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 ROWID pseudocolumn is not an ________- but it acts like one.
Actual column
Null
Running a script file
Recursive

2. In a view you can give a column a different name than it has in the...
Parent table
Structured Query Language
DECODE
Optional

3. Write a statement for SQL*Plus that shows the dictionary.
Retrieve
Script
DESC dict;
All

4. You can pass parameters from the operating system when ___________ in SQl*Plus
Running a script file
When the table is small (unless your business rules require you too)
SYSDATE
TO_CHAR function

5. The RTRIM function is useful for eliminating ________ in a string.
LENGTH
Primary key/foreign key
Testing functions
Extra spaces

6. What is the tab in SQL Developer where data dictionary view information can be found?
Groups
Self-joins
Script
Details

7. All SQL statements contained within a script must end with a _______________ - even if they are done in SQL Developer.
Control - Revoke - Define - TRUNCATE Manipulate - MERGE
Semicolon or forward slash
Scale
USER_ - ALL_ - DBA_ - and V$

8. 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.
**** 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
RIGHT LEFT JOIN
MODIFY
Primary key/foreign key

9. A calculation with a null always yields...
Equijoin
Another null
Nested
Re-create

10. Explain what a static data dictionary view is and how it is used
Mathematical equations
Equijoin and identical column names
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.
Results

11. The ____________ command makes changes permanent.
COMMIT
Combine
F12
DD-MON-YY

12. The ________________ is a type of statement whereby you retrieve data that exists in one table - but not in another.
Surrogate
Control - Revoke - Define - TRUNCATE Manipulate - MERGE
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

13. When you have issued a DELETE command - you can still ________ those rows and restore the information.
Nested
Retrieve
F12
Business problems

14. 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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15. The same function can be used ______ in a SELECT statement.
Twice
Details
Columns
SELECT SYSDATE+1/96 - FROM dual

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

17. List the different types of data dictionary views.
Surrogate key
USER_ - ALL_ - DBA_ - and V$
Null
COMMIT

18. What does SQL stand for?
Structured Query Language
FALSE
Has not changed the name
Leading-edge

19. The TRUNC function on a date without a format model truncates the timestamp to...
ANSI
12:00:00 A.M
SET clause of an UPDATE statement
Results

20. 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
ADD_MONTHS function
Columns
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.

21. What is the name of the key automatically generated from a sequence?
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.
Script
Surrogate key
Export Data

22. 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?
KEEP INDEX
DICTIONARY
RIGHT LEFT JOIN
Export Data

23. LINESIZE
Scalar
Command determines the total number of characters SQL *Plus displays in on line before beginning a new line.
Both MIN and MAX
X

24. What is the data type you can use if you need an unlimited number of textual characters?
2000
STORAGE
CLOB
FALSE

25. The using clause of the ANSI join syntax always assumes an...
UNION
RENAME just_two_more_weeks TO finally_i
Equijoin and identical column names
12:00:00 A.M

26. Explain how Oracle treats locks when a database is being updated and needs to be viewed by other users.
DECODE
Scale
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
Combine

27. The TIMESTAMP WITH LOCAL TIME ZONE data type allows...
F12
Fractional seconds
VALUES
Any

28. What is the most common DATE format found in SQL?
DD-MON-YY
RIGHT LEFT JOIN
Command determines the total number of characters SQL *Plus displays in on line before beginning a new line.
DICT_COLUMNS

29. To revert back to a state that happened before you ran your change statement - you issue a ____________ command.
VALUES clause of an INSERT statement
ROLLBACK
Export Data
RUN SCRIPT

30. If a graphical representation of a table's box has __________ it means that the relationship is identifying.
Rounded edges
Orphan
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.
Default is 14; when you use the default - you repeat the heading every 14 rows.

31. When is it not a good idea to use an index?
Results
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
When the table is small (unless your business rules require you too)
The indexed column is part of an expression. In this case - consider creating a function-based index instead

32. UNION ALL does not sort - therefore it is less time consuming to use than the...
LENGTH
4000
MINUS
UNION operator

33. _________________ relationships are always optional relationships.
RIGHT LEFT JOIN
Black
Recursive
Time zone

34. Explain in detail the impact of INDEXES and how they are used by Oracle.
**** 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
F12
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
Nested

35. The ______ operator compares a list of values for equivalency
ANY
FALSE
Results
Three

36. FEEDBACK
Command returns the number of records returned by a query.
999999.9999
DECODE
RUN SCRIPT

37. A transaction is a...
Logical unit of work
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
Structured Query Language
Details

38. When column names on the tables are different - you use the ______ condition.
GROUP BY
Re-create
Precision
ON

39. The __________ operator is inclusive of the two values specified.
MINUS
BETWEEN
LENGTH
Surrogate key

40. 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.
FALSE
Equijoin
4000
The indexed column is part of an expression. In this case - consider creating a function-based index instead

41. Comparison operators can compare multiple _________________.
Columns
DD-MON-YY
Equijoin and identical column names
Results

42. ____________ are useful for analyzing and exploring the relationships within your data
ADD
X
FALSE
Self-joins

43. To restart a sequence at a lower number - you can drop and ________ the sequence.
Re-create
Equijoin and identical column names
Precision
UTC

44. Oracle uses the outer join operator to indicate that nulls are shown for...
Time zone
@ or START
Non-matching rows
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

45. Explain why constraints are used when building tables.

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46. The ____________ clause on a CREATE TABLE statement can specify how much space to allocate.
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.
MINUS
ON
STORAGE

47. You use the __________ keyword to change characteristics of a column.
MODIFY
DESC dict;
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.
Details

48. NUMBER functions can be...
Nested
FALSE
MODIFY
4

49. __________________ inserts the current date and time.
Details
@ or START
SUM
SYSDATE

50. _________ and __________ functions are opposites of each other and provide a value in a group of rows.
Both MIN and MAX
**** 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
Three
Rounded edges