itm

1. DATABASE
TECHNOLOGY
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2. 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. 2

3. 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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4. SIMPLE APPROACHES TO DATA
MANAGEMENT
 There are several ways to manage data
 Software packages.
 Personal information managers.
 Handheld devices.
 Home budget software.
 Database approach
 Increased flexibility in the use of
data
 Requires a database management
system (DBMS)
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5. THE DATABASE APPROACH TO
DATA MANAGEMENT
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6. 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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7. DATABASE DESIGN
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CREATING AND MODIFYING A DATABASE
 Typical uses of a data dictionary
 Provide 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.

9. CREATING AND MODIFYING A DATABASE
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10. UPDATING A DATABASE
 Databases are updated by adding, modifying, or deleting
records
 Essential to maintain data accuracy and integrity
 Front-end applications can be used to enter changes
which are then transferred to the database
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11. UPDATING A DATABASE
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12. MANIPULATING DATA AND GENERATING
REPORTS
 Data manipulation language (DML)
 Query by example (QBE)
 Structured Query Language (SQL)
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13. MANIPULATING DATA AND GENERATING
REPORTS
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14. DATABASE BACKUP AND RECOVERY
 Database backup
 Database recovery
 Redundant array of independent
disks (RAID)
 Storage area network (SAN)
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15. 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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16. DATA WAREHOUSES, DATA MARTS,
AND DATA MINING
 Data warehouse
 Data mart
 Data mining
 Business intelligence
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17. DATA WAREHOUSES, DATA MARTS,
AND DATA MINING
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18. TRENDS – DISTRIBUTED DATABASES
 Distributed database
• Also called a virtualized database
 Actual data may be spread across several databases at
different locations, allow more users direct access at
different user sites
 Replicated database
 Database that holds a duplicate set of frequently used
data
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19. TRENDS – DISTRIBUTED DATABASES
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20. 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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21. DATABASE SYSTEMS, THE INTERNET,
AND NETWORKS
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22. VISUAL, AUDIO, UNSTRUCTURED,
AND OTHER DATABASE SYSTEMS
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 Organizations are finding needs to store visual and audio
data.
 Music companies
 Drug companies.
 Law enforcement.
 Unstructured database.

23. VISUAL, AUDIO, UNSTRUCTURED,
AND OTHER DATABASE SYSTEMS
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24. 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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