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 TRUNC function on a date without a format model truncates the timestamp to...
12:00:00 A.M
Static or dynamic
User-defined reports
Leading-edge

2. The ___________ operator tests whether a matching row cannot be found.
Default is 14; when you use the default - you repeat the heading every 14 rows.
X
Combine
Results

3. The Nonequijoin can use the ________________ operator to construct joins that are not based on equality of values.
RENAME just_two_more_weeks TO finally_i
BETWEEN
Location of the file
Control - Revoke - Define - TRUNCATE Manipulate - MERGE

4. Explain how you can optimize your queries with subqueries and the main advantage of doing so.
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
Leading-edge
FALSE
MINUS

5. All SQL statements contained within a script must end with a _______________ - even if they are done in SQL Developer.
Semicolon or forward slash
Scale
Has not changed the name
Another null

6. FEEDBACK
Another null
Three
The way NULL values are treated
Command returns the number of records returned by a query.

7. You can __________ DISTINCT and a GROUP BY clause in the same SELECT statement.
4
Combine
Export Data
Optional

8. List the steps performed by a correlated subquery.
All
SELECT DISTINCT menu FROM restaurant
Another null
**** 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

9. Explain how Oracle treats locks when a database is being updated and needs to be viewed by other users.
Twice
Run scripts
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
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.

10. When you run a script in SQL*Plus you must give the...
FALSE
X
Location of the file
Testing functions

11. 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.
2000
FALSE
Time zone
IN ANY ALL SOME

12. Oracle uses the outer join operator to indicate that nulls are shown for...
Command determines the total number of characters SQL *Plus displays in on line before beginning a new line.
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
Non-matching rows

13. NUMBER functions can be...
Any
+
UTC
Nested

14. When you want to run a script in either SQL*Plus or SQL Developer - you can use a ______ or the _________ command.
Groups
RUN SCRIPT
SUM
@ or START

15. What is the data type you can use if you need an unlimited number of textual characters?
SELECT DISTINCT menu FROM restaurant
RENAME just_two_more_weeks TO finally_i
CLOB
Combine

16. What is the keyboard shortcut for the ROLLBACK command?
ANSI
User-defined reports
V$
F12

17. 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
Twice
Asterisk
Surrogate

18. The ______ operator compares a list of values for equivalency
GROUP BY
UNION
ANY
BETWEEN

19. Explain how Dynamic SQL is used and give an example of a Dynamic SQL statement.
Equijoin and correlated subquery
Dynamic SQL is used to be continuously updated by the background processes in the Oracle instance but never by the user.
Extra spaces
RENAME - COPY - DROP - TRUNCATE - LOCK - & COMMENT

20. ____________ are useful for analyzing and exploring the relationships within your data
Self-joins
Any
DECODE
4000

21. Information that is returned after you run your statement are found in the __________ tab in SQL Developer.
Implicit conversion
Running a script file
Results
Actual column

22. _________ and __________ functions are opposites of each other and provide a value in a group of rows.
Both MIN and MAX
Surrogate
The indexed column is part of an expression. In this case - consider creating a function-based index instead
Semicolon or forward slash

23. You use the _________ keyword to add columns or constraints to a table.
Scale
Fractional seconds
ADD
COMMIT

24. Joins involving multiple columns must always follow the ____________ relationship path.
RIGHT LEFT JOIN
FALSE
Primary key/foreign key
CLOB

25. What do views do that makes them so useful for security?
Hide data
UNION operator
USER_ - ALL_ - DBA_ - and V$
Self-joins

26. A transaction is a...
IN ANY ALL SOME
Logical unit of work
Non-matching rows
Parent table

27. When returning multiple rows - a subquery must contain the _____ - _____ - _____ - or ______ operator - otherwise Oracle will return an error
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.
Testing functions
IN ANY ALL SOME
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. Queries that are found in parentheses are done first - just as in the order of operations when doing...
Mathematical equations
RIGHT LEFT JOIN
Recursive
Has not changed the name

29. The term ____________ ___________ is used to express a join that satisfies the join condition.
Inconsistencies
INNER JOIN
Three
+

30. What is the maximum value for a column defined as NUMBER(4 -2)?
RENAME - COPY - DROP - TRUNCATE - LOCK - & COMMENT
Semicolon or forward slash
LENGTH
99.99

31. To equijoin a table with another table involves matching the...
**** 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
Columns
Three
Common column value

32. To place a line comment in your SQL statements - you first place a // at the beginning of the line.
STORAGE
FALSE
Testing functions
X

33. What does SQL stand for?
Structured Query Language
X
UNION operator
LENGTH

34. Explain the differences in how an ANSI Full Outer Join and a Full Outer Join using the UNION Operator work
When the table is small (unless your business rules require you too)
X
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.
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.

35. When using the data NUMBER(10 -4) there will be _______ digits following the decimal point.
Orphan
INNER JOIN
V$
4

36. The using clause of the ANSI join syntax always assumes an...
Equijoin and identical column names
Committed
INNER JOIN
Running a script file

37. Which format mask displays December 31st - 1999?
Mathematical equations
Scale
Month ddth - yyyy
Dynamic SQL is used to be continuously updated by the background processes in the Oracle instance but never by the user.

38. Write the syntax to rename index just_two_more_weeks_i to finally_i
CLOB
RENAME just_two_more_weeks TO finally_i
The way NULL values are treated
Actual column

39. The TIMESTAMP WITH LOCAL TIME ZONE data type allows...
STORAGE
Black
Rounded edges
Fractional seconds

40. Write a statement for SQL*Plus that shows the dictionary.
VALUES clause of an INSERT statement
DESC dict;
Rounded edges
When the table is small (unless your business rules require you too)

41. A join across three tables can be expressed with the ________ join syntax.
ANSI
Same
Crow's foot
DECODE

42. Explicit data type conversion is preferable to Oracle's...
SUM
X
Another null
Implicit conversion

43. What does the following function return? SELECT LENGTH(NULL) - FROM dual
X
VALUES clause of an INSERT statement
Null
DROP INDEX need_to_pass_i

44. How many characters can you have using the VARCHAR data type?
User-defined reports
4000
FALSE
Hide data

45. To revert back to a state that happened before you ran your change statement - you issue a ____________ command.
MINUS
ROLLBACK
Command determines the total number of characters SQL *Plus displays in on line before beginning a new line.
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.

46. Explain how Substitution Variables are used when writing scripts.
4
BETWEEN
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.
Structured Query Language

47. You can use the ________________ to subtract months from a given date.
UNION operator
ADD_MONTHS function
Retrieve
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.

48. Explain how the SPOOL command is used and what program it can be used in.
Run scripts
Non-matching rows
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
Static or dynamic

49. To join four tables - you must have at least _____ join conditions.
Three
DESC dict;
Orphan
ANSI

50. The _____________ clause determines how rows are grouped.
Scale
Time zone
GROUP BY
Rounded edges