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Information Systems and Business Processes

• A business process involves a sequence of activities aimed at producing a service or product by using material, organizational, and informational resources.
• An information system is a set of data managed by business processes.
• An information system contains data assets, a set of procedures for data handling, human resources to oversee these procedures, and tools for information storage and processing.

Information System Components and Computer Systems

• Information systems within an organization components store, share, process, acquire, retrieve, and transmit data.
• The main components include human resources, data assets, automated/non-automated tools, and procedures.
• A computer system is the technology—hardware, software, and databases/management systems—that supports the information system, including communication networks.
• A company transforms into an organization, that is supported by an information system (with people/employees/major roles), that connects to a computer system for automatic management.

Information Production and Example System

• Information production flows through events, data acquisition, processing, and transmission, information flow then results.
• An example information/computer system includes a municipality's system for smog detection.
• The information system involves people and procedures for managing pollution-related info.
• The computer system manages smog level data automatically using hardware, software, and the network.

Data and Elementary Information

• Computer systems need technology to process data and produce information through automated programs.
• Organizational information is stored as data on media, needing interpretation to become actual information.
• Data represents information for storage/management purposes.
• Raw data paired with interpretation rules is stored as data.
• Elementary information includes an attribute, its data type, and its specific value.

Complex Information and Databases

• Complex information is the result of logically related elementary bits.
• Interactions with databases include shopping, purchases with credit cards, insurance payments, and enrolling in courses.
• Using data collections that are persistently stored, related to real-world situations, and serve to help organizations.
• Databases are organized collections of data that has related information.
• A database is a tool that lets users work consistently with data; it's a shared repository of data.

Database Descriptions and DBMS

• A database includes a catalog of data about the data.
• A DBMS is a software layer that efficiently manages all data operations.
• A DBMS is a set of programs that defines data types/structures/constraints, manipulates data (insert/delete/update/retrieve), and controls/protects data access.
• DBMS simplifies database usage, handling all operations the applications used to have to do themselves.

Database Systems and Approaches Using DBMS

• The applications that interact with the database are simplified.
• Database systems, like phone books, can be managed with specific programs using a personal approach.
• Alternatively, a DBMS product facilitates data definition and management through operations like SELECT, INSERT, DELETE, and UPDATE.
• A database system consists of a database and a DBMS.

ANSI/SPARC Three-Level Architecture

• The ANSI/SPARC architecture focuses on isolating data from the applications that use them and supporting data independence with 3 levels.
• A database has conceptual and physical schemas.

External Level

• The external level provides user-specific data views.
• Users can see the same data in different ways.
• Access is restricted for security, by applying the data view.

Conceptual Level

• The conceptual level describes the logical organization of data, defining tables, relations, and constraints.
• Using the conceptual level ensures logical independence.

Internal Level and Data Independence

• The internal level describes how data is stored physically, ensuring physical data independence.
• Logical Data Independence means you can alter the database structure without altering the programs that interact with it.
• Physical Data Independence means that the storage implementation can be altered without altering structure.

Online Library System and Levels

• The External Level, or user view, shows students book titles/authors/availability, librarians student records/loans/due dates, and admins have access to settings.
• The Conceptual Level, defining the database, outlines tables such as Books, Users, and Loans.
• The internal level manages data storage by using binary, indexes, and optimized file storage.

History of DBMS

• Hierarchical (1960s): data in hierarchies.
• Reticular (1970s): organizes through graph data structures.
• Relational (late 1970s): data into related records.
• Object-oriented: data in software objects with links.
• Object-relational: is relational but broadens structure.
• It supports tables and also mixes object-oriented features.

Not Only SQL (NoSQL) Models and DBMS Functionality

• DBMS functionality includes defining data organization through DDL and enabling data query/management via DML (INSERT, UPDATE, DELETE).

DBMS Transactions

• DBMS executes transactions, which is a user program in a DBMS, where it commits (ends as wanted) or aborts (returns to the previous state).

Transactions

• Operations include SELECT, INSERT (new object), UPDATE (modify object), and DELETE (remove object) and all have [ACID] properties.
• [A] = atomicity, being fully executed or not at all.
• [C] = consistency, maintaining the same state of the database.
• [I] = isolation, independent execution of each transaction.
• [D] = durability, making committed transactions' effects permanent for future recording.

DBMS Features

• Redundancy/consistency checks removes duplicates & reduces the risk of data inconsistencies.
• Data in organizations can be shared users and apps via sharing.
• Data Integrity: DBMS manages changes via constraint rules.
• Efficient management of operations: features enable efficient queries/updates.
• Concurrency Control: DBMS ensures concurrent transactions without interference.
• Reliability: restores databases after failures/malfunctions.
• Security: avoids unathorised access.

