Question 1

If a column has a YEAR TO MONTH INTERVAL data type,then the value +02-11 specifies a positive time interval of 2 years and 11 months.

Accepted Answer

A YEAR TO MONTH INTERVAL data type represents a period of time specified in years and months. Therefore, the value +02-11 specifies a positive time interval of 2 years and 11 months.

Question 2

If a user only specifies the time when setting a value for a DATE column,the date portion will default to the current time.

Accepted Answer

If a user only specifies the time when setting a value for a DATE column, it will result in an error, as a DATE column requires both a date and time value.

Question 3

Up to 6 GB of binary data can be stored in a BLOB column.

Accepted Answer

False

Question 4

When declaring a NUMBER data type,scale is the total number of digits both to the left and to the right of the decimal point.

Accepted Answer

When declaring a NUMBER data type, precision refers to the total number of digits including both to the left and to the right of the decimal point, while scale refers to the number of digits to the right of the decimal point.

Question 5

A TIMESTAMP data type is the same as a DATE data type,except that time zone can be specified.

Accepted Answer

A TIMESTAMP data type includes both date and time information, but does not inherently include time zone information, whereas a DATE data type includes only date information without time or time zone.

Question 6

A fixed-point number contains a specific number of decimal places.

Accepted Answer

A fixed-point number is a numerical representation that uses a specific number of digits or decimal places to represent a number. Therefore, a fixed-point number does contain a specific number of decimal places.

Question 7

The CHAR data types stores up to 4,000 characters.

Accepted Answer

The CHAR data type, in most relational database management systems, stores a fixed-length character string of up to a certain number of characters (typically ranging between 255 and 8,000). The exact limit varies between different DBMSs, but it is typically much lower than 4,000. Therefore, the statement is false.

Question 8

The Oracle DBMS stores columns of all data types in the same amount of space.

Accepted Answer

The Oracle DBMS uses varying amounts of space to store columns of different data types. For example, a column of type NUMBER(1) will use less space than a column of type NUMBER(38). Additionally, character-based data types like VARCHAR2 can use a varying amount of space based on the length of the data stored in the column.

Question 9

The following declaration represents a floating-point number: my_number NUMBER.

Accepted Answer

The keyword 'NUMBER' alone does not specify whether it is a floating-point or integer number. However, since it is stated in the question that it represents a floating-point number, we know that it is a floating-point type.

Question 10

The CHAR and VARCHAR2 data types store Unicode character data.

Accepted Answer

The CHAR and VARCHAR2 data types in Oracle store character data using the database character set, which may or may not be Unicode. Unicode data is specifically stored using the NCHAR and NVARCHAR2 data types.

Question 11

To create a table it is only necessary to specify column names.

Accepted Answer

In addition to column names, it is also necessary to specify the data type and any constraints for each column when creating a table.

Question 12

A user schema contains all database objects created by a user.

Accepted Answer

A user schema is a collection of all the database objects that are created by a user, such as tables, views, indexes, and stored procedures. Each user has its schema, which represents a namespace for the objects created by them.

Question 13

Using the CHAR data type causes a column value to be padded to the maximum declared size of the column.

Accepted Answer

The CHAR data type in SQL will pad the column value with spaces to the maximum declared size of the column. For example, if a column is declared as CHAR(10) and a value of "John" is inserted, it will be padded as "John      " with additional spaces to fill up to 10 characters.

Question 14

The SQL command to create a database table is an example of DML.

Accepted Answer

The SQL command to create a database table is actually an example of DDL (Data Definition Language) which is used to create and modify the structure of a database, not DML (Data Manipulation Language) which is used to manipulate data within a database.

Question 15

The VARCHAR2 data type can store up to 4,000 characters.

Accepted Answer

The VARCHAR2 data type can store up to 4,000 bytes, which is equivalent to approximately 4,000 characters depending on the character set being used.

Question 16

According to the Oracle Naming Standard,'-' (hyphen)is a legal character.

Accepted Answer

According to the Oracle Naming Standard, a '-' (hyphen) is not a legal character in identifiers such as table or column names; it interprets the hyphen as a minus sign, leading to syntax errors.

Question 17

A NOT NULL constraint is an example of a table constraint.

Accepted Answer

A NOT NULL constraint is a column constraint, not a table constraint, as it applies to individual columns to ensure they cannot contain NULL values.

Question 18

Given the column declaration name CHAR(5),if a user attempted to store the value "Jonathan" in the name column,only the first 5 characters would be stored.

Accepted Answer

The answer of Given the column declaration name CHAR(5),if a...

Question 19

The following declaration represents an integer: my_int number(4,2).

Accepted Answer

The syntax "my_int number(4,2)" does not correctly declare an integer in any widely used programming language; it appears to be a mix of syntaxes and is not a standard declaration for an integer variable.

Question 20

A primary key is defined using an integrity constraint.

Accepted Answer

A primary key is a type of integrity constraint that uniquely identifies each record in a database table. It is used to ensure data integrity, and is often created using a unique index. Therefore, a primary key is defined using an integrity constraint.

Quiz 2: Creating and Modifying Database Tables