Week 2 Flashcards
What are BI systems enhanced with?
Additional visualizations, alerts and performance measurements capabilities
What is BI an evolution of and what is the difference between now and the past with usage?
BI is an evolution of decision support concepts over time, now everybody can use information systems where before these were only for executives.
What is the main objective of BI?
The main objective is to enable easy access to data and business managers to analyze it.
What does BI help with?
It helps to transform data into information, to improve decisions, and finally to implement action.
What are the 4 components of BI systems?
- Data warehouse with source data
- Business analytics (tools)
- Business performance management (BPM) = monitoring & analyzing performance
- A user interface (dashboard)
Who/what is DSS oriented towards and who is BI oriented towards?
DSS towards analysts
BI towards executive and strategy orientation
What kind of solution does DSS result in?
A customized solution for very unstructured problems
What is OLTP (online transaction processing)
Term used for transaction processing systems such as ERP, CRM, POS etc. for capturing and storing data.
What are OLTP (online transaction processing) used for?
OLTP is used to process routine operational business tasks and focus on processing and recording data in operational database systems.
What is OLAP (online analytical processing) and what is it used for?
OLAP is used for converting data into information for decision support. Focus is on analyzing data stored in a data warehouse through data cubes, drill-down / rollup, slide & dice etc.
What is an OLAP Cube?
A Cube in OLAP is a multidimensional data structure (actual or virtual) that allows fast analysis of data.
What is the list of OLAP operations?
Slice
Dice
Drill down/up
Roll up
Pivot
What is slice?
subset of a multidimensional array (multiple years + categories –> 1 year + categories)
What is dice?
A slice on more than two dimensions
What is drill down/up
navigating among levels of data
What is roll up?
Computing all of the data relationships for one or many dimensions.
What is Pivot?
Used to chance the dimensional orientation of a report or an ad hoc query-page display.
What 3 elements is Business Analytics usually categorized as?
Descriptive analytics
Predictive analytics
Prescriptive analytics
What is Big Data?
Big Data is the information asset characterized by such high volume, velocity and variety to require specific technology and analytical methods for its transformation into value.
What can a Data scientist do?
a data scientist can use big data to make discoveries and bring structure to data. They make analysis possible.
What is a database?
A shared computerized structure that captures, stores and relates data.
What is a database system?
A system of hardware, software, people, procedures and data that allow the capture, storage, management and use of data within a database environment.
What is a database management system (DBMS)
A group of programs that manipulate the database and provide the interface between the database and the user as well as other application programs.
What are the advantages of database systems?
- Data integration
- Data sharing
- Minimizing data redundancy and data inconsistency
- Data independence (seperate programs)
- Cross-Functional Analysis
What is a data warehouse?
A physical repository where relational data are specially organized to provide enterprise-wide, cleansed data in a structured format.
What describes data warehouses?
The data warehouse is a collection of integrated, subject-oriented databases designed to support DSS functions, where each unit of data is non-volatile and relevant to some moment in time.
What is a Data Mart?
A departmental small scale “DW” that stores only limited/relevant data.
What is the difference between a dependent and independent data mart?
Dependent: subset directly from DW
Independent: small DW for specific part of company
What is ETL?
Data Extraction, transformation and Load.
The purpose of ETL is to load the warehouse with integrated and cleansed data.
What does the succes of LAP and data mining tools depend on?
OLAP and data mining tools rely on how well the data are transformed.
What may performing extensive transformation be a sign of?
Performing extensive transformation may be a sign of poorly managed data and a fundamental lack of a coherent data management strategy.
What are Data Lakes?
A system or repository of data, a single store of all enterprise data including raw copies of source system data. Used for tasks as reporting, visualization, analytics and machine learning.
What are relational databases?
Datatables represent entity types. The tables are related or connected to each other through common fields that appear in two or more tables.
What is metadata?
Data that describes other data?
What is syntactic metadata?
Data describing the syntax of data (dictionary)
What is structural metadata?
Data describing the structure of data (grammar book)
What is semantic metadata?
Describing the meaning of data in a specific domain (encyclopedia)
What is the data hierarchy?
- Database
- Entity set (Table/file)
- Tuple (Row/Record)
- Attribute (Column/Field)
What is a spreadsheet?
Storage of data in tables with two dimensions
What are database tables?
Databases store data in multiple tables that are related to each other via primary and foreign key relationships.
What 3 points describes a primary key?
- Each database table must have a primary key
- This is a unique identifier for each record in a database table
- The unique identifier is required to be able to identify and retrieve the records.
What describes a Foreign key?
- An attribute in one table that is a primary key in another table
- used to link two tables
- Ensure referential integrity.
What are the main themes of big data?
Information, technology, methods and impact.
What is the fundamental fuel of the big data phenomenom?
Information, not data
What is Hadoop?
An open source framework that was specifically designed to deal with Big Data in a satisfactory manner.
What is DQL?
Data query language
What is DML?
Data manipulation Languange
What is DDL
Data Definition Language
What is the order of database elements from smallest to largest?
Data element, record, file, database
