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Data Administration and
Database Administration
University of California, Berkeley
School of Information Management and
Systems
SIMS 257: Database Management
10/17/2000
Database Management -- R. Larson
Mid-Term Assignment #5
• See WWW site:
– http://sims.berkeley.edu/courses/is257/f00/index.html
• Report on personal database including:
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10/17/2000
Database description
Data Dictionary
Relationships Diagram
Sample queries and results
Sample forms
Sample reports
Database Management -- R. Larson
Review
• Web enabled database systems
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Database Management -- R. Larson
Why Use a Database System?
• Database systems have concentrated on providing
solutions for many issues in scaling up Web
applications
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Performance
Scalability
Maintenance
Data Integrity
Transaction support
• While systems differ in their support, most offer
some support for all of these.
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Database Management -- R. Larson
Dynamic Web Applications 2
Web
Server
Internet
Files
CGI
DBMS
Server
database
database
database
10/17/2000
Clients
Database Management -- R. Larson
Server Interfaces
SQL
HTML
DHTML
Web Server
JavaScript
Native
DB
Interfaces
Database
Web DB
CGI
App ODBC
Web Server
API’s
ColdFusion
Native DB
interfaces
JDBC
PhP Perl
Web Application
Server
Adapted from
John P Ashenfelter,
Choosing a Database for Your Web Site
10/17/2000
Java
ASP
Database Management -- R. Larson
What Database systems are
available?
• Choices depend on:
– Size (current and projected) of the application
– Hardware and OS Platforms to be used in the
application
– Features required
• E.g.: SQL? Upgrade path? Full-text indexing? Attribute size
limitations? Locking protocols? Direct Web Server access?
Security?
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Staff support for DBA, etc.
Programming support (or lack thereof)
Cost/complexity of administration
Budget
Database Management -- R. Larson
Desktop Database Systems
System (producer)Platform
SQL
ODBC
Scaling
Access (Microsoft)
FoxPro (Microsoft)
FileMaker (FileMaker)
Excel (Microsoft)
Files (owner)
Yes
Yes
No
No
No
Yes
Yes
No
Yes
No
SQL Server
~$200
SQL Server
~$200
FileMaker Server ~$200
Convert to Access~$200
Import into DB ?
Windows
Windows,
Windows,
Windows,
Windows,
Mac
Mac
Mac
Mac
Price
• Individuals or very small enterprises can create
DBMS-enabled Web applications relatively
inexpensively
• Some systems will require an application server
(such as ColdFusion) to provide the access path
between the Web server and the DBMS
10/17/2000
Database Management -- R. Larson
Enterprise Database Systems
System
Platform
SQL ODBC JDBC Web?
SQL-Server (Microsoft)
Oracle Internet Platform
Informix Internet Foundation.2000
Sybase Adaptive Server
DB2 (IBM)
WIndowsNT -2000
Unix, Linux, NT
Unix, Linux, NT
Unix, Linux, NT
IBM,Unix, Linux, NT
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
?
Yes
Yes
Yes
Yes
Yes (IIS)
Yes
Yes
Yes
Yes?
• Enterprise servers are powerful and
available in many different configurations
• They also tend to be VERY expensive
• Pricing is usually based on users, or CPU’s
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Database Management -- R. Larson
Free Database Servers
System
Platform
SQL ODBC JDBC Web?
mSQL
Unix, Linux
Yes
MySQL
Unix, Linux, NT Yes
PostgreSQL Unix, Linux, NT Yes
Yes
Yes
Yes
No(?)
No(?)
Yes
No?
No?
No?
• System is free, but there is also no help line.
• Include many of the features of Enterprise systems, but
tend to be lighter weight
• Versions may vary in support for different systems
• Open Source -- So programmers can add features
10/17/2000
Database Management -- R. Larson
Embedded Database Servers
System
Platform
SQL ODBCJDBC Web?
Sleepycat DB Unix, Linux, Win No
Solid
Unix, Linux, Win Yes
No
Yes
Java API No?
