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Solution to CS514 Final study questions
The analysis phase of database design includes which process? - ANS-Specifying requirements that are not dependent on a specific database system. When data is produced and stored as numeric, textual, or visual information, it varies in _____.
- ANS-format A database designer installs MySQL Community Edition to create a database. Which account does the designer use to gain full control of MySQL? - ANS-Root What does a user that interacts with a database use to read and write data? - ANS-Query language Which option is found on the Schemas tab in MySQL Workbench? - ANS-A list of available databases. The _____ SQL statement does not alter any database data. - ANS-SELECT What design consideration would apply to a database that has special performance requirements? - ANS-Structuring data properly on storage media. What links a host programming language to a database system? - ANS-API A database _____ is the implementation of database requirements in SQL with CREATE TABLE statements. - ANS-schema If a database system is processing three queries as part of a transaction and the third query fails, what happens to the transaction? - ANS-The successful query results are reversed, and the transaction is canceled. A database management system reads and writes data in a database, and _____. - ANS-ensures consistency and availability
When using the MySQL Command-Line Client, which character ends a command? - ANS-; In the following ER diagram, what does 'AlbumTitle' represent? - ANS-Attribute Which role focuses on creating software that interacts with a database? - ANS-Programmer In terms of database architecture, which component translates the query processor instructions into low-level file-system commands and is responsible for indexing the data? - ANS-Storage manager A user creates a table by using a SQL statement. The data type VARCHAR(11) is part of the statement. What does the value of (11) represent? - ANS-The number of characters allowed for the data type. When using a SQL statement to create a table, which data type is used to store a fractional value? - ANS-DECIMAL A database administrator uses which two SQL statements to view and then modify existing customer balances with a late fee? - ANS-SELECT, UPDATE When using the MySQL Workbench GUI, which icon will execute an SQL statement? - ANS- Lightning bolt Which database role focuses on database storage, response times, and optimization? - ANS- Designer Which type of database system is optimized for big data? - ANS-NoSQL Which principle defines data independence? - ANS-Physical design never affects query results. Which concept relates to software that reads and writes data in a database? - ANS- Management system How does a database system protect data when concurrent transactions occur? - ANS- Preventing multiple transactions with the same data at the same time. When a user interacts with a database, they can use a _____ to modify data with commands. - ANS-query language Refer to the Teacher and Class tables. To maintain referential integrity, which foreign key action rejects the deletion of the row containing Rosa Lopez? - ANS-RESTRICT In a relational database model, which concept refers to a finite sequence of values that are derived from defined domains? - ANS-Tuple
In MySQL, what is the result of TRUE AND NULL? - ANS-NULL What is the result of a relational operation? - ANS-Table A foreign key in which all columns are NULL is known as a _____ foreign key? - ANS-fully NULL Evaluate the given data and determine the correct result from the statement. - ANS- 485 In a relational database model, an attribute refers to which concept? - ANS-A uniquely named tuple position A NULL value represents _____ data. - ANS-missing A _____ is a collection of values with no inherent order. - ANS-set A _____ is a collection of values that are of the same type. - ANS-column What is converted into 0, 1, and M specifications during database design? - ANS-business rules When an entity-relationship model diagram is implemented within SQL, entities typically become _____, and relationships typically become _____. - ANS-tables, foreign keys A database team plans the creation of a new database. During which phase does the team capture data requirements? - ANS-Analysis A database designer interviews a sales team that will be using a new database. During the interview, the designer documents entities as _____, and relationships as _____. - ANS-nouns, verbs Paperback and hardcover books are mutually exclusive subsets of books. PaperBackBook and HardCoverBook _____ the supertype entity Book. - ANS-partition During database design, an entity with many optional attributes often becomes a(n) ______ entity. - ANS-Supertype A relationship minimum is the least number of instances of one entity that relates to a single instance of another entity. On an ER diagram, minima are usually specified as a _____ or _____.
- ANS-zero, one Entities that share common attributes and relationships become part of a new _____ entity. - ANS-supertype A database contains several relationships. Which is a valid relationship name? Correct! - ANS-Toys-Contains-Dolls
How are attributes documented in an entity-relationship diagram? - ANS-Within an entity rectangle. What is the greatest number of instances of one entity that can relate to a single instance of another entity? - ANS-Maximum What is the purpose of an entity synonym? - ANS-To reflect common name usage of the entity. When an entity-relationship model is implemented in SQL, an entity typically becomes a _____.
