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 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.
Surrogate
FALSE
Actual column
Equijoin

2. Which format mask displays December 31st - 1999?
Logical unit of work
ROLLBACK
Script
Month ddth - yyyy

3. When using the following data: NUMBER(10 -4) - the # 4 is called the __________.
Retrieve
Precision
Scale
SYSDATE

4. What is the data type you can use if you need an unlimited number of textual characters?
Fractional seconds
ANY
CLOB
RUN SCRIPT

5. What are the main components of a ROWID?
KEEP INDEX
CLOB
ALL_OBJECTS
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.

6. Explain how the SPOOL command is used and what program it can be used in.
BETWEEN
DICT_COLUMNS
Optional
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

7. The key that most database designers prefer and is chosen by the system is the _____________ key.
RUN SCRIPT
Surrogate
LIKE
Self-joins

8. List the reasons that a subquery could not be unnested.
X
Lists all objects accessible for the chosen database connection. Also lists a helpful dependencies report for accessing change impact.
Recursive
Self-joins

9. The _______ operator determines common rows.
Common column value
@ or START
INTERSECT
**** 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

10. SELECT * FROM instructor ORDER BY phone
A correct statement
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.
Null
ROLLBACK

11. To restart a sequence at a lower number - you can drop and ________ the sequence.
SELECT SYSDATE+1/96 - FROM dual
Re-create
STORAGE
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.

12. Explain how Substitution Variables are used when writing scripts.
COMMIT
V$
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.
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.

13. A _________ subquery returns a single column with a single row
Equijoin and identical column names
DESC dict;
Scalar
RIGHT LEFT JOIN

14. NUMBER functions can be...
The way NULL values are treated
X
Nested
ADD

15. Write the syntax to rename index just_two_more_weeks_i to finally_i
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.
The way NULL values are treated
Has not changed the name
RENAME just_two_more_weeks TO finally_i

16. When returning multiple rows - a subquery must contain the _____ - _____ - _____ - or ______ operator - otherwise Oracle will return an error
Leading-edge
IN ANY ALL SOME
ADD
LENGTH

17. ___________ subqueries allow you to reference columns from the outer query and execute the inner query repeatedly
Correlated
DICT_COLUMNS
Orphan
VALUES clause of an INSERT statement

18. Converting a text literal to DATE format requires the use of the...
Equijoin
Crow's foot
A correct statement
TO_CHAR function

19. Match each of the SQL commands on the left with a verb from the list.
Implicit conversion
ANSI
Control - Revoke - Define - TRUNCATE Manipulate - MERGE
STORAGE

20. Oracle uses the outer join operator to indicate that nulls are shown for...
X
COUNT(registration_date) - AVG (capacity) - MIN (capacity) - MAX (capacity)
Non-matching rows
Scale

21. To equijoin a table with another table involves matching the...
Common column value
B-Tree Index
The way NULL values are treated
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.

22. _________ and __________ functions are opposites of each other and provide a value in a group of rows.
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
UNION
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
Both MIN and MAX

23. You can simplify the writing of SQL statements by writing SQL _________ that generate and execute other SQL statements.
ROLLBACK
All caps
The way NULL values are treated
Script

24. The ________ operator cannot compare against a list of values.
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.
Time zone
LIKE

25. What is the command you would type into SQL*Plus if you needed to know the definition for each column of a table?
Script
DICT_COLUMNS
The way NULL values are treated
Re-create

26. What does SQL stand for?
4
Default is 14; when you use the default - you repeat the heading every 14 rows.
Structured Query Language
UNION operator

27. What is the keyboard shortcut for the ROLLBACK command?
STORAGE
NATURAL JOIN
Mathematical equations
F12

28. You use the __________ keyword to change characteristics of a column.
DECODE
LENGTH
DD-MON-YY
MODIFY

29. What is the Oracle data dictionary called that contains a set of tables and views containing the data about the database?
ALL_OBJECTS
VALUES clause of an INSERT statement
Committed
BETWEEN

30. The purpose of the HAVING clause is to eliminate___________.
F12
The indexed column is part of an expression. In this case - consider creating a function-based index instead
MODIFY
Groups

31. To revert back to a state that happened before you ran your change statement - you issue a ____________ command.
Optional
Extra spaces
ROLLBACK
Hide data

32. The focus of the logical data model is _____________
NATURAL JOIN
Primary key/foreign key
F12
Business problems

33. When using the following data: NUMBER(10 -4) - the # 10 is called the __________.
COMMIT
Precision
IN ANY ALL SOME
Inconsistencies

34. To join four tables - you must have at least _____ join conditions.
V$
12:00:00 A.M
VALUES
Three

35. 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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36. An outer join includes the result rows returned by an __________ plus extra rows where no matches are found.
ADD_MONTHS function
USER_ - ALL_ - DBA_ - and V$
Asterisk
Equijoin

37. 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
Location of the file
UNION
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.

38. What is the name of the key automatically generated from a sequence?
COMMIT
IN ANY ALL SOME
Surrogate key
MINUS

39. Joins involving multiple columns must always follow the ____________ relationship path.
Command returns the number of records returned by a query.
Results
RENAME just_two_more_weeks TO finally_i
Primary key/foreign key

40. A join across three tables can be expressed with the ________ join syntax.
VALUES clause of an INSERT statement
Retrieve
ANSI
X

41. Explain in detail the impact of INDEXES and how they are used by Oracle.
RUN SCRIPT
UNION operator
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.
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

42. What is the maximum value for a column defined as NUMBER(4 -2)?
Three
Script
STORAGE
99.99

43. Explain what a static data dictionary view is and how it is used
The way NULL values are treated
Both MIN and MAX
Non-matching rows
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.

44. A calculation with a null always yields...
USER_ - ALL_ - DBA_ - and V$
X
User-defined reports
Another null

45. The data type definitions NUMBER(10) and NUMBER(10 -0) are the...
COUNT(registration_date) - AVG (capacity) - MIN (capacity) - MAX (capacity)
Same
Implicit conversion
Twice

46. When writing the syntax for finding information on three or more tables - the parenthesis around the ON clause is...
LENGTH
NATURAL JOIN
Implicit conversion
Optional

47. The ________________ is a type of statement whereby you retrieve data that exists in one table - but not in another.
999999.9999
Lists all objects accessible for the chosen database connection. Also lists a helpful dependencies report for accessing change impact.
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.
MINUS

48. PAGESIZE
Default is 14; when you use the default - you repeat the heading every 14 rows.
Any
X
USER_ - ALL_ - DBA_ - and V$

49. The ALTER SESSION statement can change the session's...
USER_ - ALL_ - DBA_ - and V$
Default is 14; when you use the default - you repeat the heading every 14 rows.
INNER JOIN
Time zone

50. Write a solution that adds 20 minutes to a given date.
SELECT SYSDATE+1/96 - FROM dual
ON
Month ddth - yyyy
All