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DATABASE TECHNOLOGY

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WHAT IS DATABASE TECHNOLOGY?

The essential feature of database technology is that it provides an INTERNAL Representation (model) of the EXTERNAL world of Interest.

The TECHNOLOGY involved is concerned primarily with maintaining the internal representation consistent with external reality; this involves the results of extensive R&D over the past 30 years.

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DATABASE

Definition: A database is a collection of

records or Data that is stored in a computer system. The structure of a database is dependent on how the data is organized, according to a particular database model. Today we commonly use a relational database model. Other models include a hierarchical model and the network model.

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SIMPLE APPROACHES TO DATA MANAGEMENT

There are several ways to manage dataSoftware packages.Personal information managers.Handheld devices.Home budget software.

Database approach Increased flexibility in the use of

dataRequires a database management

system (DBMS)

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THE DATABASE APPROACH TODATA MANAGEMENT

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DATABASE DESIGN Field design

Numeric field Alphanumeric Date Logical piece of data

Computed field Record and table design Record Table

In any database, you must Identify the exact fields for each record Identify the types of records for each table

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DATABASE DESIGN

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CREATING AND MODIFYING A DATABASE

Typical uses of a data dictionaryProvide a standard definition of terms and data

elements that can be referenced by programmers, database administrators, and users to maintain data integrity.

Simplify database modification.

The data dictionary helps achieve the advantages of the database approach by• Reducing data redundancy. Increasing security.

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CREATING AND MODIFYING A DATABASE

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UPDATING A DATABASE

Databases are updated by adding, modifying, or deleting recordsEssential to maintain data accuracy and integrityFront-end applications can be used to enter changes

which are then transferred to the database

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UPDATING A DATABASE

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MANIPULATING DATA AND GENERATING REPORTS

Data manipulation language (DML)

Query by example (QBE)

Structured Query Language (SQL)

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MANIPULATING DATA AND GENERATING REPORTS

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DATABASE BACKUP AND RECOVERY

Database backup

Database recovery

Redundant array of independent disks (RAID)

Storage area network (SAN)

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USING DATABASE SYSTEMS IN ORGANIZATIONS

Organizations need to process routine transactions

Routine processing activities Pay employees. Send out bills to maintain a healthy cash

flow. Send out a monthly newsletter Pay suppliers for parts and raw

materials.

Information and decision support Valuable tool to support decision making.

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DATA WAREHOUSES, DATA MARTS,AND DATA MINING

Data warehouse

Data mart

Data mining

Business intelligence

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DATA WAREHOUSES, DATA MARTS,AND DATA MINING

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TRENDS – DISTRIBUTED DATABASES

Distributed database• Also called a virtualized databaseActual data may be spread across several databases at

different locations, allow more users direct access at different user sites

Replicated databaseDatabase that holds a duplicate set of frequently used

data

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TRENDS – DISTRIBUTED DATABASES

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DATABASE SYSTEMS, THE INTERNET,AND NETWORKS

Databases are typically used to organize and deliver Web data and information.

Internet access to databases allows collaboration. Security is a concern

According to the text, some security experts believe that up to 40 percent of Web sites that connect to corporate databases are susceptible to letting hackers take complete control of the database.

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DATABASE SYSTEMS, THE INTERNET,AND NETWORKS

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VISUAL, AUDIO, UNSTRUCTURED,AND OTHER DATABASE SYSTEMS

Organizations are finding needs to store visual and audio data.Music companies

Drug companies.

Law enforcement.

Unstructured database.

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VISUAL, AUDIO, UNSTRUCTURED,AND OTHER DATABASE SYSTEMS

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CONCLUSION

The future will call for efficient handling of objects and sophisticated Web serving. 

Simple Web serving is a feature of most systems and should not pose problems - Object storage will be interesting to watch - especially as the demand ramps up for libraries to store and deliver more and more images, digitised texts, and video etc.

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