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. When is it not a good idea to use an index?
GROUP BY
Command determines the total number of characters SQL *Plus displays in on line before beginning a new line.
Run scripts
When the table is small (unless your business rules require you too)

2. What is the command you would type into SQL*Plus if you needed to know the definition for each column of a table?
DICT_COLUMNS
Recursive
Black
Command determines the total number of characters SQL *Plus displays in on line before beginning a new line.

3. Instead of using the Oracle Outer Join Operator or the ANSI syntax - you can achieve the same result with two SQL statements: ____________ and a ____________
X
ADD_MONTHS function
Crow's foot
Equijoin and correlated subquery

4. You can pass parameters from the operating system when ___________ in SQl*Plus
Extra spaces
Running a script file
Hide data
Re-create

5. It is considered good form to put all SQL commands in...
Surrogate
Script
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.
All caps

6. Write the syntax to rename index just_two_more_weeks_i to finally_i
USER_ - ALL_ - DBA_ - and V$
RENAME just_two_more_weeks TO finally_i
Same
Equijoin

7. The ___________ operator tests whether a matching row cannot be found.
When the table is small (unless your business rules require you too)
Command determines the total number of characters SQL *Plus displays in on line before beginning a new line.
X
Mathematical equations

8. The time zone displacement value indicates the time difference from _______.
Lists all objects accessible for the chosen database connection. Also lists a helpful dependencies report for accessing change impact.
UTC
Both MIN and MAX
STORAGE

9. Checks whether any value in the list makes the condition true.
LIKE
Black
Logical unit of work
Any

10. An outer join includes the result rows returned by an __________ plus extra rows where no matches are found.
Multiple rows
FALSE
Equijoin
Retrieve

11. List the reasons that a subquery could not be unnested.
Business problems
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
X
Time zone

12. When using the following data: NUMBER(10 -4) - the # 4 is called the __________.
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.
Scalar
Extra spaces
Scale

13. A _____ is a query definition stored in the database that looks just like a table - but does not have any physical rows
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.
X
ON
Run scripts

14. _________________ relationships are always optional relationships.
Recursive
Null
Another null
Hide data

15. What is the keyboard shortcut for the ROLLBACK command?
99.99
Rounded edges
F12
Re-create

16. The same function can be used ______ in a SELECT statement.
Twice
Columns
Groups
Same

17. To join four tables - you must have at least _____ join conditions.
Twice
Black
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
Three

18. Write an SQL statement for SQL *Plus in which you want any unique menu items to be displayed from the restaurant table
SELECT DISTINCT menu FROM restaurant
Control - Revoke - Define - TRUNCATE Manipulate - MERGE
SUM
Script

19. Explain how the SPOOL command is used and what program it can be used in.
SELECT DISTINCT menu FROM restaurant
Mathematical equations
Equijoin and identical column names
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

20. The ALTER SESSION statement can change the session's...
Semicolon or forward slash
+
Time zone
Null

21. 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
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
FALSE
Parent table

22. If a graphical representation of a table's box has __________ it means that the relationship is identifying.
@ or START
Equijoin and correlated subquery
Rounded edges
Results

23. What is the name of the key automatically generated from a sequence?
Surrogate key
Asterisk
Actual column
LENGTH

24. The ____________ clause on a CREATE TABLE statement can specify how much space to allocate.
SELECT SYSDATE+1/96 - FROM dual
Leading-edge
STORAGE
Correlated

25. Match each of the SQL commands on the left with a verb from the list.
Control - Revoke - Define - TRUNCATE Manipulate - MERGE
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
Same
KEEP INDEX

26. The ________________ is a type of statement whereby you retrieve data that exists in one table - but not in another.
All
Fractional seconds
MINUS
SYSDATE

27. You use the __________ keyword to change characteristics of a column.
KEEP INDEX
Fractional seconds
MODIFY
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

28. The _______ function lets you perform if-then-else functionality with the SQL language.
DECODE
@ or START
A correct statement
Details

29. You can use the ________________ to subtract months from a given date.
ADD_MONTHS function
Multiple rows
Month ddth - yyyy
Equijoin and correlated subquery

30. Queries that are found in parentheses are done first - just as in the order of operations when doing...
Scale
ANSI
Mathematical equations
2000

31. Explain how you can optimize your queries with subqueries and the main advantage of doing so.
Primary key/foreign key
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
Any
Hide data

32. 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 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.
RIGHT LEFT JOIN
Parent table
Twice

33. SQL Developer provides an extensive list of useful reports and offers the capability to create your own...
DICT_COLUMNS
User-defined reports
MODIFY
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.

34. Comparison operators can compare multiple _________________.
Columns
SUM
When the table is small (unless your business rules require you too)
Semicolon or forward slash

35. ____________ are useful for analyzing and exploring the relationships within your data
Default is 14; when you use the default - you repeat the heading every 14 rows.
Inconsistencies
Optional
Self-joins

36. NUMBER functions can be...
ANY
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.
Script
Nested

37. The COUNT function is useful for determining whether a table has...
Data
Multiple rows
Precision
Common column value

38. Explain how Substitution Variables are used when writing scripts.
Has not changed the name
Crow's foot
STORAGE
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.

39. The ____________ keywords and the USING clause of the ANSI join syntax are mutually exclusive.
Data
SET clause of an UPDATE statement
NATURAL 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.

40. Returns rows if the condition is true for all the values in the list
X
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
All

41. A join across three tables can be expressed with the ________ join syntax.
ANSI
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.
NATURAL JOIN
**** 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

42. The RTRIM function is useful for eliminating ________ in a string.
KEEP INDEX
Extra spaces
Any
12:00:00 A.M

43. To revert back to a state that happened before you ran your change statement - you issue a ____________ command.
DICT_COLUMNS
DESC dict;
ROLLBACK
**** 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

44. When disabling a unique or primary key - you can keep the index if you specify the __________________ clause in the ALTER TABLE statement.
SYSDATE
Mathematical equations
RUN SCRIPT
KEEP INDEX

45. What is the tab in SQL Developer where data dictionary view information can be found?
BETWEEN
Self-joins
Null
Details

46. What is the main difference between the NOT EXISTS and the NOT IN operators?
IN ANY ALL SOME
BETWEEN
The way NULL values are treated
DICT_COLUMNS

47. Which one of the following string functions tells you how many characters are in a string?
LENGTH
Static or dynamic
DD-MON-YY
User-defined reports

48. What is the syntax used to indicate that you are using the Oracle Outer Join operator?
RIGHT LEFT JOIN
+
Null
4

49. To restart a sequence at a lower number - you can drop and ________ the sequence.
F12
Re-create
+
FALSE

50. 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
A correct statement
BETWEEN
ANY