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.
Dynamic SQL is used to be continuously updated by the background processes in the Oracle instance but never by the user.
Run scripts
Three
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

2. In a view you can give a column a different name than it has in the...
Asterisk
@ or START
999999.9999
Parent table

3. An outer join includes the result rows returned by an __________ plus extra rows where no matches are found.
V$
Equijoin
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
Combine

4. To restart a sequence at a lower number - you can drop and ________ the sequence.
SYSDATE
Re-create
Combine
RENAME - COPY - DROP - TRUNCATE - LOCK - & COMMENT

5. The DUAL table can be used for...
4
UTC
Testing functions
RIGHT LEFT JOIN

6. Which operator is most commonly used?
Business problems
Surrogate key
ANY
UNION

7. SQL Developer's ____________________ option allows you to selectively export certain rows and columns.
Scale
VALUES
Export Data
RIGHT LEFT JOIN

8. Queries that are found in parentheses are done first - just as in the order of operations when doing...
99.99
Hide data
Static or dynamic
Mathematical equations

9. The NEXTVAL and CURRVAL pseudocolumns can be used in which of the following SQL constructs? Select all that apply.
Committed
F12
Fractional seconds
VALUES clause of an INSERT statement

10. Checks whether any value in the list makes the condition true.
All caps
Any
DECODE
RENAME just_two_more_weeks TO finally_i

11. FEEDBACK
Run scripts
99.99
Command returns the number of records returned by a query.
Surrogate key

12. The key that most database designers prefer and is chosen by the system is the _____________ key.
Surrogate
COUNT(registration_date) - AVG (capacity) - MIN (capacity) - MAX (capacity)
Optional
@ or START

13. NUMBER functions can be...
Self-joins
COUNT(registration_date) - AVG (capacity) - MIN (capacity) - MAX (capacity)
Nested
SUM

14. What is the data type you can use if you need an unlimited number of textual characters?
Both MIN and MAX
CLOB
ROLLBACK
INNER JOIN

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

16. Write a statement for SQL*Plus that shows the dictionary.
DESC dict;
Export Data
Logical unit of work
RENAME - COPY - DROP - TRUNCATE - LOCK - & COMMENT

17. SQL Developer provides an extensive list of useful reports and offers the capability to create your own...
User-defined reports
Self-joins
Command determines the total number of characters SQL *Plus displays in on line before beginning a new line.
UNION

18. You use the __________ keyword to change characteristics of a column.
Crow's foot
Testing functions
MODIFY
4

19. Which format mask displays December 31st - 1999?
V$
DICT_COLUMNS
Month ddth - yyyy
DESC dict;

20. If a graphical representation of a table's box has __________ it means that the relationship is identifying.
DECODE
UTC
Equijoin
Rounded edges

21. How many characters can be stored in the CHAR column/field?
INTERSECT
2000
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.
COUNT(registration_date) - AVG (capacity) - MIN (capacity) - MAX (capacity)

22. The _______ function adds values together for a group of rows.
Surrogate key
SUM
DD-MON-YY
SELECT SYSDATE+1/96 - FROM dual

23. Self-joins are useful for performing comparisons and checking for ___________ in data.
Inconsistencies
X
User-defined reports
Extra spaces

24. List the steps performed by a correlated subquery.
Any
USER_ - ALL_ - DBA_ - and V$
**** 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
Scale

25. Explain how Dynamic SQL is used and give an example of a Dynamic SQL statement.
UNION operator
ADD
Dynamic SQL is used to be continuously updated by the background processes in the Oracle instance but never by the user.
Actual column

26. All SQL statements contained within a script must end with a _______________ - even if they are done in SQL Developer.
Semicolon or forward slash
SET clause of an UPDATE statement
Orphan
DROP INDEX need_to_pass_i

27. LINESIZE
MINUS
Mathematical equations
Default is 14; when you use the default - you repeat the heading every 14 rows.
Command determines the total number of characters SQL *Plus displays in on line before beginning a new line.

28. What is the keyboard shortcut for the ROLLBACK command?
Groups
Non-matching rows
F12
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.

29. UNION ALL does not sort - therefore it is less time consuming to use than the...
COUNT(registration_date) - AVG (capacity) - MIN (capacity) - MAX (capacity)
Orphan
UNION operator
+

30. ____________ are useful for analyzing and exploring the relationships within your data
RUN SCRIPT
Self-joins
Logical unit of work
Combine

31. The ____________ clause on a CREATE TABLE statement can specify how much space to allocate.
2000
Equijoin
STORAGE
ANY

32. _________ and __________ functions are opposites of each other and provide a value in a group of rows.
Both MIN and MAX
Command determines the total number of characters SQL *Plus displays in on line before beginning a new line.
TO_CHAR function
Parent table

33. Joins involving multiple columns must always follow the ____________ relationship path.
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
4
Primary key/foreign key
Orphan

34. Instead of using the Oracle Outer Join Operator or the ANSI syntax - you can achieve the same result with two SQL statements: ____________ and a ____________
BETWEEN
Equijoin and correlated subquery
BETWEEN
Multiple rows

35. The COUNT function uses the __________ wildcard.
RUN SCRIPT
MINUS
**** 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
Asterisk

36. When using the following data: NUMBER(10 -4) - the # 4 is called the __________.
Scale
Common column value
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
Testing functions

37. Explain how Substitution Variables are used when writing scripts.
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.
Self-joins
A correct statement
UTC

38. To place a line comment in your SQL statements - you first place a // at the beginning of the line.
DROP INDEX need_to_pass_i
FALSE
RUN SCRIPT
MODIFY

39. A transaction is a...
COUNT(registration_date) - AVG (capacity) - MIN (capacity) - MAX (capacity)
SELECT SYSDATE+1/96 - FROM dual
Logical unit of work
MINUS

40. When is it not a good idea to use an index?
Non-matching rows
When the table is small (unless your business rules require you too)
DROP INDEX need_to_pass_i
Three

41. What is Oracle's most popular index storage structure?
B-Tree Index
2000
RIGHT LEFT JOIN
UNION operator

42. When returning multiple rows - a subquery must contain the _____ - _____ - _____ - or ______ operator - otherwise Oracle will return an error
GROUP BY
Results
Hide data
IN ANY ALL SOME

43. A _____ is a query definition stored in the database that looks just like a table - but does not have any physical rows
Scalar
GROUP BY
X
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.

44. What is the maximum value for a column defined as NUMBER(4 -2)?
999999.9999
UNION operator
99.99
TO_CHAR function

45. What is the first column of a composite index called?
MINUS
FALSE
Business problems
Leading-edge

46. List 4 aggregate functions
Any
Common column value
Black
COUNT(registration_date) - AVG (capacity) - MIN (capacity) - MAX (capacity)

47. Match each of the SQL commands on the left with a verb from the list.
Control - Revoke - Define - TRUNCATE Manipulate - MERGE
The indexed column is part of an expression. In this case - consider creating a function-based index instead
Actual column
DICTIONARY

48. You can use the ________________ to subtract months from a given date.
ADD_MONTHS function
Three
RENAME just_two_more_weeks TO finally_i
Primary key/foreign key

49. The ___________ operator tests whether a matching row cannot be found.
Scale
RUN SCRIPT
X
CLOB

50. You can simplify the writing of SQL statements by writing SQL _________ that generate and execute other SQL statements.
Same
GROUP BY
Script
COMMIT