CIS 233 Final
Distributed database management system
A DBMS capable of supporting and manipulating distributed databases
After a DBMS has been selected, what is the DBAs role in the DBMS maintenance
installation of DBMS Problem resolution configuration chages
Concurrent update
occurs when multiple users make updates to the same database at the same time
data dictionary
like a database catalog with a wider range of information
3 characteristics of distributed database system
location transparency replication transparency fragmentation transparency
Journaling
maintaining a log of all updates
Data replication
manage multiple copies of same data in multiple locations
deadlock
occurs in a concurrent update situation when the first user is waiting for data that has been locked by the 2nd user and vice versa
database archive
retaining data for future reference, following laws or regulations
Data syncnronization
DBMS exchanges all updated data between master database and replica
locking
denies access by others users to data while the DBMS processes one users updates to the database. prevents lost updates
XML
a text based markup language designed for the exchange of data on the web
List 5 categories that we find on a DBMS evaluation and selection checklist
data dictionary limitations vendor support backup and recovery concurrent update
database backup
for data recovery data can quickly be recovered when performed periodically
distributed database management system (DDBMS)
a single logical database that is physically divided among computers at several sites on a network
Data warehouse
a subject oriented time-variant, nonvolatile collection of data in support of managements decision making process
Two-Phase locking
an approach for handling locks to prevent lost updates. the first phase locks rows and releases none while in the second phase the DBMS releases the locks
