Question

Which of the following is NOT CORRECT about the roles of the DBMS components? (1 Point) Select one: The job of the query processor is to handle the modifications of both data and schema. The job of the storage manager is to modify the information to the data storage when requested. The job of the query processor and query optimizer is to issue commands to the storage manager. The job of the query processor is to obtain information requested from the data storage. All of the above. None of the above. O

Answer 1

Let us discuss the options one by one. At the end of the discussion we will know which option is not correct.

The job of the query processor is to handle the modifications of both data and schema.

Query can be of both the types – Data Definition Language (DDL) and Data Modification Language (DML). DDL can make changes to schema. Schema is the logical representation of the database. Creating a new table or altering an existing table can make changes to the schema. DML operations like insert, update, delete can make modification to data. So, this option is CORRECT.

The job of the storage manager is to modify information to the data storage when requested.

Storage manager handles the modifications to data storage depending upon the evaluation plan of the query processor. This option is CORRECT.

The job of the query processor and query optimizer is to issue commands to the storage manager.

The job of query processor is to process the query and producing output. The processing includes parsing the query, optimizing it, creating an evaluation plan and obtaining result from the storage using the storage manager. Role of query optimizer is to optimize the user written query to make it efficient. So, the optimizer does not issue commands to the storage manager. Thus, this option is NOT CORRECT. (Answer)

The job of the query processor is to obtain information requested from the data storage.

The query processor performs all the tasks from parsing the query to producing the result. This includes obtaining information for the data storage using the storage manager. So, this option is CORRECT.