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. The ALTER SESSION statement can change the session's...
Logical unit of work
Time zone
Both MIN and MAX
DECODE

2. What are the main components of a ROWID?
The way NULL values are treated
SELECT SYSDATE+1/96 - FROM dual
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.

3. PAGESIZE
Default is 14; when you use the default - you repeat the heading every 14 rows.
User-defined reports
Implicit conversion
Logical unit of work

4. To revert back to a state that happened before you ran your change statement - you issue a ____________ command.
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.
Columns
Correlated
ROLLBACK

5. What is the name of the key automatically generated from a sequence?
Correlated
ADD
LIKE
Surrogate key

6. The Nonequijoin can use the ________________ operator to construct joins that are not based on equality of values.
BETWEEN
Twice
Precision
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

7. What is the tab in SQL Developer where data dictionary view information can be found?
Details
SELECT DISTINCT menu FROM restaurant
Surrogate key
DECODE

8. The ROWID pseudocolumn is not an ________- but it acts like one.
Leading-edge
BETWEEN
Actual column
Dynamic SQL is used to be continuously updated by the background processes in the Oracle instance but never by the user.

9. 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.
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.
DD-MON-YY
Leading-edge
RIGHT LEFT JOIN

10. Write a statement that drops the index need_to_pass_i
4
V$
Logical unit of work
DROP INDEX need_to_pass_i

11. The _______ function adds values together for a group of rows.
Multiple rows
IN ANY ALL SOME
SUM
Re-create

12. The ____________ command makes changes permanent.
DICTIONARY
Primary key/foreign key
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
COMMIT

13. Checks whether any value in the list makes the condition true.
Surrogate key
Any
MODIFY
When the table is small (unless your business rules require you too)

14. The key that most database designers prefer and is chosen by the system is the _____________ key.
Control - Revoke - Define - TRUNCATE Manipulate - MERGE
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.
Surrogate
Logical unit of work

15. 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.
4000
SELECT SYSDATE+1/96 - FROM dual
Running a script file
FALSE

16. UNION ALL does not sort - therefore it is less time consuming to use than the...
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
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.
UNION operator
MODIFY

17. Comparison operators can compare multiple _________________.
RIGHT LEFT JOIN
UNION operator
Columns
Asterisk

18. Explicit data type conversion is preferable to Oracle's...
Another null
X
Fractional seconds
Implicit conversion

19. The same function can be used ______ in a SELECT statement.
VALUES clause of an INSERT statement
Crow's foot
Time zone
Twice

20. The ____________ keywords and the USING clause of the ANSI join syntax are mutually exclusive.
All
Equijoin
Both MIN and MAX
NATURAL JOIN

21. In a view you can give a column a different name than it has in the...
Another null
FALSE
DICT_COLUMNS
Parent table

22. When using the data NUMBER(10 -4) there will be _______ digits following the decimal point.
Run scripts
DECODE
Command determines the total number of characters SQL *Plus displays in on line before beginning a new line.
4

23. List the reasons that a subquery could not be unnested.
Equijoin and correlated subquery
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.
X
TO_CHAR function

24. Subqueries can return...
Export Data
Multiple rows
LENGTH
Details

25. A _____ is a query definition stored in the database that looks just like a table - but does not have any physical rows
X
Re-create
Mathematical equations
4000

26. The _______ operator determines common rows.
Run scripts
BETWEEN
DECODE
INTERSECT

27. List 6 Table-Related Menu Choices
Null
SELECT SYSDATE+1/96 - FROM dual
Structured Query Language
RENAME - COPY - DROP - TRUNCATE - LOCK - & COMMENT

28. Oracle uses the outer join operator to indicate that nulls are shown for...
Business problems
Non-matching rows
Orphan
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.

29. When you want to run a script in either SQL*Plus or SQL Developer - you can use a ______ or the _________ command.
Time zone
@ or START
Optional
Run scripts

30. What is the first column of a composite index called?
RUN SCRIPT
DECODE
ROLLBACK
Leading-edge

31. A transaction is a...
Logical unit of work
RENAME - COPY - DROP - TRUNCATE - LOCK - & COMMENT
Any
Recursive

32. When is it not a good idea to use an index?
Surrogate key
UTC
Any
When the table is small (unless your business rules require you too)

33. A _________ subquery returns a single column with a single row
Multiple rows
LENGTH
99.99
Scalar

34. The ____________ clause on a CREATE TABLE statement can specify how much space to allocate.
COMMIT
99.99
STORAGE
COUNT(registration_date) - AVG (capacity) - MIN (capacity) - MAX (capacity)

35. List 4 aggregate functions
SET clause of an UPDATE statement
ROLLBACK
VALUES
COUNT(registration_date) - AVG (capacity) - MIN (capacity) - MAX (capacity)

36. Which operator is most commonly used?
Equijoin and correlated subquery
UNION
Has not changed the name
MODIFY

37. List the steps performed by a correlated subquery.
ADD
Rounded edges
**** 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
Any

38. 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.
Nested
DD-MON-YY
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
Has not changed the name

39. An outer join includes the result rows returned by an __________ plus extra rows where no matches are found.
ROLLBACK
Equijoin
Committed
+

40. The TRUNC function on a date without a format model truncates the timestamp to...
User-defined reports
12:00:00 A.M
DICTIONARY
F12

41. Queries that are found in parentheses are done first - just as in the order of operations when doing...
Mathematical equations
DICT_COLUMNS
SELECT DISTINCT menu FROM restaurant
BETWEEN

42. The RTRIM function is useful for eliminating ________ in a string.
Structured Query Language
MINUS
Extra spaces
All

43. You use the __________ keyword to change characteristics of a column.
SYSDATE
X
ON
MODIFY

44. You can __________ DISTINCT and a GROUP BY clause in the same SELECT statement.
4000
Combine
RIGHT LEFT JOIN
BETWEEN

45. FEEDBACK
Command returns the number of records returned by a query.
RENAME - COPY - DROP - TRUNCATE - LOCK - & COMMENT
Run scripts
F12

46. ____________ are useful for analyzing and exploring the relationships within your data
Export Data
DESC dict;
Self-joins
Location of the file

47. SQL Developer provides an extensive list of useful reports and offers the capability to create your own...
4000
User-defined reports
SET clause of an UPDATE statement
Re-create

48. To equijoin a table with another table involves matching the...
Common column value
FALSE
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
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

49. Converting a text literal to DATE format requires the use of the...
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
TO_CHAR function

50. SQL*Plus is used more than SQL Developer when you need to...
The indexed column is part of an expression. In this case - consider creating a function-based index instead
GROUP BY
Run scripts
KEEP INDEX