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. You use the __________ keyword to change characteristics of a column.
V$
INNER JOIN
B-Tree Index
MODIFY

2. An outer join includes the result rows returned by an __________ plus extra rows where no matches are found.
Equijoin
Rounded edges
SYSDATE
SET clause of an UPDATE statement

3. Explain the steps needed to run a script in SQL Developer
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.
Results
X
Data

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

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5. The ____________ command makes changes permanent.
COMMIT
Month ddth - yyyy
V$
+

6. How many characters can be stored in the CHAR column/field?
2000
Has not changed the name
Committed
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.

7. List the steps performed by a correlated subquery.
**** 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
Dynamic SQL is used to be continuously updated by the background processes in the Oracle instance but never by the user.
BETWEEN
Recursive

8. The query retrieves more than 5 to 15 percent of the rows
The indexed column is part of an expression. In this case - consider creating a function-based index instead
Scale
2000
UNION

9. When disabling a unique or primary key - you can keep the index if you specify the __________________ clause in the ALTER TABLE statement.
When the table is small (unless your business rules require you too)
KEEP INDEX
Asterisk
Export Data

10. Which operator is most commonly used?
RENAME just_two_more_weeks TO finally_i
Combine
IN ANY ALL SOME
UNION

11. Comparison operators can compare multiple _________________.
Multiple rows
Columns
Combine
Precision

12. What is the first column of a composite index called?
Optional
Leading-edge
Structured Query Language
Mathematical equations

13. UNION ALL does not sort - therefore it is less time consuming to use than the...
ROLLBACK
UNION operator
Any
Columns

14. The using clause of the ANSI join syntax always assumes an...
LENGTH
STORAGE
Details
Equijoin and identical column names

15. What is the keyboard shortcut for the ROLLBACK command?
F12
VALUES
Static or dynamic
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.

16. What are the main components of a ROWID?
UNION operator
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.
Self-joins
MINUS

17. Write a statement for SQL*Plus that shows the dictionary.
SELECT SYSDATE+1/96 - FROM dual
DICTIONARY
Black
DESC dict;

18. Write a statement that drops the index need_to_pass_i
Static or dynamic
COMMIT
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
DROP INDEX need_to_pass_i

19. List 4 aggregate functions
COMMIT
Implicit conversion
COUNT(registration_date) - AVG (capacity) - MIN (capacity) - MAX (capacity)
Extra spaces

20. To equijoin a table with another table involves matching the...
Optional
Common column value
B-Tree Index
NATURAL JOIN

21. The COUNT function uses the __________ wildcard.
Asterisk
Scale
Equijoin and correlated subquery
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.

22. _________________ relationships are always optional relationships.
A correct statement
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
Recursive
VALUES clause of an INSERT statement

23. Explain what a static data dictionary view is and how it is used
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.
Retrieve
A correct statement
KEEP INDEX

24. The ____________ clause on a CREATE TABLE statement can specify how much space to allocate.
VALUES clause of an INSERT statement
STORAGE
12:00:00 A.M
Default is 14; when you use the default - you repeat the heading every 14 rows.

25. When column names on the tables are different - you use the ______ condition.
F12
Fractional seconds
Results
ON

26. PAGESIZE
Re-create
LENGTH
Columns
Default is 14; when you use the default - you repeat the heading every 14 rows.

27. The _______ function adds values together for a group of rows.
INTERSECT
SUM
When the table is small (unless your business rules require you too)
Asterisk

28. The same function can be used ______ in a SELECT statement.
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
Twice
Another null
Testing functions

29. Explain how Substitution Variables are used when writing scripts.
ROLLBACK
Default is 14; when you use the default - you repeat the heading every 14 rows.
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.
Any

30. List the reasons that a subquery could not be unnested.
IN ANY ALL SOME
Asterisk
B-Tree Index
X

31. Checks whether any value in the list makes the condition true.
All caps
RENAME - COPY - DROP - TRUNCATE - LOCK - & COMMENT
Scalar
Any

32. The DUAL table can be used for...
Three
Logical unit of work
DECODE
Testing functions

33. Write an SQL statement for SQL *Plus in which you want any unique menu items to be displayed from the restaurant table
Rounded edges
Month ddth - yyyy
SELECT DISTINCT menu FROM restaurant
Command returns the number of records returned by a query.

34. Which format mask displays December 31st - 1999?
USER_ - ALL_ - DBA_ - and V$
@ or START
Dynamic SQL is used to be continuously updated by the background processes in the Oracle instance but never by the user.
Month ddth - yyyy

35. Explain how Oracle treats locks when a database is being updated and needs to be viewed by other users.
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
Nested
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
RENAME - COPY - DROP - TRUNCATE - LOCK - & COMMENT

36. Dynamic views begin with a ___________.
V$
Scale
Rounded edges
Hide data

37. What is the Oracle data dictionary called that contains a set of tables and views containing the data about the database?
ALL_OBJECTS
INNER JOIN
Control - Revoke - Define - TRUNCATE Manipulate - MERGE
COUNT(registration_date) - AVG (capacity) - MIN (capacity) - MAX (capacity)

38. What is the main difference between the NOT EXISTS and the NOT IN operators?
Rounded edges
Nested
4000
The way NULL values are treated

39. The ___________ operator tests whether a matching row cannot be found.
Any
Mathematical equations
X
Control - Revoke - Define - TRUNCATE Manipulate - MERGE

40. When writing an ANSI outer join - the keywords _________ OUTER and _________ OUTER are added to the __________ keyword to indicate the rows from which table to use.
+
RIGHT LEFT JOIN
DECODE
Columns

41. When using the following data: NUMBER(10 -4) - the lowest number you can possibly have is __________.
4000
Static or dynamic
COMMIT
999999.9999

42. What is the syntax used to indicate that you are using the Oracle Outer Join operator?
+
Lists all objects accessible for the chosen database connection. Also lists a helpful dependencies report for accessing change impact.
UTC
Running a script file

43. The ________________ is a type of statement whereby you retrieve data that exists in one table - but not in another.
ANSI
MINUS
Black
Orphan

44. What is the name of the view where you can find the collection of static and data dictionary tables and views - along with their descriptions?
DICTIONARY
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
Another null
IN ANY ALL SOME

45. Subqueries can return...
Hide data
SET clause of an UPDATE statement
Multiple rows
Nested

46. Explain why constraints are used when building tables.

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47. The ROWID pseudocolumn is not an ________- but it acts like one.
GROUP BY
SUM
Any
Actual column

48. List 6 Table-Related Menu Choices
Command returns the number of records returned by a query.
Extra spaces
SUM
RENAME - COPY - DROP - TRUNCATE - LOCK - & COMMENT

49. Explain how the SPOOL command is used and what program it can be used in.
Precision
ANY
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
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.

50. Another name for a data dictionary view is __________________ or _________________.
Mathematical equations
Static or dynamic
V$
FALSE