Oracle 12c: SQL - Chapter 6
Based on the structure of the BOOKS table, which of the following is a valid SQL statement?
CREATE INDEX books_title_idx ON books (INITCAP(title));
Which of the following commands is used to create a function-based index?
CREATE INDEX...ON
The last value generated by a sequence is stored in the ____ pseudocolumn.
CURRVAL
A column has low cardinality if it contains many distinct values.
False
A large table containing a particular column that is frequently referenced by a WHERE clause would probably benefit from a(n) sequence .
False
A sequence serves as a nickname for a database object.
False
A(n) *index* can be used to generate a series of unique numbers.
False
All synonyms are PUBLIC.
False
An index is implicitly created when a NOT NULL constraint is added to a table.
False
An index is implicitly created whenever a(n) *CHECK* constraint is created for a table column.
False
The *GENERATE* option can be used to have a sequence pre-generate a set of numbers before they are requested by a user.
False
The NEXTVALUE pseudocolumn is used to actually generate the next value in a sequence.
False
The USER_ALL data dictionary view displays information about all the relevant objects owned by the user.
False
The USER_SEQ data dictionary view can be used to verify sequence settings.
False
The default value for the INCREMENT BY clause is two .
False
The ____ clause is used to specify the interval between two sequential values.
INCREMENT BY
Which of the following is a pseudocolumn?
NEXTVAL
An index is not implicitly created when which type of constraint is created?
NOT NULL
A sequence value may be set as a DEFAULT value for a column.
True
A(n) *index* can be used to quickly determine whether a value already exists in a specific column.
True
A(n) index can be created based on more than one column.
True
A(n) sequence can be used to generate a series of numeric values.
True
An explicitly created index can be dropped with the DROP INDEX command.
True
If the minimum value for a sequence is not specified, then NOMINVALUE will be assumed as the default.
True
The NEXTVAL pseudocolumn can be referenced in an INSERT command to add the value to a database table.
True
The START WITH clause of a sequence cannot be reset with the ALTER SEQUENCE command.
True
The USER_INDEXES data dictionary view can be used to verify existing indexes.
True
The default beginning value for a sequence is *one*.
True
The highest possible value for a descending sequence is -1.
True
To change the starting value for a sequence, the sequence must be dropped and then re-created.
True
When a positive value is assigned to the INCREMENT BY clause of the CREATE SEQUENCE command, numeric values are generated in ascending order.
True
Which of the following is a valid SQL statement when referencing a sequence?
none of the above
Which of the following can be created so other users will not need to prefix a table owned by user Jeff with his schema name?
synonym
Which of the following is not a valid statement concerning identity columns.
A DEFAULT clause may be assigned
Which of the following is a correct statement?
A PUBLIC synonym can be referenced by any user.
Which option is used to have Oracle12c pre-generate a set of values and store those values in the server's memory?
CACHE
Which command will create an index?
CREATE INDEX indexname ON tablename (columnname)
Which command will create a sequence named NEWSEQUENCE to generate a series of integers?
CREATE SEQUENCE newsequence;
Which command will create a synonym for a table?
CREATE SYNONYM synonymname FOR tablename;
Which of the following commands can be used to remove a sequence from a database?
DROP SEQUENCE
Which of the following is used to establish a minimum or maximum value, respectively, for a sequence?
MINVALUE | MAXVALUE
Which of the following statements about NEXTVAL and CURRVAL is incorrect?
NEXTVAL and CURRVAL are pseudocolumns that store unique names for database objects.
To remove a PUBLIC synonym, you must include the ____ keyword in the DROP command.
PUBLIC
Which of the following sequence settings cannot be changed with the ALTER SEQUENCE command?
START WITH
When working with cached sequence values, which of the following is correct?
When a value has been generated and cached, that value has been assigned and cannot be regenerated until the sequence begins a new cycle.
An index can be created ____.
both a and b
Which of the following contains the ROWID of referenced rows?
index
Which of the following commands can be used to modify an index?
none of the above
Which of the following is defined in Oracle12 as simply anything that has a name and a defined structure?
object
A(n) ____ synonym is used by an individual to reference objects owned by that person.
private