Chapter 4: Relational Databases and Enterprise Systems

disadvantages of hosting enterprise systems in the cloud?

-ensuring that sensitive data is secure and backed up frequently -making sure the host has minimal down time and adequate processing speed at all times -constant internet connnection

What challenges do organizations face when implementing an enterprise system?

1) integrating various modules within the enterprise system 2) Integrating with external systems such as the information system of a supplier and/or customer 3) Integrating with the firm's own existing legacy systems 4) converting data from existing legacy systems to the enterprise system 5) Getting any big project implemented at a firm

Explain the difference among hierarchal, network, and relational data models. What makes the relational data model most popular data model in use today?

Hierarchical data models organize data into a tree-like structure. In a hierarchical data model, data elements are related to each other using one-to-many relationships. A network data model is a flexible model representing objects and their relationships. It allows many-to-many relationships. The relational data model is a data model that stores information in the form of related two-dimensional tables. While hierarchical and network data models require relationships to be formed at the database creation, relational data models can be made up as needed. The relational database is the most popular data model in use today because it has the following advantages: flexibility and scalability simplicity reduced information redundancy.

What are the basic requirements of a relational database?

The approach of relational database imposes requirements on the structure of tables: • The Entity Integrity Rule: the primary key of a table must have data values (cannot be null). • The Referential Integrity Rule: the data value for a foreign key must either be null or match one of the data values that already exist in the corresponding table. • Each attribute in a table must have a unique name. Copyright © 2018 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 1 Richardson, Chang, Smith - Accounting Information Systems, 2nd Edition - Chapter 4 • Values of a specific attribute must be of the same type. • Each attribute (column) of a record (row) must be single-valued. This requirement forces us to create a relationship table for each many-to-many relationship. • All other non-key attributes in a table must describe a characteristic of the class (table) identified by the primary key.

Structured Query Language (SQL) is used to retrieve data from a database. Why would an accountant need to learn SQL?

The information accountants needed is not always ready for use in the database. Accountants need to use SQL to pull data needed out from the master table, to design queries to get the calculated data and to run report in an application. Additionally, learning SQL helps accountants better communicate with IT support when they need assistance.

databases

a collection of related data for various uses

simplicity

a relational data model is a realistically simple model that is easy to communicate to both database users and database developers

reduced information redundancy

a relational data model requires each piece of data to be recorded only in one place, eliminating the need for information to be stored in multiple places in the organization. This also helped keep the information updated because the information only has to be updated once in one database, which can help avoid data inconsistency

flexibility and scalability

as business and informational requirements change, relational data models are able to handle these changes quickly and easily. For this flexibility, the relational data model for databases is the most popular data model today/

relation data model

data model that stores information in the form of related two-dimensional table. It allows designers and users to identify relationships at the time the database is created or much later whenever new information requirements from the data model is desired

network data model

flexible model representing objects and their relationships. Allows each record to have multiple parent and child records or M:N mapping, also known as many to many relationships.

database management system (DBMS)

is defined as a computer program that creates, modifies, and queries the database. Specifically, the DBMS is designed to manage a database's storage and retrieval of information

hierarchical data models

organized data into a tree-like structure that allows repeating information using defined parent/child relationships. Using a one-to-many.

referential integrity rule

the data call for a foreign key must either be null or match one of the data values that already exist in the corresponding table

data dictionary

the data dictionary describes the data fields in each database record such as field description, field length, field type (e.g., alphanumeric, numeric), and so o.

database administrator

the database administrator is responsible for the design, implementation, repair, and security of a firm's database

entity integrity rule

the primary key of a table much have data value (cannot be null)