10/25/2001Database Management -- R. Larson Data Administration and Database Administration University of California, Berkeley School of Information Management

10/25/2001 Database Management -- R. Larson

Data Administration and Database Administration

University of California, Berkeley

School of Information Management and Systems

SIMS 257: Database Management


Mid-Term Assignment #5

• See WWW site:– http://sims.berkeley.edu/courses/is257/f01/index.html

• Report on personal database including:– Database description– Data Dictionary– Relationships Diagram– Sample queries and results– Sample forms– Sample reports

http://sims.berkeley.edu/courses/is257/f01/index.html


Today

• Data Administration

• Database Administration


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


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


Database System Life Cycle

Operation &Maintenance

DatabaseImplementation

DatabaseDesign

Growth &Change

DatabaseAnalysis

DatabasePlanning

Note: this is a different version of thislife 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.


Database Planning:DA & DBA functions

• Develop corporate database strategy (DA)

• Develop enterprise model (DA)

• Develop cost/benefit models (DA)

• Design database environment (DA)

• Develop data administration plan (DA)


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.


Database Analysis:DA & DBA functions

• Define and model data requirements (DA)

• Define and model business rules (DA)

• Define operational requirements (DA)

• Maintain corporate Data Dictionary (DA)


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.)


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


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)


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


Database ImplementationDA & DBA functions

• 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)


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.


Operation and Maintenance 2:Maintenance

• The ongoing process of updating the database to keep it current – 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


Operation and Maintenance:DA & DBA functions

• Monitor database performance (DBA)

• Tune and reorganize databases (DBA)

• Enforce standards and procedures (DBA)

• Support users (DA & DBA)


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.


Growth & Change:DA & DBA functions

• Implement change control procedures (DA & DBA)

• Plan for growth and change (DA & DBA)

• Evaluate new technology (DA & DBA)


Issues/functions in Database Administration

• Planning and Design (we have already looked at theses processes in detail)

• Data Integrity

• Backup and Recovery

• Security Management


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).


No Concurrency Control:Lost updates

• Read account balance (balance = $1000)

• Withdraw $200 (balance = $800)

• Write account balance (balance = $800)




John Marsha

ERROR!


Concurrency Control:Locking

• Locking levels– Database

– Table

– Block or page

– Record

– Field

• Types– Shared (S locks)

– Exclusive (X locks)


Concurrency Control: Updates with X locking

• Lock account balance




• Unlock account balance

• Read account balance (DENIED)

• Lock account balance


• etc...

John Marsha


Concurrency Control:Deadlocks

• Place S lock


• Request X lock (denied)

• wait ...

• Place S lock


• Request X lock (denied)

• wait...

John Marsha

Deadlock!


Concurrency Control

• Avoiding deadlocks by maintaining tables of potential deadlocks and “backing out” one side of a conflicting transaction.


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


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.


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.


Database Backup and Recovery

• Backup

• Journaling (audit trail)

• Checkpoint facility

• Recovery manager


Disaster Recovery Planning

Testing andTraining

ProceduresDevelopment

Budget &Implement

PlanMaintenance

RecoveryStrategies

RiskAnalysis

From Toigo “Disaster Recovery Planning”


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


Issues/functions in Database Administration

• Planning and Design (we have already looked at theses processes in detail)

• Data Integrity

• Backup and Recovery

• Security Management


Today

• Additional issues– Handling special data considerations– Database/Data Dictionary– Database Building in SQL (maybe)

Documents

10/25/2001Database Management -- R. Larson Data Administration and Database Administration University of California, Berkeley School of Information Management