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. Converting a text literal to DATE format requires the use of the...
+
TO_CHAR function
12:00:00 A.M
Combine

2. The ____________ icon allows you to execute multiple statements and emulates SQL *Plus as much as possible.
Inconsistencies
FALSE
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
RUN SCRIPT

3. What does the following function return? SELECT LENGTH(NULL) - FROM dual
Null
ANSI
Precision
Correlated

4. The ____________ clause on a CREATE TABLE statement can specify how much space to allocate.
Twice
Non-matching rows
When the table is small (unless your business rules require you too)
STORAGE

5. The key that most database designers prefer and is chosen by the system is the _____________ key.
X
Surrogate
Any
UNION

6. It is always good practice to include the old values in the WHERE clause of UPDATE to ensure that another session or user _________________ in the meantime.
Has not changed the name
Rounded edges
SUM
Another null

7. Which operator is most commonly used?
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.
UNION
Mathematical equations
Default is 14; when you use the default - you repeat the heading every 14 rows.

8. To restart a sequence at a lower number - you can drop and ________ the sequence.
Primary key/foreign key
Hide data
Re-create
ANY

9. You can use the ________________ to subtract months from a given date.
Running a script file
Inconsistencies
ADD
ADD_MONTHS function

10. Explain what is found in the All Objects report folder in SQL Developer
Equijoin
NATURAL JOIN
SELECT SYSDATE+1/96 - FROM dual
Lists all objects accessible for the chosen database connection. Also lists a helpful dependencies report for accessing change impact.

11. When you run a script in SQL*Plus you must give the...
Location of the file
Combine
Structured Query Language
999999.9999

12. List the reasons that a subquery could not be unnested.
DECODE
X
A correct statement
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

13. When is it not a good idea to use an index?
SELECT SYSDATE+1/96 - FROM dual
Mathematical equations
Multiple rows
When the table is small (unless your business rules require you too)

14. The COUNT function uses the __________ wildcard.
Asterisk
Multiple rows
Groups
Scalar

15. When you INSERT new information into a table - it is followed with a _______ keyword that contains the information that is going to be added to the table.
Scalar
VALUES
Command determines the total number of characters SQL *Plus displays in on line before beginning a new line.
Equijoin and correlated subquery

16. The NEXTVAL and CURRVAL pseudocolumns can be used in which of the following SQL constructs? Select all that apply.
VALUES clause of an INSERT statement
UNION operator
Twice
All

17. You can pass parameters from the operating system when ___________ in SQl*Plus
99.99
Running a script file
DICTIONARY
VALUES clause of an INSERT statement

18. When disabling a unique or primary key - you can keep the index if you specify the __________________ clause in the ALTER TABLE statement.
KEEP INDEX
F12
RENAME - COPY - DROP - TRUNCATE - LOCK - & COMMENT
ADD

19. Which one of the following string functions tells you how many characters are in a string?
Self-joins
SYSDATE
LENGTH
B-Tree Index

20. List the steps performed by a correlated subquery.
**** 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
UNION operator
RUN SCRIPT
Default is 14; when you use the default - you repeat the heading every 14 rows.

21. What is the data type you can use if you need an unlimited number of textual characters?
CLOB
Semicolon or forward slash
Multiple rows
X

22. In SQL Developer field names and table names are shown in the color _______.
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
SELECT SYSDATE+1/96 - FROM dual
Black
INNER JOIN

23. When using the following data: NUMBER(10 -4) - the lowest number you can possibly have is __________.
999999.9999
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
Non-matching rows
NATURAL JOIN

24. When you have issued a DELETE command - you can still ________ those rows and restore the information.
+
RENAME - COPY - DROP - TRUNCATE - LOCK - & COMMENT
X
Retrieve

25. What is the maximum value for a column defined as NUMBER(4 -2)?
V$
99.99
UNION
Structured Query Language

26. The ___________ operator tests whether a matching row cannot be found.
X
Run scripts
CLOB
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.

27. In a view you can give a column a different name than it has in the...
Correlated
Parent table
Running a script file
X

28. When using the following data: NUMBER(10 -4) - the # 10 is called the __________.
Precision
Time zone
ALL_OBJECTS
Nested

29. Information that is returned after you run your statement are found in the __________ tab in SQL Developer.
F12
Any
Non-matching rows
Results

30. Checks whether any value in the list makes the condition true.
LIKE
Any
Run scripts
Correlated

31. An outer join includes the result rows returned by an __________ plus extra rows where no matches are found.
Actual column
Time zone
Equijoin
ADD_MONTHS function

32. List the different types of data dictionary views.
USER_ - ALL_ - DBA_ - and V$
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
X
Testing functions

33. 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
Asterisk
Export Data
FALSE

34. List 4 aggregate functions
COUNT(registration_date) - AVG (capacity) - MIN (capacity) - MAX (capacity)
X
Equijoin and identical column names
Lists all objects accessible for the chosen database connection. Also lists a helpful dependencies report for accessing change impact.

35. Explain what a static data dictionary view is and how it is used
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.
ON
Columns
SUM

36. Write the syntax to rename index just_two_more_weeks_i to finally_i
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
FALSE
Multiple rows
RENAME just_two_more_weeks TO finally_i

37. Explain how the SPOOL command is used and what program it can be used in.
FALSE
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
+
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

38. The term ____________ ___________ is used to express a join that satisfies the join condition.
MODIFY
INNER JOIN
Time zone
Equijoin and correlated subquery

39. All SQL statements contained within a script must end with a _______________ - even if they are done in SQL Developer.
Script
Semicolon or forward slash
INNER JOIN
RENAME - COPY - DROP - TRUNCATE - LOCK - & COMMENT

40. The data type definitions NUMBER(10) and NUMBER(10 -0) are the...
ADD_MONTHS function
LIKE
Same
Hide data

41. Explain the differences in how an ANSI Full Outer Join and a Full Outer Join using the UNION Operator work
Actual column
Static or dynamic
X
Equijoin and identical column names

42. _________________ relationships are always optional relationships.
Recursive
UTC
ADD
Run scripts

43. Write a statement that drops the index need_to_pass_i
RIGHT LEFT JOIN
Crow's foot
DROP INDEX need_to_pass_i
Actual column

44. What is the name of the key automatically generated from a sequence?
Surrogate key
When the table is small (unless your business rules require you too)
DICT_COLUMNS
B-Tree Index

45. The focus of the logical data model is _____________
Export Data
DESC dict;
Business problems
ADD

46. Explain how you can optimize your queries with subqueries and the main advantage of doing so.
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.
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
Any
Self-joins

47. Returns rows if the condition is true for all the values in the list
VALUES clause of an INSERT statement
4
Orphan
All

48. Explain how Oracle treats locks when a database is being updated and needs to be viewed by other users.
All caps
SYSDATE
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 just_two_more_weeks TO finally_i

49. Write a statement for SQL*Plus that shows the dictionary.
Groups
ANSI
DESC dict;
Parent table

50. _________ rows are not allowed in the relational model.
Primary key/foreign key
Orphan
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
FALSE