Database Chapter 1

Data
Raw facts, or facts that have not been processed to reveal their meaning to the end user.
Database
A shared, integrated computer structure that houses a collection of related data. Contains two types of data: end-user data (raw facts) and metadata
DBMS – (Database Management System)
Manages the data, provides security, a means of accessing data from in the database.
Database System
An organization of components that defines and regulates the collection, storage, management, and use of data in a database environment.
Database Catalog
Consists of metadata in which definitions of database objects are stored
-such as base tables, views (virtual tables), synonyms, value ranges, indexes, users, and user groups.
Program-data Independence
The separation of the logical (conceptually organizes and understands data) and physical views (how and where the data are physically arranged and stored on a disk, tape, or other media) of data
User View
Subset of the database that contains virtual data derived from the database files but is not explicitly stored.
Database Administrator (DBA)
Job title focused on directing, performing, or overseeing activities associated with a database or set of databases.
End user
A person or system that directly interacts with the solution.
Canned transaction
Standard types of queries and updates that have been carefully programmed and tested.

Mostly used by Naive users to perform actions on the database related to their needs.

Deductive database system
Provides capabilities for defining deduction rules; inferencing new information from the stored database facts
Persistent object
a specialized object that has the property of continuous state, which means it is available at all times
Meta-data
Data associated with an object, supplementing the object’s file system data.
Transaction-processing application.
A management information system designed to handle large volumes of routine, recurring transactions.
What are the four main types of database actions?
selection,updating,deleting,inserting.
What are the main characteristics of the database approach and how it differs from traditional file systems.
DATABASE:
• Self-describing nature of a database system
• Insulation between programs and data, and data abstraction
• Support of multiple views of the data
• Sharing of data and multi-user transaction processing

FILE SYSTEM:
• Approach to the file system, each user is defined as necessary to implement the file, to perform a specific application

What are the different types of database end users?
Casual, Naïve/parametric, Sophisticated, Standalone
Casual end users
People who use a database query language to access a database, but do not develop applications.
Naïve/parametric end users
Constantly querying and updating the database, using standard types of queries and updates that have been carefully programmed and tested.
Sophisticated end users
Engineers, scientists, etc who are experts at using the DB, and develop applications on top of a databases.
Standalone end users
Maintain personal databases by using ready-made program packages that provide easy-to-use interfaces.
What are the capabilities of a Database Management System?
• Provides a way to organize data as records, tables, or objects
• Accepts data input
• Provides query languages – for searching, sorting, reporting…etc.
• Provides multi-user access to data – with security features that prevent some users from viewing/changing info
• Provides data integrity features – prevents more than one user from accessing and changing the same info
• Provides a data dictionary (metadata) – that describes the structure of the database, related files, and record information
Discuss the differences between database systems and information retrieval systems.
• Database systems work with relational databases(well structured data) – use relational tables with well defined values for each row and column.
• Information retrieval system works on unstructured data(raw textfiles/documents). IR system uses an Inverted index which is the index of {term,docIDs} entries. For each term there is a corresponding list of documents in which the term is present.