3-Information System Architecture and Software Flashcards
Function performed by OS
•Access to peripheral devices • Storage management• process management • Resource allocation• Communication • Security.
Cluster mode
active-passive mode : One computer is active, and the remaining stay passive.
active-active : All computers are active
what is failover
When in active-passive mode, a passive computer takes over when a active computer fails.
Directory
A structure that is used to store files. A file system contains one or more directories.
A file
A sequence of zero or more characters that are stored as a whole
What control are contained in DBMS
Authentication and access control - permitting control over which users may access what data.
Data Definition Language (DDL)
Used to define the structure of the data contained in a database
Type of DBMSs
Relational object, hierarchical
Primary Key
field in the table whose values are unique in the table
Foreign Key
A field in a record in one that can reference a primary key in another table.
Referential Integrity
In relational database, a row cannot be deleted from a table if there are records in other tables whose foreign keys reference the row to be deleted.
Relational Database Security
- Access Controls -limit read and write access
- encryption - to encrypt some field of the data
- audit logging- to permit an admin to view some or all activities that take place in a database
Utility software
broad class of programs that support the development or use networks, information systems, OS and applications.
Type of networks
- Personal area network (PAN) : Used by a single individual.
- Local area network (LAN) : Connect computers and devices together in a small building or residence.
- Campus Area Network (CAN) : Interconnection of LANs of an organization that has buildings in close proximity.
- Metropolitan Area Network (MAN) : A network that spans a city or regional area.
- Wide Area Network (WAN) ;Network whose size ranges from regional to international.
Network based services
Protocols and utilities that facilitate system-and network resource utilization.