The document discusses the responsibilities of a database administrator (DBA). The DBA formulates and enforces policies regarding database access, security, disaster planning, and archiving. Technically, the DBA is responsible for database design, testing, performance tuning, and maintenance of the database management system. The DBA also evaluates and selects database software, provides training to users, and ensures database security, backups, and system availability.
1. Database Administration
*
ObjectivesDiscuss the need for database administrationExplain
the DBA’s responsibilities in formulating and enforcing
database policies for access privileges, security, disaster
planning, and archivingDiscuss the DBA’s administrative
responsibilities for DBMS evaluation and selection, DBMS
maintenance, data dictionary management, and trainingDiscuss
the DBA’s technical responsibilities for database design,
testing, and performance tuning
*
*
Introduction
FIGURE 8-1: DBA responsibilities
*
2. *
Database Policy Formulation and EnforcementDBAFormulates
database policiesCommunicates policies to usersEnforces
policiesPoliciesAccess privilegesSecurityDisaster
planningArchiving
*
*
Access PrivilegesDBADetermines access privileges for all
usersEnters appropriate authorization rules in DBMSSQL
GRANT statementAccess privilege policyDocumented by
DBAApproved by top-level managementCommunicated by DBA
to all users
*
*
Access Privileges (continued)
FIGURE 8-2: Permitted and denied access privileges for Sam
*
3. *
Access Privileges (continued)
FIGURE 8-4: Permitted and denied access privileges for Valerie
*
*
SecurityPrevention of unauthorized access, intentional or
accidental, to databaseDBACreates security policies and
proceduresObtains management approval of policies and
proceduresDistributes policies and procedures to authorized
users
*
*
Security (continued)DBMS’s security
featuresEncryptionAuthenticationAuthorizationsViewsAdditiona
l security programs may be created or purchasedMonitoring of
database usage to detect security violations
*
*
4. Security (continued)
FIGURE 8-5: Attempted security violation by Brady, who’s not
an authorized user
*
*
Security (continued)
FIGURE 8-6: Attempted security violation by Paige, who’s
authorized to access some customer data but is not authorized to
access customer balances
*
*
Disaster PlanningDamage from physical
incidentsSoftware/hardware/electricalNatural disastersDisaster
recovery plan: ongoing and emergency actions and procedures
to ensure data availability if a disaster occursHard drive
failuresRedundant array of inexpensive/independent drives
(RAID): database updates replicated to multiple hard drives
*
5. *
Disaster Planning (continued)Electrical power
lossUninterruptible power supply (UPS): power source and
power generatorDuplicate backup systemsHot site: completely
equipped with duplicate hardware, software, and dataCan switch
to hot site in minutes or hoursWarm site: duplicate hardware
and software but not dataTakes longer to start processing
*
*
ArchivingGovernmental laws and regulations, for
example:Sarbannes-Oxley ActPatriot ActHIPAAAuditing and
financial requirementsData archive or archive: place where
record of certain corporate data is keptStored on mass storage
devicesCopies of archives and database backups must be stored
off-site
*
*
Archiving (continued)
FIGURE 8-7: Movement of order 21617 from the database to
the archive
*
6. *
Other Database Administration FunctionsDBMS evaluation and
selectionDBMS maintenanceData dictionary
managementTraining
*
*
DBMS Evaluation and SelectionData definitionData
restructuringNonprocedural languagesProcedural languagesData
dictionaryConcurrent updateShared lock
*
*
DBMS Evaluation and Selection (continued)Backup and
recoverySecurityIntegrityReplication and distributed
databasesLimitationsLocal area network (LAN)Documentation
and trainingContext-sensitive help
*
7. *
DBMS Evaluation and Selection (continued)Vendor
supportPerformancePortabilityIntranetCostFuture plansOther
considerations
*
*
DBMS MaintenanceInstallation of DBMSConfiguration
changesUpgrades for new releasesProblem resolutionSpecial
one-time processing needs
*
*
Data Dictionary ManagementData dictionary is like database
catalog, but with wider range of informationEstablishes naming
conventions for tables, fields, indexes, etc.Creates data
definitions for tablesCreates data integrity rules and user
viewsUpdates data dictionaryCreates and distributes reports
from data dictionary
*
8. *
TrainingTraining in using DBMS and accessing
databaseTraining of technical staff responsible for developing
and maintaining database applicationsIf training is provided by
vendor of DBMS, DBA handles scheduling of training
*
*
Technical FunctionsDatabase designTestingPerformance tuning
*
*
Database DesignEstablishes sound methodology for database
designDoes physical-level designCreates documentation
standardsReviews changes to requirements and manages
modifications to database
*
*
9. TestingProduction system or live system: hardware, software,
and database for users DBA grants access to production system
only to authorized users, except for:Troubleshooting a
problemAddition of new or modified programsTest system or
sandbox: used by programmers to develop new programs and
modify existing programs
*
*
Testing (continued)
FIGURE 8-9: DBA controls the interaction between the test and
production systems
*
*
Performance TuningDBA attempts to get best performance
within funding constraintsCreating and deleting
indexesSplitting tablesChanging table designDenormalizing
converts a table in third normal form to a table not in third
normal formImproved performance
*
10. *
Performance Tuning (continued)
FIGURE 8-10: Customer table for Premiere Products
*
*
Performance Tuning (continued)
FIGURE 8-11: Result of splitting the Customer table into two
tables
*
*
Performance Tuning (continued)
FIGURE 8-11: Result of splitting the Customer table into two
tables (continued)
*
*
11. Performance Tuning (continued)
FIGURE 8-12: Including part descriptions in the OrderLine
table, which creates a first normal form table
*
*
SummaryDatabase administrator (DBA) is responsible for
supervising the database and use of the DBMSDBA formulates
and enforces policies about which users can access database,
portions they may access, and the manner in which they can
access itDBA formulates and enforces policies about security by
using DBMS’s security features, special security programs, and
monitoring database usageDBA creates and implements backup
and recovery procedures as part of a disaster recovery plan
*
*
Summary (continued)DBA formulates and enforces policies that
govern management of an archive for dataDBA leads evaluation
and selection of new DBMSDBA installs and maintains
DBMSDBA maintains data dictionary, establishes naming
conventions for its content, and provides information from it to
othersDBA provides database and DBMS training and
coordinates and schedules training by outside vendors
*
