WGU - C175 Exam With 100% Correct Answers 2023

3 Vs - Correct Answer-Three basic characteristics of Big Data databases: volume, velocity, and variety. abstract data type (ADT) - Correct Answer-Data type that describes a set of similar objects with shared and encapsulated data representation and methods. A(n) is generally used to describe complex objects. See also class. ad hoc query - Correct Answer-A "spur-of-the-moment" question. alias - Correct Answer-An alternative name for a column or table in a SQL statement. ALTER TABLE - Correct Answer-The SQL command used to make changes to table structure. When the command is followed by a keyword (ADD or MODIFY), it adds a column or changes column characteristics. American National Standards Institute (ANSI) - Correct Answer-The group that accepted the DBTG recommendations and augmented database standards in 1975 through its SPARC committee. analytical database - Correct Answer-A database focused primarily on storing historical data and business metrics used for tactical or strategic decision making. AND - Correct Answer-The SQL logical operator used to link multiple conditional expressions in a WHERE or HAVING clause. It requires that all conditional expressions evaluate to true. application programming interface (API) - Correct Answer-Software through which programmers interact with middleware. A(n) allows the use of generic SQL code, thereby allowing client processes to be database server-independent. atomic attribute - Correct Answer-An attribute that cannot be further subdivided to produce meaningful components. For example, a person's last name attribute cannot be meaningfully subdivided. atomicity - Correct Answer-The transaction property that requires all parts of a transaction to be treated as a single, indivisible, logical unit of work. All parts of a transaction must be completed or the entire transaction is aborted. attribute - Correct Answer-A characteristic of an entity or object. A(n) has a name and a data type. availability - Correct Answer-In the context of data security, it refers to the accessibility of data whenever required by authorized users and for authorized purposes. AVG - Correct Answer-A SQL aggregate function that outputs the mean average for a specified column or expression. balancing - Correct Answer-Ensuring that the processing load is distributed evenly among multiple servers. BETWEEN - Correct Answer-In SQL, a special comparison operator used to check whether a value is within a range of specified values. Big Data - Correct Answer-A movement to find new and better ways to manage large amounts of web-generated data and derive business insight from it, while simultaneously providing high performance and scalability at a reasonable cost. binary relationship - Correct Answer-An ER term for an association (relationship) between two entities. For example, PROFESSOR teaches CLASS. Boolean algebra - Correct Answer-A branch of mathematics that uses the logical operators OR, AND, and NOT. Boyce-Codd normal form (BCNF) - Correct Answer-A special type of third normal form (3NF) in which every determinant is a candidate key. A table in must be in 3NF. See also determinant. Business intelligence (BI) - Correct Answer-A comprehensive, cohesive, and integrated set of tools and processes used to capture, collect, integrate, store, and analyze data with the purpose of generating and presenting information to support business decision making. business rule - Correct Answer-A description of a policy, procedure, or principle within an organization. For example, a pilot cannot be on duty for more than 10 hours during a 24-hour period, or a professor may teach up to four classes during a semester. candidate key - Correct Answer-A minimal superkey; that is, a key that does not contain a subset of attributes that is itself a superkey. See key. cardinality - Correct Answer-A property that assigns a specific value to connectivity and expresses the range of allowed entity occurrences associated with a single occurrence of the related entity. cascading order sequence - Correct Answer-A nested ordering sequence for a set of rows, such as a list in which all last names are alphabetically ordered and, within the last names, all first names are ordered. class - Correct Answer-A collection of similar objects with shared structure (attributes) and behavior (methods). A(n) encapsulates an object's data representation and a method's implementation. are organized in a class hierarchy. class diagram notation - Correct Answer-The set of symbols used in the creation of class diagrams in UML object modeling. class diagrams - Correct Answer-A diagram used to represent data and their relationships in UML object notation. class hierarchy - Correct Answer-The organization of classes in a hierarchical tree in which each parent class is a superclass and each child class is a subclass. See also inheritance. client - Correct Answer-Any process that requests specific services from server processes in a client/server environment. client node - Correct Answer-One of three types