WGU c170 THE STRAIGHT TO THE POINT INFORMATION TECHNOLOGY USED QUESTIONS AND THEIR VERIFIED ANSWERS GRADED +

WGU c170 THE STRAIGHT TO THE POINT INFORMATION TECHNOLOGY USED QUESTIONS AND THEIR VERIFIED ANSWERS GRADED + The ____________________ command is used to restore the database to its previous condition. - Answer ROLLBACK; According to the rules of precedence, which of the following computations should be completed first? - Answer Performing operations within parentheses Boyce-Codd Normal Form (BCNF) - Answer A special type of third normal form (3NF) in which every determinant is a candidate key. A table in BCNF must be in 3NF. 4NF - Answer 3NF and no independent multivalued dependencies that produce numerous nulls or redundancy denormalization - Answer yeilds less I/O --> ^ processing speed DB updates less efficient indexing cumbersome data redundancies --> data anomalies Data Definition Language (DDL) - Answer DBMS language that builds the data dictionary, creates the database, describes logical views, and specifies record or field security constraints Data Manipulation Language (DML) - Answer DBMS language that changes database content, including data element creations, updates, insertions, and deletions SELECT, INSERT, UPDATE, DELETE, COMMIT, ROLLBACK WHERE - Answer can be used with SELECT, UPDATE, DELETE in DDL Aggregate Function - Answer COUNT, MIN, MAX, AVG are this type of special function that performs arithmetic computations over a set of rows Used with GROUP BY HAVING - Answer GROUP BY is restricted by this ORDER BY - Answer clause that is used to sort the output of SELECT statement in ascending or descending Join - Answer operation that is performed every time you specify two or more tables in the FROM clause and use a join condition in the WHERE *if you forget this /Cartesian prodct/ automatically used* Operational Data - Answer structured for fast and reliable transaction processing not for decision support Decision Support Data - Answer differs from operational data in 3 ways: time span, granularity, dimensionality Data warehouse - Answer read-only database optimized for data analysis and query processing data mart - Answer small, single-subject data warehouse subset that provides decision support to a small group of people volume, velocity, variety - Answer 3 Vs of Big Data DBs Abstract data type - Answer data type that describes a set of similar objects with shared and encapsulated data representation and methods used to describe complex objects analytical database - Answer db focused primarily of storing historical data and business metrics used for tactical or strategic decision making cascading order sequence - Answer a nested ordering sequence for a set of rows, such as a list in which all last names are alphabetically ordered and, withing the last names all first names are ordered class - Answer a collection of similar objects with shared strx (attr) and behavior (methods) encapsulates obj data rep and a method's implementation organized in a hierarchy class diagram - Answer diagram used to rep data and their rlxns in UML obj notation conceptual model - Answer provides global view of an entire DB and describes the main data obj, avoiding details conceptual schema - Answer rep of the conceptual model, usually expressed graphically COUNT - Answer SQL aggregate fxn that outputs number of rows containing not null vals for a given col or expression sometimes used with DISTINCT data anomaly - Answer data abnormality which inconsistent changes have been made to DB data cube - Answer based on x-, y-, z-axes; static (no ad hoc queries allowed) data node - Answer one of the 3 types of nodes in Hadoop Distributed File System that stores fixed-size data blocks (that can be replicated) derived attribute - Answer attr that does not physically exist within the entity and is derived via an algorithm dimension tables - Answer In a data warehouse, tables used to search, filter, or classify facts within a star schema domain - Answer in data modeling, the construct used to organize and describe an attr set of possible vals enitity relationship diagram (ERD) - Answer reps ERM ents, attr, rlxns Entity relationship model - Answer 1:1, 1:M, M;N model Extensible Mark - Answer meta-lang used to rep and manipulate data elements field - Answer alphabetic or numeric char group or group of char that definsed a char of a noun file - Answer named collection of related records granularity - Answer level of detail rep by the vals stored in a table's row; lowest level --> atomic GROUP BY - Answer SQL clause used to create frequency dists when combined with any of the aggregate fxn in SELECT statement Hadoop - Answer java based, OSource, high speed, fault-tolerant dist storage and computational framework uses low-cost hardware to create clusters of thousands of comp nodes to store and process data Hadoop Distributed File System (HDFS) - Answer highly dist, falut-tolerant, file storage syst designed to manage lg amounts of data at high speeds islands of information - Answer in the old file system environment, pools of independent, duplicated, inconsistent data created and managed by diff depts linking table - Answer in the relational model, a table that implements an M:M rlxn MapReduce - 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. MDBMSs (multidimensional; online --> MOLAP) - Answer database mgmt sys that used proprietary techniques to store data in matrixlike arrays of n dimensions known as cubes nonprime attribute - Answer atrr that is not part of a key normalization - Answer process that assigns attr to entities so that data redundancies are reduced or eliminated predicate logic - Answer used in math to provide a framework in which an assertion (statement or fact) can be verified as either T/F recursive relationship - Answer rlxn found within a single entity type roll up - Answer (1) To aggregate data into summarized components, that is, higher levels of aggregation. (2) In SQL, an OLAP extension used with the GROUP BY clause to aggregate data by different dimensions. Rolling up the data is the exact opposite of drilling down the data. segment (SEGM) - Answer in the hierarchical data model, the equivalent of a file system's record type set theory - Answer part of math science that deals with sets, or groups of things, and is used as the basis for data manipulation in the relational model simple attr - Answer opposite of composite attr slice and dice - Answer the ability to focus on slices of a data cube (drill down or roll up) to perform a more detailed analysis sparsity - Answer in mulitdimensional data analysis, a measurement of the data density held in the data cube versioning - Answer prop of OODBMS that allows the DB to keep track of diff transformations performed on a