Oracle PL 1z0-071 Full Course Free

The query uses two functions: ROUND and TRUNC. The ROUND function will round the number 156.00 to the nearest hundred because of the -2 which specifies the number of decimal places to round to. This will result in 200. Then the TRUNC function truncates this number to the nearest 10, due to the -1 argument, which will give us 200 as the result since truncation does not change the rounded value in this case.

A. 16 (Incorrect)

B. 160 (Incorrect)

C. 150 (Incorrect)

D. 200 (Incorrect)

E. 100 (Incorrect)

In Oracle Database 12c, when creating an external table using the CREATE TABLE ... ORGANIZATION EXTERNAL statement, there are certain clauses that are mandatory for the command to execute successfully.

Statement C, the LOCATION clause, is required. The LOCATION clause specifies one or more external data source locations, typically a file or a directory that the external table will read from. Without this, Oracle would not know where to find the external data for the table.

Statement E, the access driver TYPE clause, is also required. The access driver tells Oracle how to interpret the format of the data files. The most common access driver is ORACLE_LOADER, which allows the reading of data files in a format compatible with the SQL*Loader utility. Another option could be ORACLE_DATAPUMP, which reads data in a Data Pump format.

Statements A, B, and D are not strictly required for the command to execute successfully, although they are often used in practice:

A, the DEFAULT DIRECTORY clause, is not mandatory if you have specified the full path in the LOCATION clause, but it is a best practice to use it to avoid hard-coding directory paths in the LOCATION clause.

B, the REJECT LIMIT clause, is optional and specifies the maximum number of errors to allow during the loading of data. If not specified, the default is 0, meaning the load will fail upon the first error encountered.

D, the ACCESS PARAMETERS clause, is where one would specify parameters for the access driver, such as field delimiters and record formatting details. While it is common to include this clause to define the format of the external data, it is not absolutely required for the command to execute; defaults would be used if this clause is omitted.

For reference, you can find more details in the Oracle Database SQL Language Reference for version 12c, under the CREATE TABLE statement for external tables.

Key components of an Entity-Relationship Model (ERM) include:

B. an attribute: Attributes are properties or characteristics of an entity, such as a person's name, date of birth, etc., and are essential in describing the data aspects of an entity in an ER model.

E. a relationship: Relationships describe how entities interact with each other within the database structure, such as a customer placing an order.

F. an entity: Entities are the key components of an ER model, representing objects or things within the domain that have a distinct existence, like 'Customer' or 'Order'.

Incorrect options:

A: A table is a database structure used to implement an entity in relational databases, not a component of the ER model itself.

C: While unique identifiers are crucial in database implementation (typically as primary keys), they are a specific attribute type, not a general component of ER models.

D: An activity is not a component of an ER model; activities relate more to process models or behavioral models in systems design.

In Oracle SQL, the correct way to check for non-null values is to use the IS NOT NULL condition. Using != NULL or <> NULL is incorrect because NULL represents the absence of any value, and you cannot use equality or inequality operators to check for NULL.

C. SELECT cust_first_name, cust_credit_limit * .05 AS DUE_AMOUNT FROM customers WHERE cust_income_level IS NOT NULL AND cust_credit_limit IS NOT NULL; This query will correctly filter out any customers with a NULL income level or credit limit and then calculate the due amount as 5% of their credit limit for the remaining customers.

References:

Oracle Database SQL Language Reference 12c, especially sections on conditions and expressions that deal with NULL values.