of nodes used in the Hadoop Distributed File System (HDFS). A(n) acts as the interface between the user application and the HDFS. See also name node and data node. cloud database - Correct Answer-A database that is created and maintained using cloud services, such as Microsoft Azure or Amazon AWS. COMMIT - Correct Answer-The SQL command that permanently writes data changes to a database. complex object - Correct Answer-An object formed by several different objects in complex relationships. See also abstract data types. composite attribute - Correct Answer-An attribute that can be further subdivided to yield additional attributes. For example, a phone number such as may be divided into an area code (615), an exchange number (898), and a four-digit code (2368). Compare to simple attribute. composite entity - Correct Answer-An entity designed to transform an M:N relationship into two 1:M relationships. A(n) 's primary key comprises at least the primary keys of the entities that it connects. Also known as a bridge entity or associative entity. See also linking table. composite identifier - Correct Answer-In ER modeling, a key composed of more than one attribute. composite key - Correct Answer-A multiple-attribute key. conceptual model - Correct Answer-The output of the conceptual design process. A(n) provides a global view of an entire database and describes the main data objects, avoiding details. conceptual schema - Correct Answer-A representation of the conceptual model, usually expressed graphically. See also conceptual model. connectivity - Correct Answer-The type of relationship between entities. Classifications include 1:1, 1:M, and M:N. constraint - Correct Answer-A restriction placed on data, usually expressed in the form of rules. For example, "A student's GPA must be between 0.00 and 4.00." are important because they help to ensure data integrity. COUNT - Correct Answer-A SQL aggregate function that outputs the number of rows containing not null values for a given column or expression, sometimes used in conjunction with the DISTINCT clause. CREATE INDEX - Correct Answer-A SQL command that creates indexes on the basis of a selected attribute or attributes. CREATE TABLE - Correct Answer-A SQL command that creates a table's structures using the characteristics and attributes given. Crow's Foot notation - Correct Answer-A representation of the entity relationship diagram that uses a three-pronged symbol to represent the "many" sides of the relationship. cube cache - Correct Answer-In multidimensional OLAP, the shared, reserved memory area where data cubes are held. Using a(n) assists in speeding up data access. dashboards - Correct Answer-In business intelligence, a web-based system that presents key business performance indicators or information in a single, integrated view with clear and concise graphics. data - Correct Answer-Raw facts, or facts that have not yet been processed to reveal their meaning to the end user. data anomaly - Correct Answer-An abnormality in which inconsistent changes have been made to a database. For example, an employee moves, but the address change is not corrected in all files in the database. data cube - Correct Answer-The multidimensional data structure used to store and manipulate data in a multidimensional DBMS. The location of each data value in a(n) is based on its x-, y-, and z-axes. are static, meaning they must be created before they are used, so they cannot be created by an ad hoc query. data definition language (DDL) - Correct Answer-The language that allows a database administrator to define the database structure, schema, and subschema. data dependence - Correct Answer-A data condition in which data representation and manipulation are dependent on the physical data storage characteristics. data dictionary - Correct Answer-A DBMS component that stores metadata—data about data. Thus, a(n) contains the data definition as well as their characteristics and relationships. A(n) may also include data that are external to the DBMS. Also known as an information resource dictionary. data inconsistency - Correct Answer-A condition in which different versions of the same data yield different (inconsistent) results. data independence - Correct Answer-A condition in which data access is unaffected by changes in the physical data storage characteristics. data integrity - Correct Answer-In a relational database, a condition in which the data in the database complies with all entity and referential integrity constraints. data management - Correct Answer-A process that focuses on data collection, storage, and retrieval. Common functions include addition, deletion, modification, and listing. data manipulation language (DML) - Correct Answer-The set of commands that allows an end user to manipulate the data in the database, such as SELECT, INSERT, UPDATE, DELETE, COMMIT, and ROLLBACK. data mart - Correct Answer-A small, single-subject data warehouse subset that provides decision support to a small group of people. data model - Correct Answer-A representation, usually graphic, of a