operator?
GROUP BY
+
INTERSECT
Equijoin and identical column names

41. Write the syntax to rename index just_two_more_weeks_i to finally_i
USER_ - ALL_ - DBA_ - and V$
FALSE
Correlated
RENAME just_two_more_weeks TO finally_i

42. Explain in detail the impact of INDEXES and how they are used by Oracle.
Three
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
Retrieve
Mathematical equations

43. The ____________ command makes changes permanent.
Columns
Semicolon or forward slash
All caps
COMMIT

44. 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.
Null
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
FALSE
DICT_COLUMNS

45. You use the _________ keyword to add columns or constraints to a table.
Script
Month ddth - yyyy
LIKE
ADD

46. The using clause of the ANSI join syntax always assumes an...
RUN SCRIPT
Actual column
Equijoin and identical column names
KEEP INDEX

47. __________________ inserts the current date and time.
SYSDATE
Command determines the total number of characters SQL *Plus displays in on line before beginning a new line.
BETWEEN
Time zone

48. Instead of using the Oracle Outer Join Operator or the ANSI syntax - you can achieve the same result with two SQL statements: ____________ and a ____________
Implicit conversion
999999.9999
Any
Equijoin and correlated subquery

49. Explain how Substitution Variables are used when writing scripts.
Combine
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.
Primary key/foreign key
CLOB

50. The NEXTVAL and CURRVAL pseudocolumns can be used in which of the following SQL constructs? Select all that apply.
VALUES clause of an INSERT statement
Both MIN and MAX
Any
Black