- ANS-table Which of the following is a set of things in entity-relationship modeling? - ANS-Entity Which popular ER model diagramming convention for cardinality depicts "many" in a relationship? - ANS-Three lines, called crow's feet, at the end of a relationship _______ entities have many common attributes and relationships. - ANS-Similar During database design, an ER _____ and _____ are usually developed in parallel. - ANS- diagram, glossary In some ER modeling conventions, _____ entities are called strong and _____ entities are called weak. - ANS-independent, dependent Which term describes the meaning of an attribute value? - ANS-Qualifier All spare parts belong to a product. A product must exist before spare parts become available and when a product is removed, spare parts are also removed. What type of entity is Product? - ANS-Master entity When considering an attribute maximum, which term represents when each attribute instance describes at most one entity instance? - ANS-Unique The entity Book includes Paperback, Hardcover, and Digital books. The attribute ChapterCount applies to both PaperBack and HardCover but not Digital. Digital has a TextToSpeech attribute. Which entity type is Digital? - ANS-Subtype When creating an ER diagram, a dependency relationship is drawn with an arrow pointing to a _____ entity. - ANS-master In the Entity-Has-Attribute relationship, what is a required attribute? - ANS-Each entity instance has at least one attribute instance.
UPDATE, SELECT, and ORDER BY are _____ in an SQL statement. - ANS-keywords What does SQL stand for? - ANS-Structured Query Language Choose the best data types to replace XXX and YYY. - ANS-VARCHAR(50), DECIMAL(8, 2) A _____ is a type of UNIQUE constraint applied to two or more columns. - ANS-table-level constraint Which language defines statements used for creating and dropping tables? - ANS-Data Definition Language Which SQL statement adds a new column Fax to the Supplier table? Correct! - ANS-ALTER TABLE SupplierADD Fax VARCHAR(30); A _____ constraint is used to define a column value that is not NULL when no value is provided.
- ANS-DEFAULT A database system has a database called onlineShop. What is the result of a CREATE statement that tries to create onlineShop a second time? - ANS-The statement produces an error that the database already exists. What should be added so NULL values are not allowed in ProductName? - ANS-VARCHAR(50) NOT NULL How many columns are created by the SQL statement below? - ANS- 6 Refer to the Supplier table. Which statement correctly changes Adan Stevens to Maria Stevens?
- ANS-UPDATE Supplier SET ContactName = 'Maria Stevens' WHERE SupplierId = 5; Branches that are similar in length in an index hierarchy are _____. - ANS-balanced A magnetic disk groups data into _____. - ANS-sectors With column-oriented storage, a block stores values for _____. - ANS-a single column Hash index entries are assigned to _____. - ANS-buckets What is a characteristic of a logical index? - ANS-Index does not change when a row moves to a new block.