complex "real- world" data structure. are used in the database design phase of the Database Life Cycle. data modeling - Correct Answer-The process of creating a specific data model for a determined problem domain. data node - Correct Answer-One of three types of nodes used in the Hadoop Distributed File System (HDFS). The stores fixed-size data blocks (that could be replicated to other data nodes). See also client node and name node. data processing (DP) specialist - Correct Answer-The person responsible for developing and managing a computerized file processing system. data redundancy - Correct Answer-Exists when the same data is stored unnecessarily at different places. data visualization - Correct Answer-Abstracting data to provide information in a visual format that enhances the user's ability to effectively comprehend the meaning of the data. data warehouse - Correct Answer-An integrated, subject-oriented, time-variant, nonvolatile collection of data in a specialized database that stores historical and aggregated data in a format that provides support for decision making. database - Correct Answer-A shared, integrated computer structure that houses a collection of related data. A contains two types of data: end-user data (raw facts) and metadata. database design - Correct Answer-The process that yields the description of the database structure and determines the database components. The second phase of the Database Life Cycle. database management system (DBMS) - Correct Answer-The collection of programs that manages the database structure and controls access to the data stored in the database. database system - Correct Answer-An organization of components that defines and regulates the collection, storage, management, and use of data in a database environment. decision support system (DSS) - Correct Answer-An arrangement of computerized tools used to assist managerial decision making within a business. DELETE - Correct Answer-A SQL command that allows data rows to be deleted from a table. denormalization - Correct Answer-A process by which a table is changed from a higher- level normal form to a lower-level normal form, usually to increase processing speed. potentially yields data anomalies. dependency diagram - Correct Answer-A representation of all data dependencies (primary key, partial, or transitive) within a table. dependent - Correct Answer-An attribute whose value is determined by another attribute. derived attribute - Correct Answer-An attribute that does not physically exist within the entity and is discovered via an algorithm. For example, the Age might be by subtracting the birth date from the current date. desktop database - Correct Answer-A single-user database that runs on a personal computer. determinant - Correct Answer-Any attribute in a specific row whose value directly determines other values in that row. See also Boyce-Codd normal form (BCNF). determination - Correct Answer-The role of a key. In the context of a database table, the statement "A B" indicates that knowing the value of attribute A means that the value of attribute B can be looked up. digital data - Correct Answer-A data that represents other forms of data using specific machine language systems that can be interpreted by various technologies. dimension tables - Correct Answer-In a data warehouse, tables used to search, filter, or classify facts within a star schema. discipline-specific databases - Correct Answer-A database that contains data focused on specific subject areas. DISTINCT - Correct Answer-A SQL clause that produces only a list of values that are different from one another. domain - Correct Answer-In data modeling, the construct used to organize and describe an attribute's set of possible values. drill down - Correct Answer-To decompose data into more atomic components—that is, data at lower levels of aggregation. This approach is used primarily in a decision support system to focus on specific geographic areas, business types, and so on. DROP INDEX - Correct Answer-A SQL command that permanently deletes an index. DROP TABLE - Correct Answer-A SQL command that permanently deletes a table and its data. enterprise database - Correct Answer-The overall company data representation, which provides support for present and expected future needs. entity - Correct Answer-A person, place, thing, concept, or event for which data can be stored. See also attribute. entity instance - Correct Answer-A row in a relational table. Also known as occurrence. entity integrity - Correct Answer-The property of a relational table that guarantees each entity has a unique value in a primary key and that the key has no null values. entity occurrence - Correct Answer-A row in a relational table. Also known as instance. entity relationship diagram (ERD) - Correct Answer-A diagram that depicts an entity relationship model's entities, attributes, and relations. entity relationship model (ERM) - Correct Answer-A data model that describes relationships (1:1, 1:M, and M:N) among entities at the conceptual level with the help of ER