Yes
Yes
• May require programming experience to
install
• Tend to be fast and economical in space
requirements
10/17/2000
Database Management -- R. Larson
Database Security
• Different systems vary in security support:
– Views or restricted subschemas
– Authorization rules to identify users and the actions
they can perform
– User-defined procedures (and rule systems) to define
additional constraints or limitations in using the
database
– Encryption to encode sensitive data
– Authentication schemes to positively identify a person
attempting to gain access to the database
10/17/2000
Database Management -- R. Larson
Web Application Server Software
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ColdFusion
PHP
ASP
All of the are server-side scripting
languages that embed code in HTML pages
10/17/2000
Database Management -- R. Larson
ColdFusion
• Started as CGI
– Drawback, as noted above, is that the entire
system is run for each cgi invocation
• Split into cooperating components
– NT service -- runs constantly
– Server modules for 4 main Web Server API
(glue that binds web server to ColdFusion
service) {Apache, ISAPI, NSAPI, WSAPI}
– Special CGI scripts for other servers
10/17/2000
Database Management -- R. Larson
What ColdFusion is Good for
• Putting up databases onto the Web
• Handling dynamic databases (Frequent
updates, etc)
• Making databases searchable and
updateable by users.
10/17/2000
Database Management -- R. Larson
Requirements
• Unix or NT systems
• Install as SuperUser
• Databases must be defined via “data source
names (DSNs) by administrator
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Database Management -- R. Larson
Requirements and Set Up
• Field names should be devoid of spaces. Use the
underscore character, like new_items instead of
"new items."
• Use key fields. Greatly reduces search time.
• Check permissions on the individual tables in your
database and make sure that they have read-access
for the username your Web server uses to log in.
• If your fields include large blocks of text, you'll
want to include basic HTML coding within the text
itself, including boldface, italics, and paragraph
markers.
10/17/2000
Database Management -- R. Larson
Templates cont.
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<HEAD>
<TITLE>Contents of My Shopping Cart</TITLE>
</HEAD>
<BODY>
<H1>Contents of My Shopping Cart</H1>
<CFOUTPUT QUERY= ”cart">
<B>#Item#</B> <BR>
#Date_of_item# <BR>
$#Price# <P>
</CFOUTPUT>
</BODY>
</HTML>
10/17/2000
Database Management -- R. Larson
CFML ColdFusion Markup
Language
• Read data from and update data to databases and
tables
• Create dynamic data-driven pages
• Perform conditional processing
• Populate forms with live data
• Process form submissions
• Generate and retrieve email messages
• Perform HTTP and FTP function
• Perform credit card verification and authorization
• Read and write client-side cookies
10/17/2000
Database Management -- R. Larson
PHP
• PHP is an Open Source Software project with
many programmers working on the code.
– Commonly paired with MySQL, another OSS project
– Free
– Both Windows and Unix support
• Estimated that more than 250,000 web sites use
PHP as an Apache Module.
10/17/2000
Database Management -- R. Larson
PHP Syntax
• Similar to ASP
<HTML><BODY>
<?php
$myvar = “Hello World”;
echo $myvar ;
?>
</BODY></HTML>
• Includes most programming structures (Loops,
functions, Arrays, etc.)