Which table type interleaves rows of two or more tables in the same storage area? - ANS-Table clusters Which table type might use the modulo function to scramble row locations? - ANS-Hash A column contains grades from 0 to 10, but a WHERE clause specifies values from 0 to 100. A _____ index can be used to modify the column values and process the queries. - ANS-function In a logical index, pointers to table blocks are replaced with _____ values. - ANS-primary key What are two characteristics of an efficient bitmap index? - ANS-The database can quickly determine the block containing a table row from the index row number. Any indexed column contains relatively few distinct values. Which of the following is a characteristic of a B-tree index, but not a B+tree index? - ANS- Column values do not repeat at lower levels. The bottom level of a multi-level index is a _____index. - ANS-sorted single-level How are blocks read with a single-level index scan? - ANS-A scan reads all index blocks to find table blocks that contain selected rows. The table blocks are then read. A single-level index is a file that contains column values and pointers to _____ containing the column _____. - ANS-rows, value A relational database uses row-oriented storage to store an entire row within one _____. - ANS- block The sort column in a sorted table determines the _____ row order. - ANS-physical What are the performance characteristics of a heap table? - ANS-Insert, delete, and update operations are optimized, but not read operations. When working with multi-tables, a column that is available in all interleaved tables is known as a _____? - ANS-cluster key What is the fan-out for a multi-level index where index entries are 32 bytes and index blocks are 10 kilobytes? - ANS-Approximately 300 When performing a search, which scan type is fastest? - ANS-Index The time required to read or write the first byte of data is known as _____. - ANS-access time
In an online bank application that transfers funds from a checking account to a savings account, the _____ property ensures that the changes made to each account will not be lost due to a computer failure. - ANS-durability In which isolation level can dirty reads occur? - ANS-Read uncommitted Refer to the sequence below. What is the isolation level of transaction E? - ANS-Repeatable read Refer to the table and schedule below. The UPDATE statement in transaction T1 holds an exclusive lock on the Class table. With strict two-phase locking, when does the SELECT statement in transaction T2 execute? - ANS-After the ROLLBACK statement in T1 executes Refer to the schedule below. The initial value of B is 7 and C is 3. What is the value of A after the schedule executes? - ANS- 8 In an online bank application that transfers funds from a checking account to a savings account, the _____ property ensures that another transaction sees the transferred funds in one account or the other, but not in both, nor in neither. - ANS-isolation In a _____, all transactions come to a halt and remain at a standstill until one of the transactions is aborted. - ANS-deadlock In an online bank application that transfers funds from a checking account to a savings account, if a debit is made successfully from the checking account, the _____ property ensures that the corresponding credit is made to the savings account. - ANS-atomicity _____ allows all executed database instructions to be rolled back and to be restored in a prior transaction state. - ANS-SAVEPOINT A database administrator is updating one of the tables in the database. Which of the following techniques can prevent other database administrators from doing concurrent transactions to the same table? - ANS-Locking In the recovery log below, line 6 is a/an _____. - ANS-compensation record The username and password for the database in the configuration file of a web application is incorrect, so the web application cannot connect to the database. Which failure scenario best describes this example? - ANS-Transaction failure Refer to the initial Class table, SQL transaction, and final Class table, below. Which SAVEPOINT identifier is used to produce the final Class table? - ANS-S
A document that sequentially writes all the database operations is known as a/an _____. - ANS- recovery log A transaction _____ indicates the starting and ending statement of a database transaction. - ANS-boundary An operational database contains tables in third normal form. This design reduces _____. - ANS- redundancy When concurrently processing instructions, a shared memory computer works well with a common data set in a _____ memory space. - ANS-single Due to infrequent updates, many distributed databases use a _____ catalog. - ANS-replicated An organization deploys computer processing power and storage through a cloud provider's _____ services. - ANS-IaaS Which MySQL layer interacts directly with database users and administrators? - ANS-Tools A retailer is using a cloud-based transaction database and is experiencing sales fluctuations through the year. The ability for cloud resources to adapt to such change in utilization is called _____. - ANS-elasticity For integrity purposes, a distributed transaction requires all or _____ nodes to be updated in order to complete the transaction. - ANS-no In the query processor layer, the query optimizer generates a/an _____. - ANS-execution plan For reporting purposes, an organization establishes a(n) _____, which is separate from the operational database. - ANS-data warehouse During a data _____ phase, a database administrator refreshes a data warehouse and replaces incompatible keys with consistent values. - ANS-integration Operational data changes _____, while analytic data is updated _____. - ANS-in real time, at fixed intervals Which of the following is NOT a replica type? - ANS-Query A buffer manager retains _____ from the _____ to reduce data access time. - ANS-data blocks, file system Which MySQL component retains data blocks from storage in main memory for possible reuse?