diagrams. The was developed by Peter Chen. entity set - Correct Answer-A collection of like entities. eventual consistency - Correct Answer-A model for database consistency in which updates to the database will propagate through the system so that all data copies will be consistent eventually. existence-dependent - Correct Answer-A property of an entity whose existence depends on one or more other entities. In such an environment, the existence-independent table must be created and loaded first because the key cannot reference a table that does not yet exist. existence-independent - Correct Answer-A property of an entity that can exist apart from one or more related entities. Such a table must be created first when referencing an existence-dependent table. EXISTS - Correct Answer-In SQL, a comparison operator that checks whether a subquery returns any rows. extended relational data model (ERDM) - Correct Answer-A model that includes the object-oriented model's best features in an inherently simpler relational database structural environment. See extended entity relationship model (EERM). Extensible Markup Language (XML) - Correct Answer-A meta-language used to represent and manipulate data elements. Unlike other markup languages, permits the manipulation of a document's data elements. facilitates the exchange of structured documents such as orders and invoices over the Internet. external model - Correct Answer-The application programmer's view of the data environment. Given its business focus, an works with a data subset of the global database schema. external schema - Correct Answer-The specific representation of an external view; the end user's view of the data environment. extraction, transformation, and loading (ETL) - Correct Answer-In a data warehousing environment, the integrated processes of getting data from original sources into the data warehouse. includes retrieving data from original data sources ( ), manipulating the data into an appropriate form ( ), and storing the data in the data warehouse ( ). field - Correct Answer-An alphabetic or numeric character or group of characters that defines a characteristic of a person, place, or thing. For example, a person's Social Security number, address, phone number, and bank balance all constitute fields. file - Correct Answer-A named collection of related records. first normal form (1NF) - Correct Answer-The first stage in the normalization process. It describes a relation depicted in tabular format, with no repeating groups and a primary key identified. All nonkey attributes in the relation are dependent on the primary key. flags - Correct Answer-Special codes implemented by designers to trigger a required response, alert end users to specified conditions, or encode values. may be used to prevent nulls by bringing attention to the absence of a value in a table. foreign key (FK) - Correct Answer-An attribute or attributes in one table whose values must match the primary key in another table or whose values must be null. See key. fourth normal form (4NF) - Correct Answer-A table is in if it is in 3NF and contains no multiple independent sets of multivalued dependencies. FROM - Correct Answer-A SQL clause that specifies the table or tables from which data is to be retrieved. full functional dependence - Correct Answer-A condition in which an attribute is functionally dependent on a composite key but not on any subset of the key. functional dependence - Correct Answer-Within a relation R, an attribute B is on an attribute A if and only if a given value of attribute A determines exactly one value of attribute B. The relationship "B is dependent on A" is equivalent to "A determines B," and is written as A->B. general-purpose databases - Correct Answer-A database that contains a wide variety of data used in multiple disciplines. governance - Correct Answer-In business intelligence, the methods for controlling and monitoring business health and promoting consistent decision making. granularity - Correct Answer-The level of detail represented by the values stored in a table's row. Data stored at its lowest level of is said to be atomic data. GROUP BY - Correct Answer-A SQL clause used to create frequency distributions when combined with any of the aggregate functions in a SELECT statement. Hadoop - Correct Answer-A Java based, open source, high speed, fault-tolerant distributed storage and computational framework. uses low-cost hardware to create clusters of thousands of computer nodes to store and process data. Hadoop Distributed File System (HDFS) - Correct Answer-A highly distributed, fault- tolerant file storage system designed to manage large amounts of data at high speeds. hardware independence - Correct Answer-A condition in which a model does not depend on the hardware used in the model's implementation. Therefore, changes in the will have no effect on the database design at the conceptual level. HAVING - Correct Answer-A clause applied to the output of a GROUP BY operation to restrict selected rows. hierarchical model - Correct Answer-An early database model