Main Components of a DBMS

• Access Manager: grants access to authorized users.
• Query Manager: runs DDL/DML, converting to DBMS instructions.
• Memory Manager: manages info access in memory.
• File Manager: controls file management on mass storage.
• Integrity Manager: checks the integrity within a database.
• the Concurrency control manager manages simultaneous transactions to share database resources.
• Reliability manager handles saving operations.

Operational Support Systems

• Handles management in B2B, in-company, or B2C scenarios. Their functions include the management of business strategies, processing of transactions, ops planning/control, and admin.
• Information handled by these processes can describe objects & actors, transactions, and operations planning (production plan of an org). This data can remain stable, changeable, or related (airline bookings).

Order Management Systems

• In Purchasing, data is gathered (info acquisition), stored, processed, and communicated to determine order fulfillment. These consist of equipment and people.

Monitoring and Control Systems

• These applications include monitoring (smog levels), structures (bridges), surveillance, and control of production.
• More activities also include medical, access, and traffic data

Environmental and Surveillance Systems

• Environmental systems use units/sensors to get smog data, transmitting it across networks to servers/databases. The employees then process and give data (info processing) and the major details to the appropriate people (info communication).
• In surveillance systems, cameras acquire data (info acquisition), storing this on servers (info storage), to then be processed via live software (info processing). Operators will report it to law enforcement officials in cases of issues.

Information Systems in Public Administration

• Information systems in public administration support agriculture, healthcare, education, and justice and it is important to manage everything.
• Aspects of document management involve organizational and archival matters, the system consists of acquired documents.

Document Management Macro and Hospital Objectives

• Macro objectives for document include reliably producing documents for legal use, processing documents, and maintaining documents, to then transmit authentic documents and speed up retrieving documents.
• A hospital information system, composed of medical, administrative, and financial subsections, manages all data to support hospital functions (clinical, medical, and research efforts). Other models are airport applications.

Intro To R

• R is a package for data analysis, with data handling, operators, graphing functions, and packaging.

R Comments and Computations

• Using a question mark will display help text for functions.
• R uses # for comments.
• The "rm" command removes variables.
• Commands like "install.packages()" search and download packages.
• Objects have values assigned via "<-" or "=" and arithmetic/logic can be done in variables.
• Vector construction can be done with the "c()" function.

Vector Access, Missing Values/Importing

• Values within the vector are indexed using brackets (ex. Vectora[1]). "NA" has to do with missing data, and it also has an argument in cases with NA values (ex. na.rm).
• The Vectors can be created with Cbind() and the command getwd() gets the working directory.
• In the correct importing data, code looks like (BirdDF <- read.csv(BirdData.csv), header = TRUE)). By default a data frame, and column titles offer access to the data.

Datatypes

• Datatypes have functions named as.matrix() and as.data.frame().

Other R Concepts

• Plot data with the "plot()" function. Multiplying plots display with "par()".
• R is an interpreted language - commands execute without compilation
• R has parentheses, plots(), and sum().
• Operations, result objects can be done directly in the software using the active memory, including arithmetic and logical evaluations.

Variables and Data Types

• Objects in R contain modes ("numeric", "character", "complex", "logical")
• They also contain length, with the use of mode() or length() functions.
• Missing data is "NA", and character entries are double quotes ("").

R Objects

• A vector is a variable with the admitted arguments mode and length
• A factor is a categorical variable
• An array is dimensioned in particular sizes, while being an organized table
• dataframes, timseries, and lists contain multiple data types
• vector's mode & length should be described

Additional Factors

• "dm" shows the dimension of an object.
• A matrix with two rows and two columns are read as [dm 2,2], that is, length 4.
• reading/writing and discovering the directory involve getwd().

Dataframes

• Dataframes work with read.table and also create.
• The codes in the datafiles have arguments like if the code contains names for the variables.
• The scanning in databases is easier with scan is more flexible.

Regular Sequences

• Regular Sequences can be made using the colon and seq() functions are used to generate range.
• A "rep" function can be used for vectors with repeated elements; "gl" code is used to generate factors, which is very useful when applied..

Random and Empty Data

• Statistic is useful, and randoms can be generated using Runif and Rnorm.
• "It is possible" to declare and modify the mode of code.

R Statistics

• Factors include values and different levels. Code to find factors includes sort(unique(x), na.last = TRUE). If none, there are zero factor levels. All have three functions, these being Numeric(), Logical(), and Character.

Data Frame

• Create a dataframe with read-table function. To create a frame with the function data.frame(), you need to declare the X, N, and M characteristics. It also contains commands that change the column.