• Loads HTML form variables so that they are
addressable by name
10/17/2000
Database Management -- R. Larson
Combined with MySQL
• DBMS interface appears as a set of
functions:
<HTML><BODY>
<?php
$db = mysql_connect(“localhost”, “root”);
mysql_select_db(“mydb”,$db);
$result = mysql_query(“SELECT * FROM employees”, $db);
Printf(“First Name: %s <br>\n”, mysql_result($result, 0 “first”);
Printf(“Last Name: %s <br>\n”, mysql_result($result, 0 “last”);
?></BODY></HTML>
10/17/2000
Database Management -- R. Larson
ASP – Active Server Pages
• Another server-side scripting language
• From Microsoft using Visual Basic as the
Language model (VBScript), though
Javascript (actually MS Jscript) is also
supported
• Works with Microsoft IIS and gives access
to ODBC databases
10/17/2000
Database Management -- R. Larson
ASP Syntax
<%
SQL="SELECT last, first FROM employees
ORDER BY last"
set conn = server.createobject("ADODB.Connection")
conn.open “employee"
set people=conn.execute(SQL)
%>
<% do while not people.eof
set resultline=people(0) & “, “ & people(1) & “<BR>”
Response.Write(resultline)
people.movenext
loop%>
<% people.close %>
10/17/2000
Database Management -- R. Larson
Conclusions
• Database technology is a required
component for large-scale dynamic Web
sites, especially E-Commerce sites
• Web databases cover most of the needs of
dynamic sites (except for text search)
• Many solutions and systems are available
for web-enabled databases
10/17/2000
Database Management -- R. Larson
Today
• Data Administration
• Database Administration
10/17/2000
Database Management -- R. Larson
Terms and Concepts
• Data Administration
– Responsibility for the overall management of
data resources within an organization
• Database Administration
– Responsibility for physical database design and
technical issues in database management
• Data Steward
– Responsibility for some subset of the
organization’s data, and all of the interactions
(applications, user access, etc.) for that data
10/17/2000
Database Management -- R. Larson
Terms and Concepts
• DA
– Data adminstrator - person responsible for the
Data Administration function in an organization
– Sometimes may be the CIO -- Chief
Information Officer
• DBA
– Database Administrator - person responsible for
the Database Administration Function
10/17/2000
Database Management -- R. Larson
Database System Life Cycle
Database
Planning
Database
Analysis
Growth &
Change
Operation &
Maintenance
Database
Design
Database
Implementation
10/17/2000
Database Management -- R. Larson
Note: this is a different version of this
life cycle than discussed previously
Database Planning
• Development of a strategic plan for
database development that supports the
overall organization’s business plan.
• DA supports top management in
development of this plan.
• The result of this stage is an enterprise data
model.
10/17/2000
Database Management -- R. Larson
Database Planning:
DA & DBA functions
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Develop corporate database strategy (DA)
Develop enterprise model (DA)
Develop cost/benefit models (DA)
Design database environment (DA)
Develop data administration plan (DA)
10/17/2000
Database Management -- R. Larson
Database Analysis
• This is the process (discussed previously) of
identifying data entities currently used by the
organization, precisely defining those entities and
their relationships, and documenting the results in
a form that can support the follow-on design
phase.
• Must also identify new data elements or changes
to data elements that will be required in the future.
• The result of this phase is the Conceptual Data
Model -- usually represented as an ER diagram.
10/17/2000
Database Management -- R. Larson
Database Analysis:
DA & DBA functions
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Define and model data requirements (DA)
Define and model business rules (DA)
Define operational requirements (DA)
Maintain corporate Data Dictionary (DA)
10/17/2000
Database Management -- R. Larson
Database Design
• Purpose of the design phase is the
development of the logical database design
that will serve the needs of the organization
and the physical design implementing the
logical design.
• In relational systems the outcome is
normalized relations, and the data definition
for a particular database systems (including
indexes, etc.)
10/17/2000
Database Management -- R. Larson
Design 2: Physical Creation
• Development of the Physical Model of the
Database
– data formats and types
– determination of indexes, etc.
• Load a prototype database and test
• Determine and implement security, privacy
and access controls
• Determine and implement integrity
constraints
10/17/2000
Database Management -- R. Larson
Database Design:
DA &DBA functions
• Perform logical database design (DA)
• Design external models (subschemas)
(DBA)
• Design internal model (Physical design)
(DBA)
• Design integrity controls (DBA)
10/17/2000
Database Management -- R. Larson
Database Implementation
• Database design gives you an empty
database
• Load data into the database structure
• Convert existing data sets and applications
to use the new database
– May need programs, conversion utilities to
convert old data to new formats.
• Outcome is the actual database with its data
10/17/2000
Database Management -- R. Larson
Database Implementation
DA & DBA functions
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Specify database access policies (DA & DBA)
Establish Security controls (DBA)
Supervise Database loading (DBA)
Specify test procedures (DBA)
Develop application programming standards
(DBA)
• Establish procedures for backup and recovery
(DBA)
• Conduct User training (DA & DBA)
10/17/2000
Database Management -- R. Larson
Operation and Maintenance 1:
Operations
• Users are responsible for updating the
database, DA and DBA are responsible for
developing procedures that ensure the
integrity and security of the database during
the update process.
• Specific responsibility for data collection,
editing and verification must be assigned
• Quality assurance must be practiced to
protect and audit the database quality.