whose basic concepts and characteristics formed the basis for subsequent database development. This model is based on an upside-down tree structure in which each record is called a segment. The top record is the root segment. Each segment has a 1:M relationship to the segment directly below it. hub - Correct Answer-A warehouse of data packets housed in a central location on a local area network. It contains multiple ports that copy the data in the data packets to make it accessible to selected or all segments of the network. identifiers - Correct Answer-One or more attributes that uniquely each entity instance. IN - Correct Answer-In SQL, a comparison operator used to check whether a value is among a list of specified values. index - Correct Answer-An ordered array of key values and row ID values (pointers). key. information - Correct Answer-The result of processing raw data to reveal its meaning. consists of transformed data and facilitates decision making. inheritance - Correct Answer-In the object-oriented data model, the ability of an object to the data structure and methods of the classes above it in the class hierarchy. See also class hierarchy. inner query - Correct Answer-A query that is embedded or nested inside another query. Also known as a nested query or a subquery. INSERT - Correct Answer-A SQL command that allows the insertion of one or more data rows into a table. internal model - Correct Answer-In database modeling, a level of data abstraction that adapts the conceptual model to a specific DBMS model for implementation. The is the representation of a database as "seen" by the DBMS. In other words, the requires a designer to match the conceptual model's characteristics and constraints to those of the selected implementation model. internal schema - Correct Answer-A representation of an internal model using the database constructs supported by the chosen database. International Organization for Standardization (ISO) - Correct Answer-An organization formed to develop standards for diverse network systems. IS NULL - Correct Answer-In SQL, a comparison operator used to check whether an attribute has a value. islands of information - Correct Answer-In the old file system environment, pools of independent, often duplicated, and inconsistent data created and managed by different departments. iterative process - Correct Answer-A process based on repetition of steps and procedures. key - Correct Answer-One or more attributes that determine other attributes. See also superkey, candidate key, primary key (PK), secondary key, and foreign key. key attribute - Correct Answer-The attributes that form a primary key. See also prime attribute. key performance indicators (KPIs) - Correct Answer-In business intelligence, quantifiable numeric or scale-based measurements that assess a company's effectiveness or success in reaching strategic and operational goals. Examples of are product turnovers, sales by promotion, sales by employee, and earnings per share. LIKE - Correct Answer-In SQL, a comparison operator used to check whether an attribute's text value matches a specified string pattern. linking table - Correct Answer-In the relational model, a table that implements an M:M relationship. See also composite entity. logical data format - Correct Answer-The way a person views data within the context of a problem domain. mandatory participation - Correct Answer-A relationship in which one entity occurrence must have a corresponding occurrence in another entity. For example, an EMPLOYEE works in a DIVISION. (A person cannot be an employee without being assigned to a company's division.) many-to-many (M:N or *..*) relationship - Correct Answer-Association among two or more entities in which one occurrence of an entity is associated with many occurrences of a related entity and one occurrence of the related entity is associated with many occurrences of the first entity. MapReduce - Correct Answer-An open-source application programming interface (API) that provides fast data analytics services; one of the main Big Data technologies that allows organizations to process massive data stores. master data management (MDM) - Correct Answer-In business intelligence, a collection of concepts, techniques, and processes for the proper identification, definition, and management of data elements within an organization. MAX - Correct Answer-A SQL aggregate function that yields the maximum attribute value in a given column. metadata - Correct Answer-Data about data; that is, data about data characteristics and relationships. See also data dictionary. method - Correct Answer-In the object-oriented data model, a named set of instructions to perform an action. represent real-world actions, and are invoked through messages. MIN - Correct Answer-A SQL aggregate function that yields the minimum attribute value in a given column. multidimensional database management systems (MDBMSs) - Correct Answer-A database management system that uses proprietary techniques to store data in matrixlike arrays of n dimensions known as cubes. multidimensional