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. _________ and __________ functions are opposites of each other and provide a value in a group of rows.
Results
COMMIT
Both MIN and MAX
User-defined reports

2. The ____________ keywords and the USING clause of the ANSI join syntax are mutually exclusive.
NATURAL JOIN
Month ddth - yyyy
Self-joins
Black

3. Comparison operators can compare multiple _________________.
Data
Columns
Equijoin
DROP INDEX need_to_pass_i

4. Explain how Dynamic SQL is used and give an example of a Dynamic SQL statement.
Dynamic SQL is used to be continuously updated by the background processes in the Oracle instance but never by the user.
INTERSECT
The indexed column is part of an expression. In this case - consider creating a function-based index instead
Logical unit of work

5. The _______ function adds values together for a group of rows.
12:00:00 A.M
RIGHT LEFT JOIN
SUM
+

6. Explicit data type conversion is preferable to Oracle's...
Extra spaces
Testing functions
BETWEEN
Implicit conversion

7. When using the following data: NUMBER(10 -4) - the lowest number you can possibly have is __________.
999999.9999
A correct statement
Scale
Running a script file

8. Self-joins are useful for performing comparisons and checking for ___________ in data.
BETWEEN
All
Inconsistencies
Parent table

9. The same function can be used ______ in a SELECT statement.
Twice
Correlated
Columns
V$

10. 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.
A correct statement
V$
RIGHT LEFT JOIN
UNION operator

11. How many characters can you have using the VARCHAR data type?
Retrieve
UNION
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
4000

12. Write the syntax to rename index just_two_more_weeks_i to finally_i
+
Combine
STORAGE
RENAME just_two_more_weeks TO finally_i

13. The ____________ icon allows you to execute multiple statements and emulates SQL *Plus as much as possible.
Month ddth - yyyy
ANY
RUN SCRIPT
Multiple rows

14. _________________ relationships are always optional relationships.
Equijoin
Details
Non-matching rows
Recursive

15. List 6 Table-Related Menu Choices
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
RENAME - COPY - DROP - TRUNCATE - LOCK - & COMMENT
CLOB
Equijoin and identical column names

16. You use the __________ keyword to change characteristics of a column.
Crow's foot
MODIFY
Control - Revoke - Define - TRUNCATE Manipulate - MERGE
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.

17. The COUNT function is useful for determining whether a table has...
DESC dict;
LENGTH
Data
Run scripts

18. 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.
The way NULL values are treated
FALSE
INNER JOIN
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.

19. SELECT * FROM instructor ORDER BY phone
A correct statement
Fractional seconds
Same
When the table is small (unless your business rules require you too)

20. Which one of the following string functions tells you how many characters are in a string?
MODIFY
Command returns the number of records returned by a query.
LENGTH
RENAME just_two_more_weeks TO finally_i

21. Subqueries can return...
Control - Revoke - Define - TRUNCATE Manipulate - MERGE
Multiple rows
Dynamic SQL is used to be continuously updated by the background processes in the Oracle instance but never by the user.
Surrogate key

22. The time zone displacement value indicates the time difference from _______.
Has not changed the name
Self-joins
BETWEEN
UTC

23. Explain how Substitution Variables are used when writing scripts.
DESC dict;
ADD
Precision
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.

24. You use the _________ keyword to add columns or constraints to a table.
Actual column
The way NULL values are treated
ADD
A correct statement

25. Checks whether any value in the list makes the condition true.
Any
Scale
X
User-defined reports

26. The ROWID pseudocolumn is not an ________- but it acts like one.
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
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
VALUES clause of an INSERT statement
Actual column

27. 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
Hide data
Inconsistencies
Re-create

28. The ____________ command makes changes permanent.
F12
LIKE
Groups
COMMIT

29. _________ rows are not allowed in the relational model.
Default is 14; when you use the default - you repeat the heading every 14 rows.
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
Static or dynamic
Orphan

30. ____________ are useful for analyzing and exploring the relationships within your data
Self-joins
NATURAL JOIN
RIGHT LEFT JOIN
INTERSECT

31. You can use the ________________ to subtract months from a given date.
ADD_MONTHS function
Business problems
Re-create
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.

32. When you run a script in SQL*Plus you must give the...
Location of the file
MINUS
X
Primary key/foreign key

33. Explain the differences in how an ANSI Full Outer Join and a Full Outer Join using the UNION Operator work
DESC dict;
X
Inconsistencies
MINUS

34. Explain what is found in the All Objects report folder in SQL Developer
RUN SCRIPT
+
Lists all objects accessible for the chosen database connection. Also lists a helpful dependencies report for accessing change impact.
Hide data

35. The purpose of the HAVING clause is to eliminate___________.
Dynamic SQL is used to be continuously updated by the background processes in the Oracle instance but never by the user.
Groups
Testing functions
+

36. The TIMESTAMP WITH LOCAL TIME ZONE data type allows...
4
Twice
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.
Fractional seconds

37. The NEXTVAL and CURRVAL pseudocolumns can be used in which of the following SQL constructs? Select all that apply.
UNION
VALUES clause of an INSERT statement
Twice
The way NULL values are treated

38. The focus of the logical data model is _____________
Precision
Business problems
KEEP INDEX
SUM

39. Explain in detail the impact of INDEXES and how they are used by Oracle.
All caps
Static or dynamic
RIGHT LEFT JOIN
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

40. How many characters can be stored in the CHAR column/field?
Location of the file
2000
Run scripts
Committed

41. The ____________ clause on a CREATE TABLE statement can specify how much space to allocate.
STORAGE
FALSE
999999.9999
TO_CHAR function

42. Queries that are found in parentheses are done first - just as in the order of operations when doing...
All
Surrogate key
Details
Mathematical equations

43. FEEDBACK
Command returns the number of records returned by a query.
Scale
VALUES
Surrogate

44. What does the following function return? SELECT LENGTH(NULL) - FROM dual
SYSDATE
Testing functions
RENAME - COPY - DROP - TRUNCATE - LOCK - & COMMENT
Null

45. When writing the syntax for finding information on three or more tables - the parenthesis around the ON clause is...
Optional
MINUS
Retrieve
UNION

46. UNION ALL does not sort - therefore it is less time consuming to use than the...
Script
UNION operator
12:00:00 A.M
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.

47. When disabling a unique or primary key - you can keep the index if you specify the __________________ clause in the ALTER TABLE statement.
99.99
KEEP INDEX
DESC dict;
Any

48. List the steps performed by a correlated subquery.
INNER 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
VALUES clause of an INSERT statement
UNION

49. The ALTER SESSION statement can change the session's...
F12
Time zone
Month ddth - yyyy
When the table is small (unless your business rules require you too)

50. The RTRIM function is useful for eliminating ________ in a string.
DICTIONARY
Default is 14; when you use the default - you repeat the heading every 14 rows.
Run scripts
Extra spaces