A database instance (Server) is a set of memory structure and background processes that access a set of database files. The process can be shared by all users. The memory structure that are used to store most queried data from database. This helps up to improve database performance by decreasing the amount of I/O performed against data file.
What is the use of ANALYZE command?
To perform one of these function on an index,table, or
cluster:
- To collect statistics about object used by the optimizer
and store them in the data dictionary.
- To delete statistics about the object ussed by object
from the data dictionary.
- To validate the structure of the object..
- To identify migrated and chained rows off the table
or cluster.
What is default tablespace?
The Tablespace to contain schema objects created without specifying a tablespace name.
What are the system resources that can be controlled through Profile?
The number of concurrent sessions the user can establish the CPU processing time available to the user's session the CPU processing time available to a single call to ORACLE made by a SQL statement the amount of logical I/O available to the user's session the amout of logical I/O available to a single call to ORACLE made by a SQL statement the allowed amount of idle time for the user's session the allowed amount of connect time for the user's session.
What is Tablespace Quota?
The collective amount of disk space available to the objects in a schema on a particular tablespace.
What are the different Levels of Auditing?
Statement Auditing, Privilege Auditing and Object Auditing.
What is Statement Auditing?
Statement auditing is the auditing of the powerful system privileges without regard to specifically named objects.
What are the database administrators utilities avaliable?
SQL * DBA - This allows DBA to monitor and control an ORACLE database. SQL * Loader - It loads data from standard operating system files (Flat files) into ORACLE database tables. Export (EXP) and Import (imp) utilities allow you to move existing data in ORACLE format to and from ORACLE database.
How can you enable automatic archiving?
Shut the database
Backup the database
Modify/Include LOG_ARCHIVE_START_TRUE in init.ora file.
Start up the database.
What are roles? How can we implement roles?
Roles are the easiest way to grant and manage common privileges needed by different groups of database users. Creating roles and assigning provides to roles. Assign each role to group of users. This will simplify the job of assigning privileges to individual users.
What are Roles?
Roles are named groups of related privileges that are granted to users or other roles.
What are the use of Roles?
REDUCED GRANTING OF PRIVILEGES - Rather than explicitly
granting the same set of privileges to many users a database administrator
can
grant the privileges for a group of related users granted
to a role and then grant only the role to each member of the group.
DYNAMIC PRIVILEGE MANAGEMENT - When the privileges of
a group must change, only the privileges of the role need to be modified.
The
security domains of all users granted the group's role
automatically reflect the changes made to the role.
SELECTIVE AVAILABILITY OF PRIVILEGES - The roles granted
to a user can be selectively enable (available for use) or disabled (not
available for use). This allows specific control of a
user's privileges in any given situation.
APPLICATION AWARENESS - A database application can be
designed to automatically enable and disable selective roles when a user
attempts to use the application.