10/17/2000
Database Management -- R. Larson
Operation and Maintenance 2:
Maintenance
• The ongoing process of updating the database to
keep it current
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adding new records
deleting obsolete records
changing data values in particular records
modifying relation structures (e.g. adding new fields)
• Privacy, security, access control must be in place.
• Recovery and Backup procedures must be
established and used
10/17/2000
Database Management -- R. Larson
Operation and Maintenance:
DA & DBA functions
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Monitor database performance (DBA)
Tune and reorganize databases (DBA)
Enforce standards and procedures (DBA)
Support users (DA & DBA)
10/17/2000
Database Management -- R. Larson
Growth & Change
• Change is a way of life
– Applications, data requirements, reports, etc.
will all change as new needs and requirements
are found
– The Database and applications and will need to
be modified to meet the needs of changes to the
organization and the environment.
– Database performance should be monitored to
maintain a high level of system performance.
10/17/2000
Database Management -- R. Larson
Growth & Change:
DA & DBA functions
• Implement change control procedures (DA
& DBA)
• Plan for growth and change (DA & DBA)
• Evaluate new technology (DA & DBA)
10/17/2000
Database Management -- R. Larson
Issues/functions in Database
Administration
• Planning and Design (we have already
looked at theses processes in detail)
• Data Integrity
• Backup and Recovery
• Security Management
10/17/2000
Database Management -- R. Larson
Data Integrity
• Intrarecord integrity (enforcing constraints
on contents of fields, etc.)
• Referential Integrity (enforcing the validity
of references between records in the
database)
• Concurrency control (ensuring the validity
of database updates in a shared multiuser
environment).
10/17/2000
Database Management -- R. Larson
No Concurrency Control:
Lost updates
John
• Read account balance
(balance = $1000)
• Withdraw $200 (balance =
$800)
• Write account balance
(balance = $800)
10/17/2000
Marsha
• Read account balance
(balance = $1000)
• Withdraw $300 (balance =
$700)
• Write account balance
(balance = $700)
Database Management -- R. Larson
ERROR!
Concurrency Control:
Locking
• Locking levels
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Database
Table
Block or page
Record
Field
• Types
– Shared (S locks)
– Exclusive (X locks)
10/17/2000
Database Management -- R. Larson
Concurrency Control: Updates
with X locking
John
• Lock account balance
• Read account balance
(balance = $1000)
• Withdraw $200 (balance =
$800)
• Write account balance
(balance = $800)
• Unlock account balance
10/17/2000
Marsha
• Read account balance
(DENIED)
• Lock account balance
• Read account balance
(balance = $800)
• etc...
Database Management -- R. Larson
Concurrency Control:
Deadlocks
John
• Place S lock
• Read account balance
(balance = $1000)
Marsha
• Place S lock
• Read account balance
(balance = $1000)
• Request X lock (denied)
• wait ...
• Request X lock (denied)
• wait...
10/17/2000
Database Management -- R. Larson
Deadlock!
Concurrency Control
• Avoiding deadlocks by maintaining tables
of potential deadlocks and “backing out”
one side of a conflicting transaction.
10/17/2000
Database Management -- R. Larson
Database Security
• Views or restricted subschemas
• Authorization rules to identify users and the
actions they can perform
• User-defined procedures (and rule systems) to
define additional constraints or limitations in using
the database
• Encryption to encode sensitive data
• Authentication schemes to positively identify a
person attempting to gain access to the database
10/17/2000
Database Management -- R. Larson
Views
• A subset of the database presented to some
set of users.
– SQL: CREATE VIEW viewname AS SELECT
field1, field2, field3,…, FROM table1, table2
WHERE <where clause>;
– Note: “queries” in Access function as views.
10/17/2000
Database Management -- R. Larson
Authorization Rules
• Most current DBMS permit the DBA to
define “access permissions” on a table by
table basis (at least) using the GRANT and
REVOKE SQL commands.
• Some systems permit finer grained
authorization (most use GRANT and
REVOKE on variant views.
10/17/2000
Database Management -- R. Larson
Database Backup and Recovery
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Backup
Journaling (audit trail)
Checkpoint facility
Recovery manager
10/17/2000
Database Management -- R. Larson