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. SELECT LIST of a subquery in an INSERT statement
Non-matching rows
SET clause of an UPDATE statement
UNION operator
Another null

2. A transaction is a...
INNER JOIN
SELECT SYSDATE+1/96 - FROM dual
Dynamic SQL is used to be continuously updated by the background processes in the Oracle instance but never by the user.
Logical unit of work

3. When you want to run a script in either SQL*Plus or SQL Developer - you can use a ______ or the _________ command.
Committed
Command returns the number of records returned by a query.
@ or START
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

4. Write a statement that drops the index need_to_pass_i
DROP INDEX need_to_pass_i
Null
Groups
STORAGE

5. Self-joins are useful for performing comparisons and checking for ___________ in data.
Business problems
Actual column
Inconsistencies
COUNT(registration_date) - AVG (capacity) - MIN (capacity) - MAX (capacity)

6. When using the data NUMBER(10 -4) there will be _______ digits following the decimal point.
Location of the file
Black
4
FALSE

7. In SQL Developer field names and table names are shown in the color _______.
DICT_COLUMNS
12:00:00 A.M
Common column value
Black

8. What is the name of the key automatically generated from a sequence?
Self-joins
Surrogate key
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

9. Write the syntax to rename index just_two_more_weeks_i to finally_i
Recursive
RENAME just_two_more_weeks TO finally_i
SUM
Export Data

10. Explain what is found in the All Objects report folder in SQL Developer
Lists all objects accessible for the chosen database connection. Also lists a helpful dependencies report for accessing change impact.
DD-MON-YY
RUN SCRIPT
COUNT(registration_date) - AVG (capacity) - MIN (capacity) - MAX (capacity)

11. What is the command you would type into SQL*Plus if you needed to know the definition for each column of a table?
VALUES
Lists all objects accessible for the chosen database connection. Also lists a helpful dependencies report for accessing change impact.
DICT_COLUMNS
The way NULL values are treated

12. The ___________ operator tests whether a matching row cannot be found.
X
KEEP INDEX
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

13. SQL Developer provides an extensive list of useful reports and offers the capability to create your own...
Leading-edge
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.
Self-joins
User-defined reports

14. List the reasons that a subquery could not be unnested.
Results
X
SUM
SELECT SYSDATE+1/96 - FROM dual

15. SELECT * FROM instructor ORDER BY phone
+
Command determines the total number of characters SQL *Plus displays in on line before beginning a new line.
A correct statement
2000

16. Which one of the following string functions tells you how many characters are in a string?
2000
Crow's foot
LENGTH
UNION operator

17. Queries that are found in parentheses are done first - just as in the order of operations when doing...
Dynamic SQL is used to be continuously updated by the background processes in the Oracle instance but never by the user.
Recursive
Semicolon or forward slash
Mathematical equations

18. UNION ALL does not sort - therefore it is less time consuming to use than the...
UNION operator
KEEP INDEX
SUM
Actual column

19. Explain the differences in how an ANSI Full Outer Join and a Full Outer Join using the UNION Operator work
Command determines the total number of characters SQL *Plus displays in on line before beginning a new line.
MODIFY
Retrieve
X

20. In a view you can give a column a different name than it has in the...
KEEP INDEX
Has not changed the name
Equijoin
Parent table

21. List 4 aggregate functions
ANY
V$
ADD
COUNT(registration_date) - AVG (capacity) - MIN (capacity) - MAX (capacity)

22. Write a solution that adds 20 minutes to a given date.
Combine
Black
SELECT SYSDATE+1/96 - FROM dual
B-Tree Index

23. Explain how Oracle treats locks when a database is being updated and needs to be viewed by other users.
Scale
Crow's foot
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
MODIFY

24. The __________ operator is inclusive of the two values specified.
Combine
LIKE
Optional
BETWEEN

25. When disabling a unique or primary key - you can keep the index if you specify the __________________ clause in the ALTER TABLE statement.
X
KEEP INDEX
12:00:00 A.M
DECODE

26. Checks whether any value in the list makes the condition true.
COUNT(registration_date) - AVG (capacity) - MIN (capacity) - MAX (capacity)
Any
Hide data
RENAME just_two_more_weeks TO finally_i

27. What is the first column of a composite index called?
@ or START
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.
RIGHT LEFT JOIN
Leading-edge

28. Explain how Substitution Variables are used when writing scripts.
Data
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.
RUN SCRIPT
TO_CHAR function

29. The NEXTVAL and CURRVAL pseudocolumns can be used in which of the following SQL constructs? Select all that apply.
X
Structured Query Language
Optional
VALUES clause of an INSERT statement

30. The key that most database designers prefer and is chosen by the system is the _____________ key.
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
Both MIN and MAX
DESC dict;
Surrogate

31. A calculation with a null always yields...
Command returns the number of records returned by a query.
All
Another null
Location of the file

32. If a graphical representation of a table's box has __________ it means that the relationship is identifying.
Asterisk
4000
Rounded edges
Location of the file

33. The ________ operator cannot compare against a list of values.
LIKE
B-Tree Index
RENAME just_two_more_weeks TO finally_i
RIGHT LEFT JOIN

34. _________ and __________ functions are opposites of each other and provide a value in a group of rows.
Leading-edge
All
COMMIT
Both MIN and MAX

35. Which format mask displays December 31st - 1999?
Month ddth - yyyy
Nested
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.
ADD

36. The ____________ icon allows you to execute multiple statements and emulates SQL *Plus as much as possible.
RIGHT LEFT JOIN
RUN SCRIPT
COMMIT
Data

37. When is it not a good idea to use an index?
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.
UNION operator
When the table is small (unless your business rules require you too)
Surrogate key

38. The ______ depicts the M of a 1:M relationship.

39. What is the syntax used to indicate that you are using the Oracle Outer Join operator?
+
Crow's foot
X
Semicolon or forward slash

40. What is the Oracle data dictionary called that contains a set of tables and views containing the data about the database?
Default is 14; when you use the default - you repeat the heading every 14 rows.
Self-joins
ALL_OBJECTS
SET clause of an UPDATE statement

41. LINESIZE
Semicolon or forward slash
Testing functions
Null
Command determines the total number of characters SQL *Plus displays in on line before beginning a new line.

42. The Nonequijoin can use the ________________ operator to construct joins that are not based on equality of values.
**** 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
Common column value
BETWEEN
DICTIONARY

43. The ____________ keywords and the USING clause of the ANSI join syntax are mutually exclusive.
CLOB
Has not changed the name
ON
NATURAL JOIN

44. An outer join includes the result rows returned by an __________ plus extra rows where no matches are found.
Command returns the number of records returned by a query.
Leading-edge
Equijoin
Groups

45. When you have issued a DELETE command - you can still ________ those rows and restore the information.
Retrieve
Equijoin and correlated subquery
INNER JOIN
TO_CHAR function

46. 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
Leading-edge
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 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

47. ___________ subqueries allow you to reference columns from the outer query and execute the inner query repeatedly
Correlated
4000
Location of the file
DECODE

48. The ______ operator compares a list of values for equivalency
SYSDATE
ANY
The way NULL values are treated
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

49. The data type definitions NUMBER(10) and NUMBER(10 -0) are the...
RUN SCRIPT
CLOB
Script
Same

50. The TIMESTAMP WITH LOCAL TIME ZONE data type allows...
+
Fractional seconds
SET clause of an UPDATE statement
USER_ - ALL_ - DBA_ - and V$