In MySQL, spatial values _____ numeric values. - ANS-must be converted to numeric values using spatial functions prior to comparing with A complex type _____. - ANS-has a richer internal structure than a simple type How many types are possible for elements of a JSON document? - ANS- 6 The PosgreSQL ARRAY type is an example of a _____ type. - ANS-collection In Oracle Database, the object type _____. - ANS-can define either an individual column or an entire table In MySQL, a column has a SET type with 16 possible elements. How many bytes does each column value require? - ANS- 2 Which of the following does NOT appear in the Oracle Database's CREATE TYPE statement below? - ANS-Function body Elements can be nested in _____. - ANS-both XML and JSON Geographic data is _____. - ANS-defined with reference to the surface of the earth MySQL stores JSON values as _____. - ANS-an internal binary format MONEY is an example of a _____ type. - ANS-semantic What is wrong with the syntax of this XML? - ANS-The XML syntax is correct. A user-defined type is defined in terms of a _____ type. - ANS-base Elements of the _____ type can be repeated and are not ordered. - ANS-MULTISET How many bytes does POINT(18.5 - 20) require in internal MySQL format? - ANS- 24 One goal of object-relational database technology is to _____. - ANS-simplify database programming Which type is complex? - ANS-JSON What is the difference between the ENUM type and the SET type? - ANS-Each ENUM value has exactly one element, each SET value can have many elements. An R-tree has a ____ index with index entries containing ____. - ANS-multi-level, MBRs
In two dimensions, a minimum bounding rectangle is the _____? - ANS-the smallest rectangle aligned with the X- and Y-axes that contains a spatial value Which of the following database programming techniques is commonly used with object- oriented programming languages? - ANS-API Which of the following Connector/Python cursor properties returns the number of items affected by a query? - ANS-cursor.rowcount An application may use a _____ API, which in turn uses a _____ API to access unsupported data sources. - ANS-primary, secondary Database queries are commonly implemented using a declarative programming language because of which two main reasons? - ANS-Easier programming and faster execution A/An _____ will retrieve rows from a query that has multiple rows in the result set. - ANS- cursor API defines ____ for applications written in a procedural programming language and _____ for applications in object-oriented languages. - ANS-procedure calls, classes Which of the following is an example of database programming? - ANS-Creating a web application using Java and SQL In database APIs, ____ a query is a term used when compiling happens before executing the query. - ANS-preparing Which of the following database programming techniques is an extension of the SQL language that is typically used for database applications? - ANS-Procedural SQL Programming languages fall into either _____ or _____ paradigms. - ANS-imperative, declarative _____ allows a programmer to create an SQL query with a PREPARE statement at run-time. - ANS-Dynamic SQL In a Connector/Python program, the _____ method prevents _____, which is a type of attack that causes a program to execute malicious SQL statements. - ANS-cursor.execute(), SQL injection Which statements should replace XXX and YYY in the Connector/Python program? - ANS- row[1], row[0]
A NoSQL database that represents data using XML or JSON is called a _____ database. - ANS- document In a MongoDB shell, what happens when the following command executes? db.movies.insert({ name: "What About Bob?", year: 1991 }) - ANS-The document is added to the collection with a generated _id A _____ database stores related data as column families. - ANS-wide column A document database stores data as _____, while a relational database stores data as _____. - ANS-collections, tables Which approach splits data sets across multiple systems? - ANS-Sharding What is a characteristic of hash structure in a key-value database? - ANS-Buckets are stored on different machines, enabling horizontal scaling. Within each row of a wide column database, all columns of a family are stored ____ to optimize performance of read queries. - ANS-contiguously Which document type is commonly used by document databases? - ANS-XML A primary replica has failed in a document database. What happens as a result? - ANS-A secondary replica becomes active Which information would be acceptable in a key-value database? - ANS-Key = car make, value = Ford In a document database, a ________ assigns documents to shards. - ANS-It is NOT key-value A wide column database is similar to a relational database except that it does not support _____. - ANS-foreign keys and joins Which wide-column database has no single point of failure and is always available? - ANS- Cassandra Vertices in a graph database are similar to _____ in a relational table. Which language is created specifically for graph databases? - ANS-Gremlin Vertices in a graph database are similar to _____ in a relational table. - ANS-rows A database designer depicts a database as a graph with _____ representing entities. - ANS- vertices
Which graph database physical structure might combine a graph and a relational database? - ANS-Layered Strict consistency is enforced in some document databases by directing read queries to _____. - ANS-the primary replica In the MongoDB query, how is every student EXCEPT Larry selected? { name: { _____: _____ } } - ANS-$ne, "Larry" A NoSQL database that represents data as a key with multiple values is called a _____ database.
- ANS-wide column When a key-value database allows multiple values per key, how is each value identified? - ANS- By using a name for each value. A big data application generates 20,000 data entries per second. This rate is called what? - ANS- Velocity
