Transcript DBMS - jaw group

What is DBMS?
DBMS: computer software designed to manage databases based on
a variety of data models.
DBMS functions
Stores data
Updates data
Retrieves data
Summary: DBMS is designed to store and manage databases.
Elements of DBMS
DBMS is composed of
1- Modeling language
(allows database to communicate)
2-Datastructure
(allows DBMS to interact without
causing damage to data integrity)
3-Database query language
(maintains security of DB)
4-Transaction mechanism
(data integrity)
Hierarchical
Network
Relational
Object examples
Fields
Records
Files
Objects
Login data
Assignment of access rights & privileges
Definition of criterias employed to add data in the system
Allows multiple access to database
Prevents manipulation of records by multiple useras at
the same time
Description of DBMS components
1. Modeling language: defines the schema of each
database.
2. Datastructure: deals with data stored on a
permanent data storage device.
3. Data query language: to allow users to
interrogate the database.
4. Transaction mechanism: ensures data integrity
by not allowing more than one user to update the
same record at the same time.
DBMS vs. Other technologies
DBMS vs. Files:
• Protects data from inconsistency due to multiple
concurrent users.
• Security & access control while sharing data and
processing resources.
• Application allows large data sets between main memory
& secondary storage.
• Allows logical & physical view:
« User’s view »
Data that is meaningful to user
efficient use of storage
& processing ressources
How DBMS works?
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Source: wisdom.usc.edu/stf/research_CM.htm, 2004.
DBMS mid-range vs. mainframe
• Mid-range: DBMS is convenient & marketed in many
forms.
• Mainframe: RDBMS (Relational DBMS) suggested to
take care of large amounts of data.
RDBMS enables relationships between data by a tabular
structure.
Benefits of DBMS
• Uniform data administration:
Reduces complexity of information systems & strategic use of data.
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Data-independance:
Access to data by multiple users at the same time, logical & physical independance.
• Data security & integrity:
Log-in services records access occurrences & changes.
• Reduced application development & maintenace costs:
decreases inconsistency & allows interleaving actions.
• Increases availability of data & its access:
DBMS ensures automicity
• Recovery from crashes:
log entries
Is DBMS revolutionary?
• DMBS: oldest component associated with
computer.
• DBMS marketed in many forms since its
existence: new software programs to meet
requirements of next generation of computing
(for example: RDBMS).
Major players of database
• Oracle, IBM and Microsoft are top 3 vendors, followed by Teradata
and Sybase.
2007 DBMS Market Share*
Sybase
(Sybase IQ)
3%
Vendor (database)
Other
10%
Teradata
3%
Oracle
45%
Microsoft
(SQL Server)
18%
IBM
(DB2, Informix)
21%
Market
Share
Oracle
44.1%
IBM (DB2, Informix)
21.3%
Microsoft (SQL
Server)
18.3%
Teradata
3.4%
Sybase (Sybase IQ)
3.4%
Other
9.5%
Total
100.0
%
Major players of mid-market
database
• Mid-market database:
– Mid-market is defined as businesses ranging from 50 to 1,000 employees *
– Forecasted to be the main growth segment in the IT market for the next few
years ; called 60 billion dollar software battle by the BBC *
• Mid-market Top 5 :*
(based on installed base (1 million or more))
– Oracle's Standard Edition 1
– IBM's DB2 Express
– Microsoft's SQL Server
– MySQL-5 (open-source)
– Firebird (open-source)
*
Source: Selecting a mid-market database, OS News (http://www.nmcx.com/), 2005
Major Players of embedded database
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Embedded database
– Defined as DBMS sold and used as components of a larger software or hardware product
– Offers great growth potential in its various more specialized forms
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Oracle has a leadership in embedded database market
2006 Embedded DBMS Market Share*
Vendor
Oracle
23%
Other
31%
InterSystems
Corp.
10%
*
Sybase
10%
Source: 2007, IDC
IBM
12%
Progress
Software Corp.
14%
Market
Share
Oracle
23.2%
Progress Software Corp.
14.1%
IBM
11.8%
Sybase
10.3%
InterSystems Corp.
10.2%
Other
30.4%
Total
100.0%
Examples of DBMS softwares
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is a program that lets one or more computer users create and access data
in a database
The most typical DBMS is a relational database management system
(RDBMS).
A standard user and program interface is the Structured Query Language
(SQL).
A newer kind of DBMS is the object-oriented database management
system (ODBMS).
A DBMS is usually an inherent part of a database product.
On PCs, Microsoft Access is a popular example of a single- or small-group
user DBMS.
Microsoft's SQL Server is an example of a DBMS that serves database
requests from multiple (client) users.
Other popular DBMSs (these are all RDBMSs, by the way) are IBM's
DB2, Oracle's line of database management products, and Sybase's
products.
Some of the players
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Oracle
DB2
Sybase Adaptive Server Enterprise
Datawasp
FileMaker
Firebird
IBM
Informix
Microsoft Access
Microsoft SQL Server
Microsoft Visual FoxPro
MySQL
Trends
• Business Intelligence (BI): is about the
extraction of information from data.
• Spatial data: main database engines now all have
spatial data types. Spatial data is useful in its own
right, but combine it with Google Earth and/or
Virtual Earth and a quick mashup can give you a very
powerful application for a few lines of code. People
will make far, far more use of spatial data in the
coming year.
Costs and Web Softwares
• Examples of Web Databases for C.R.M.:
• Netsuite.com
• Salesforce.com
salesforce.com
Something New on DBMS
• Security issues:
• Lately, database security issues have been flooding the media
– Slammer worm (computer worm)
– Criminals accessing over 8 million credit card numbers
– Illegally selling personal information stored in the database
• Database security is not just technical problems
– Corporate level: e.g. Who performs security audits on the corporation as a
whole?
– Section level: e.g. How does an organization ensures all system administrators
are applying the latest patches?
– Tech level
• Database connections
• Server Security
• Table access control
• Restricting database access
References
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« Database Management Systems », 1998, Gerald V. Post, Irwin/McGraw-Hill,Bk Edition.
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« Database Management Systems », 1997, Raghu Ramaknishnan, McGraw-Hill Companies.
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« Database Systems Design, Implementation and Management », 1999, Peter Rob, Carlos
Coronel, Cours Technology Ptr, 4th edition.
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In Database Market, Oracle Gets Bigger
(http://www.informationweek.com/shared/printableArticle.jhtml?articleID=207402230), Others Hang
On, InformationWeek, Apr 25, 2008
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Oracle grows lead in database market (http://www.arabianbusiness.com/517936-oracle-growslead-in-database-market), ArabianBusiness.com, Apr 30, 2008
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Selecting a mid-market database (http://www.osnews.com/story/10498), OSNews, May 3, 2005
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Worldwide Embedded DBMS 2007 - 2011 Forecast and 2006 Vendor Shares (Excerpt from IDC #
209653), IDC, 2007
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Database Security (http://www.governmentsecurity.org/articles/DatabaseSecurityCommonsensePrinciples.php), GovernmentSecurity.org