presentation

Part V: Data Administration

Chapter 13: Data and Database Administration

Chapter 14: Data Warehouse

Chapter 13: Data and Database Administration

Data Administrator

Database Administrator

Modeling and Planning Enterprise Data

Data Security

Backup

Concurrent Access

Data Quality

Data Administrator

Custodian of the organization’s dataDevelops procedures to protect and control data

resourceMaintains corporate-wide data definitions and

standardsFunctional responsibilities: planning, analysis, design,

implementation, maintenance, protectionShould be a respected, senior-level middle managerRequires a high level of managerial and technical skills

Database Administrator

Responsible for physical database design and technical issues

Carries through the standards and procedures established by data administrator

Broad technical backgroundManagerial skills are also critical

Corporate Data Management

Functions:data policies, procedures, and standardsplanningdata conflict resolutioninternal marketingmanaging the data repositoryselection of hardware and softwaremanaging data security, privacy, and integritydata backup and recovery

Modeling Enterprise Data

Enterprise architecture: “that set of descriptive representations that are relevant for describing an enterprise such that it can be produced to management’s requirements and maintained over the period of its useful life.”

The conceptual data model must mesh with …business process modelbusiness network logisticswork flow modelsenterprise master scheduleenterprise business plan

Planning for Databases

What data will be included?What processes will the system perform?What business locations will the system

affect?What work units and people will be affected

by the system?How will the system fit with significant

business effects?

Managing Data Security

Threats to data securityaccidental: human, software, hardware errortheft and fraudloss of privacy or confidentialityloss of data integrityloss of availability

Data security planlimit access (4 methods)conceal datafacilitate recovery

Security: Views

Presents only data to which a user needs access

Always shows current dataMore sophisticated security measures are

normally required

Security: Authorization Rules

Restrict access to dataRestrict actions that may be takenAuthorization tables for subjects (users)Authorization tables for objects (data)

Security: User-Defined Procedures

For example, a series of questions

Security: Encryption

Security: Authentication Schemes

Database Recovery

Backup facilitiesstatic data … dynamic data … incremental backup

Journalizing facilitiestransaction log … before-image … after-image

Checkpoint facilityprovides known state from which recovery can be

done

Recovery manager

Recovery and Restart Procedures

Switch (mirrored database)Restore/Rerun: reprocess transactionsTransaction integrity

commit or abortbackward recovery – rollback – undo transactionsforward recovery -- rollforward – apply

transactions

Concurrent Access

Pessimistic: lockingOptimistic: versioningReading

no concurrency issues

Writingincompatible updatesinaccurate data read by another

Locking Mechanisms

Locking level (granularity)database … table … block/page … record … fieldshared locksexclusive locks

Deadlocksprevention by lock all at starttwo-phase: lock all, then releaseresolution: backout transactions

Versioning

Only one user may make changesOther users restricted from changing, must

restart

Managing Data Quality

Security policy and disaster recoveryPersonnel controlsPhysical access controlsMaintenance controlsData protection and privacy

Chapter 14: Data Warehouse

Data Warehouse Architecture

Data Characteristics

Reconciled Data Layer

Data Transformation

Derived Data Layer

User Interface

Two Types of Processing

Operational processingcaptures, stores, and manipulates data to support daily

operations

Informational processinganalysis of summarized data to support decision

making

Data warehouses consolidate and integrate information from many

different sources and arrange it in a meaningful format for making accurate business decisions

Data Warehouse Architectures

Two-level architecturesource files …

read-only data warehouse

Three-level architecturesource files …

enterprise data warehouse (reconciled data) … data mart (derived data)

Data Characteristics

Status vs. event databalance vs. transaction

Transient vs. periodic datacurrent balance vs. balance history

Reconciled Data Layer

Used to build data warehouseCharacteristics of reconciled data

detailedhistoricalnormalizedcomprehensivequality controlled

Capture Scrub Transform Load

Derived Data Layer

Data that have been selected, formatted, and aggregated

Star schemadimension table: “demographic data”fact table: “associative data” – often summarized

User Interface

Traditional query and reporting toolsOn-line analytical processing (OLAP)

cube slicingdrill-down

Data miningexplanatoryconfirmatoryexploratory

Data visualization