online analytical processing (MOLAP) - Correct Answer-An extension of online analytical processing to multidimensional database management systems. multiuser database - Correct Answer-A database that supports multiple concurrent users. multivalued attributes - Correct Answer-An attribute that can have many values for a single entity occurrence. For example, an EMP_DEGREE attribute might store the string "BBA, MBA, PHD" to indicate three different degrees held. name node - Correct Answer-One of three types of nodes used in the Hadoop Distributed File System (HDFS). The stores all the metadata about the file system. See also client node and data node. nested query - Correct Answer-In SQL, a query that is embedded in another query. See subquery. network model - Correct Answer-An early data model that represented data as a collection of record types in 1:M relationships. non-identifying relationship - Correct Answer-A relationship in which the primary key of the related entity does not contain a primary key component of the parent entity. nonprime attribute - Correct Answer-An attribute that is not part of a key. normalization - Correct Answer-A process that assigns attributes to entities so that data redundancies are reduced or eliminated. NoSQL - Correct Answer-A new generation of database management systems that is not based on the traditional relational database model. NOT - Correct Answer-A SQL logical operator that negates a given predicate. null - Correct Answer-The absence of an attribute value. Note that a null is not a blank. object - Correct Answer-An abstract representation of a real world entity that has a unique identity, embedded properties, and the ability to interact with other and itself. object-oriented data model (OODM) - Correct Answer-A data model whose basic modeling structure is an object. object-oriented database management system (OODBMS) - Correct Answer-Data management software used to manage data in an object-oriented database model. object/relational database management system (O/R DBMS) - Correct Answer-A DBMS based on the extended relational model (ERDM). The ERDM, championed by many relational database researchers, constitutes the relational model's response to the OODM. This model includes many of the object-oriented model's best features within an inherently simpler relational database structure. one-to-many (1:M or 1..*) relationship - Correct Answer-Associations among two or more entities that are used by data models. In a relationship, one entity instance is associated with many instances of the related entity. one-to-one (1:1 or 1..1) relationship - Correct Answer-Associations among two or more entities that are used by data models. In a relationship, one entity instance is associated with only one instance of the related entity. online analytical processing (OLAP) - Correct Answer-Decision support system (DSS) tools that use multidimensional data analysis techniques. creates an advanced data analysis environment that supports decision making, business modeling, and operations research. operational database - Correct Answer-A database designed primarily to support a company's day-to-day operations. Also known as a transactional database, OLTP database, or production database. optional attribute - Correct Answer-In ER modeling, an attribute that does not require a value; therefore, it can be left empty. optional participation - Correct Answer-In ER modeling, a condition in which one entity occurrence does not require a corresponding entity occurrence in a particular relationship. OR - Correct Answer-The SQL logical operator used to link multiple conditional expressions in a WHERE or HAVING clause. It requires only one of the conditional expressions to be true. ORDER BY - Correct Answer-A SQL clause that is useful for ordering the output of a SELECT query (for example, in ascending or descending order). partial dependency - Correct Answer-A condition in which an attribute is dependent on only a portion (subset) of the primary key. participants - Correct Answer-An ER term for entities that in a relationship. For example, in the relationship "PROFESSOR teaches CLASS," the teaches relationship is based on the PROFESSOR and CLASS. performance tuning - Correct Answer-Activities that make a database more efficiently in terms of storage and access speed. physical data format - Correct Answer-The way a computer "sees" (stores) data. portals - Correct Answer-In terms of business intelligence, a unified, single point of entry for information distribution. predicate logic - Correct Answer-Used extensively in mathematics to provide a framework in which an assertion (statement of fact) can be verified as either true or false. primary key (PK) - Correct Answer-In the relational model, an identifier composed of one or more attributes that uniquely identifies a row. Also, a candidate key selected as a unique entity identifier. See also key. prime attribute - Correct Answer-A key attribute; that is, an attribute that is part of a key or is the whole key. See also key attributes. query - Correct Answer-A question or task asked by an end user of a database in the form of SQL code. A specific request for data manipulation issued by the end user or the application to the DBMS. query language - Correct Answer-A nonprocedural language that is used by a DBMS to manipulate its data. An example of a is SQL. query result set - Correct Answer-The collection of data rows returned by a query. record - Correct Answer-A collection of related (logically connected) fields. recursive relationship - Correct Answer-A relationship found within a single entity type. For example, an EMPLOYEE is married to an EMPLOYEE or a PART is a component of another PART. referential integrity - Correct Answer-A condition by which a dependent table's foreign key must have either a null entry or a matching entry in the related table. relation - Correct Answer-A logical construct perceived to be a two dimensional structure composed of intersecting rows (entities) and columns (attributes) that represents an entity set in the relational model. relational database management system (RDBMS) - Correct Answer-A collection of programs that manages a relational database. The software translates a user's logical requests (queries) into commands that physically locate and retrieve the requested data. relational diagram - Correct Answer-A graphical representation of a relational database's entities, the attributes within those entities, and the relationships among the entities. relational model - Correct Answer-Developed by E. F. Codd of IBM in 1970, the is based on mathematical set theory and represents data as independent relations. Each relation (table) is conceptually represented as a two dimensional structure of intersecting rows and columns. The relations are related to each other through the sharing of common entity characteristics (values in columns). relational online analytical processing (ROLAP) - Correct Answer-Analytical processing functions that use relational databases and familiar relational query tools to store and analyze multidimensional data. relational schema - Correct Answer-The organization of a relational database as described by the database administrator. relationship - Correct Answer-An association between entities. relationship degree - Correct Answer-The number of entities or participants associated with a relationship. A relationship degree can be unary, binary, ternary, or higher. repeating group - Correct Answer-In a relation, a characteristic describing a collection of multiple entries of the same type for a single key attribute occurrence. For example, a car can have multiple colors for its top, interior, bottom, trim, and so on. required attribute - Correct Answer-In ER modeling, an attribute that must have a value. In other words, it cannot be left empty. role - Correct Answer-In Oracle, a named collection of database access privileges that authorize a user to connect to a database and use its system resources. roll up - Correct Answer-To aggregate data into summarized components, that is, higher levels of aggregation. roll up - Correct Answer-In SQL, an OLAP extension used with the GROUP BY clause to aggregate data by different dimensions. the data is the exact opposite of drilling down the data. ROLLBACK - Correct Answer-A SQL command that restores the database table contents to the condition that existed after the last COMMIT statement. router - Correct Answer-Hardware/software equipment that connects multiple and diverse networks. router - Correct Answer-An intelligent device used to connect dissimilar networks. rules of precedence - Correct Answer-Basic algebraic rules that specify the order in which operations are performed. For example, operations within parentheses are executed first, so in the equation 2 + (3 * 5), the multiplication portion is calculated first, making the correct answer 17. schema - Correct Answer-A logical grouping of database objects, such as tables, indexes, views, and queries, that are related to each other. Usually, a belongs to a single user or application. second normal form (2NF) - Correct Answer-The second stage in the normalization process, in which a relation is in 1NF and there are no partial dependencies (dependencies in only part of the primary key). secondary key - Correct Answer-A key used strictly for data retrieval purposes. For example, customers are not likely to know their customer number (primary key), but the combination of last name, first name, middle initial, and telephone number will probably match the appropriate table row. See also key. segment (SEGM) - Correct Answer-In the hierarchical data model, the equivalent of a file system's record type. semistructured data - Correct Answer-Data that has already been processed to some extent. set theory - Correct Answer-A part of mathematical science that deals with sets, or groups of things, and is used as the basis for data manipulation in the relational model. simple attribute - Correct Answer-An attribute that cannot be subdivided into meaningful components. Compare to composite attribute. single-user