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. Oracle uses the outer join operator to indicate that nulls are shown for...
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
RUN SCRIPT
Surrogate key
Non-matching rows

2. Explain in detail the impact of INDEXES and how they are used by Oracle.
Scale
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.
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
UNION

3. Write a solution that adds 20 minutes to a given date.
Crow's foot
SELECT SYSDATE+1/96 - FROM dual
Script
VALUES

4. Instead of using the Oracle Outer Join Operator or the ANSI syntax - you can achieve the same result with two SQL statements: ____________ and a ____________
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
Equijoin and correlated subquery
CLOB
2000

5. An outer join includes the result rows returned by an __________ plus extra rows where no matches are found.
Structured Query Language
Equijoin
Columns
Testing functions

6. List the reasons that a subquery could not be unnested.
Nested
DECODE
X
ADD_MONTHS function

7. What is the syntax used to indicate that you are using the Oracle Outer Join operator?
Run scripts
Self-joins
4
+

8. FEEDBACK
99.99
X
Command returns the number of records returned by a query.
DICTIONARY

9. SQL Developer's ____________________ option allows you to selectively export certain rows and columns.
Hide data
Fractional seconds
Null
Export Data

10. 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.
Command returns the number of records returned by a query.
Details
Committed
FALSE

11. A _________ subquery returns a single column with a single row
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
RIGHT LEFT JOIN
LIKE
Scalar

12. Checks whether any value in the list makes the condition true.
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
User-defined reports
ADD

13. The _____________ clause determines how rows are grouped.
DROP INDEX need_to_pass_i
NATURAL JOIN
GROUP BY
Mathematical equations

14. 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
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.
Recursive
X

15. Write a statement that drops the index need_to_pass_i
Extra spaces
DROP INDEX need_to_pass_i
Parent table
ON

16. The key that most database designers prefer and is chosen by the system is the _____________ key.
Asterisk
Default is 14; when you use the default - you repeat the heading every 14 rows.
BETWEEN
Surrogate

17. The TIMESTAMP WITH LOCAL TIME ZONE data type allows...
DECODE
Non-matching rows
Fractional seconds
X

18. NUMBER functions can be...
Export Data
Nested
Parent table
VALUES

19. The TRUNC function on a date without a format model truncates the timestamp to...
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.
12:00:00 A.M
Hide data
4000

20. You can __________ DISTINCT and a GROUP BY clause in the same SELECT statement.
Static or dynamic
Semicolon or forward slash
Combine
DICTIONARY

21. LINESIZE
Command determines the total number of characters SQL *Plus displays in on line before beginning a new line.
MINUS
Equijoin and correlated subquery
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

22. You use the _________ keyword to add columns or constraints to a table.
99.99
ADD
Results
Extra spaces

23. 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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24. The RTRIM function is useful for eliminating ________ in a string.
Dynamic SQL is used to be continuously updated by the background processes in the Oracle instance but never by the user.
Surrogate
Extra spaces
ROLLBACK

25. How many characters can be stored in the CHAR column/field?
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
SET clause of an UPDATE statement
2000
SYSDATE

26. Match each of the SQL commands on the left with a verb from the list.
Implicit conversion
Control - Revoke - Define - TRUNCATE Manipulate - MERGE
Actual column
Retrieve

27. The same function can be used ______ in a SELECT statement.
RENAME just_two_more_weeks TO finally_i
Self-joins
Twice
VALUES clause of an INSERT statement

28. The purpose of the HAVING clause is to eliminate___________.
GROUP BY
Combine
Groups
Precision

29. In a view you can give a column a different name than it has in the...
Parent table
ANY
ROLLBACK
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

30. The _______ function lets you perform if-then-else functionality with the SQL language.
DECODE
Both MIN and MAX
VALUES
COMMIT

31. __________________ inserts the current date and time.
F12
SYSDATE
Asterisk
999999.9999

32. What is the tab in SQL Developer where data dictionary view information can be found?
Details
STORAGE
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.
4000

33. A join across three tables can be expressed with the ________ join syntax.
Lists all objects accessible for the chosen database connection. Also lists a helpful dependencies report for accessing change impact.
ANSI
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
99.99

34. When returning multiple rows - a subquery must contain the _____ - _____ - _____ - or ______ operator - otherwise Oracle will return an error
Both MIN and MAX
Groups
IN ANY ALL SOME
DICT_COLUMNS

35. Comparison operators can compare multiple _________________.
Columns
VALUES clause of an INSERT statement
SELECT DISTINCT menu FROM restaurant
Asterisk

36. List the steps performed by a correlated subquery.
Hide data
**** 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
Month ddth - yyyy
Running a script file

37. Explain what a static data dictionary view is and how it is used
Black
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.
The indexed column is part of an expression. In this case - consider creating a function-based index instead
B-Tree Index

38. How many characters can you have using the VARCHAR data type?
SELECT DISTINCT menu FROM restaurant
4000
User-defined reports
VALUES clause of an INSERT statement

39. To equijoin a table with another table involves matching the...
Surrogate
Common column value
Fractional seconds
Testing functions

40. 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)
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
KEEP INDEX
VALUES

41. A calculation with a null always yields...
Logical unit of work
X
Export Data
Another null

42. The ___________ operator tests whether a matching row cannot be found.
X
KEEP INDEX
DICT_COLUMNS
NATURAL JOIN

43. A transaction is a...
UNION operator
ALL_OBJECTS
Logical unit of work
User-defined reports

44. SQL*Plus is used more than SQL Developer when you need to...
12:00:00 A.M
KEEP INDEX
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
Run scripts

45. Users can only see changes made to a database once they have been...
FALSE
The way NULL values are treated
Committed
RUN SCRIPT

46. Joins involving multiple columns must always follow the ____________ relationship path.
Script
**** 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
Mathematical equations
Primary key/foreign key

47. List 6 Table-Related Menu Choices
RENAME - COPY - DROP - TRUNCATE - LOCK - & COMMENT
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.
Control - Revoke - Define - TRUNCATE Manipulate - MERGE
IN ANY ALL SOME

48. Subqueries can return...
Equijoin
When the table is small (unless your business rules require you too)
Multiple rows
**** 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

49. SQL Developer provides an extensive list of useful reports and offers the capability to create your own...
When the table is small (unless your business rules require you too)
Primary key/foreign key
User-defined reports
Command determines the total number of characters SQL *Plus displays in on line before beginning a new line.

50. The COUNT function is useful for determining whether a table has...
Data
COMMIT
NATURAL JOIN
Time zone