slide session 11 - databases

database

a collection of data organized for search and retrieval (not necessarily on a computer)

• relies on standards for storage and retrieval of info

where databases are used

everywhere!
- all dynamic websites use them

• enterprise systems are big databases

• all records management functions

relational databases

the dominant approach to structuring databases for over 40 years

• the primary data structure is the table

• tables are related based on certain types of shared data (keys)

entity

a class of people/places/objects/events/concepts where we need to capture/store data for

• represented by tables

instance

a single occurrence of an entity

• the records within a table indicate ___(s) of an entity

attribute

a descriptive property or characteristic of a property

• indicated by the columns in a table

• a data entity has a data ___

• also known as element, property, field, etc

primary key

an attribute that assumes a unique value for each instance

• also known as a unique identifier

• every instance has one

operational databases

support day-to-day operations for an information system

• also known as transactional databases

personal databases

databases created or maintained by individuals

work group databases

databases created or maintained by teams.

data warehouses

large data repositories that store data extracted from other databases

key integrity

no two records in a table have the same primary key

• a type of data integrity

domain integrity

making sure the right kind of data is being entered for. various attributes/fields

• a type of data integrity

referential integrity

ensuring that foreign keys in one table correspond to a primary key in another table

• a type of data integrity

big data

data sets so large that they exceed the processing
capacity of conventional/relational database systems

• three v’s of ____: volume, velocity, and variety

• no single size qualifier for what makes data big (terabyte, petabyte, etc)

• largely unstructured

volume

dealing with terabytes, petabytes, and exabytes of data

velocity

using data as it streams into the org

variety

all different kinds of data are included (structured vs.
unstructured, text vs. multimedia, etc)

sources of big data

• social media

• sensor networks

• public web

• documents

• traditional databases

structured data

data that is organized in a predefined data model; the kind
you can capture in a relational database

• sales transactions, personnel records, census records, etc

unstructured data

data that’s not organized in a pre-defined way; doesn’t fit an established data model

• images, audio/video files, text messages, word files, etc

• can’t be easily analyzed using prevailing databased technologies

big data technologies

• noSQL databases

• mapreduce

• hadoop

• hive

• pig

• machine learning