database - Correct Answer-A database that supports only one user at a time. single-valued attribute - Correct Answer-An attribute that can have only one value. slice and dice - Correct Answer-The ability to focus on distinct sections of a data cube (drill down or roll up) to perform a more detailed analysis. social media - Correct Answer-Web and mobile technologies that enable "anywhere, anytime, always on" human interactions. sparsity - Correct Answer-In multidimensional data analysis, a measurement of the data density held in the data cube. strong (identifying) relationship - Correct Answer-A that occurs when two entities are existence-dependent; from a database design perspective, this exists whenever the primary key of the related entity contains the primary key of the parent entity. strong entity - Correct Answer-An entity that is existence-independent, that is, it can exist apart from all of its related entities. Also called a regular entity. structural dependence - Correct Answer-A data characteristic in which a change in the database schema affects data access, thus requiring changes in all access programs. structural independence - Correct Answer-A data characteristic in which changes in the database schema do not affect data access. structured data - Correct Answer-Data that has been formatted to facilitate storage, use, and information generation. Structured Query Language (SQL) - Correct Answer-A powerful and flexible relational database language composed of commands that enable users to create database and table structures, perform various types of data manipulation and data administration, and query the database to extract useful information. subquery - Correct Answer-A query that is embedded (or nested) inside another query. Also known as a nested query or an inner query. subschema - Correct Answer-The portion of the database that interacts with application programs. SUM - Correct Answer-A SQL aggregate function that yields the sum of all values for a given column or expression. superclass - Correct Answer-In a class hierarchy, the superclass is the more general classification from which the subclasses inherit data structures and behaviors. superkey - Correct Answer-An attribute or attributes that uniquely identify each entity in a table. See key. table - Correct Answer-A logical construct perceived to be a two dimensional structure composed of intersecting rows (entities) and columns (attributes) that represents an entity set in the relational model. ternary relationship - Correct Answer-An ER term used to describe an association (relationship) between three entities. For example, a DOCTOR prescribes a DRUG for a PATIENT. third normal form (3NF) - Correct Answer-A table is in when it is in 2NF and no non- key attribute is functionally dependent on another non-key attribute; that is, it cannot include transitive dependencies. transitive dependency - Correct Answer-A condition in which an attribute is dependent on another attribute that is not part of the primary key. tuple - Correct Answer-In the relational model, a table row. unary relationship - Correct Answer-An ER term used to describe an association within an entity. For example, an EMPLOYEE might manage another EMPLOYEE. Unified Modeling Language (UML) - Correct Answer-A language based on object- oriented concepts that provides tools such as diagrams and symbols to graphically model a system. unique index - Correct Answer-An index in which the index key can have only one associated pointer value (row). unstructured data - Correct Answer-Data that exists in its original, raw state; that is, in the format in which it was collected. UPDATE - Correct Answer-A SQL command that allows attribute values to be changed in one or more rows of a table. versioning - Correct Answer-A property of an OODBMS that allows the database to keep track of the different transformations performed on an object. very large databases (VLDBs) - Correct Answer-Database that contains huge amounts of data—gigabyte, terabyte, and petabyte ranges are not unusual. weak entity - Correct Answer-An entity that displays existence dependence and inherits the primary key of its parent entity. For example, a DEPENDENT requires the existence of an EMPLOYEE. weak relationship - Correct Answer-A relationship in which the primary key of the related entity does not contain a primary key component of the parent entity. website - Correct Answer-Refers to the Web server and the collection of Web pages stored on the local hard disk of the server computer. WHERE - Correct Answer-A SQL clause that adds conditional restrictions to a SELECT statement that limit the rows returned by the query. wildcard character - Correct Answer-A symbol that can be used as a general substitute for: all columns in a table (*) when used in an attribute list of a SELECT statement or, zero or more characters in a SQL LIKE clause condition ( % and _ ). workgroup database - Correct Answer-A multiuser database that usually supports fewer than 50 users or is used for a specific department in an organization.