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1.
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What is user Account in Oracle database? |
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A user account is not a physical structure in Database
but it is having important relationship to the objects
in the database and will be having certain privileges
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2.
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How will you enforce security using stored procedures? |
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Don't grant user access directly to tables within the
application.
Instead grant the ability to access the procedures that
access the tables.
When procedure executed it will execute the privilege of
procedures owner. Users cannot access tables except via
the procedure.
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3.
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What are the dictionary tables used to monitor a
database spaces? |
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DBA_FREE_SPACE
DBA_SEGMENTS
DBA_DATA_FILES.
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4.
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What are the responsibilities of a Database
Administrator? |
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• Installing and upgrading the Oracle Server and
application tools.
• Allocating system storage and planning future storage
requirements for the database system.
• Managing primary database structures (tablespaces)
• Managing primary objects (table,views,indexes)
• Enrolling users and maintaining system security.
• Ensuring compliance with Oralce license agreement
• Controlling and monitoring user access to the
database.
• Monitoring and optimising the performance of the
database.
• Planning for backup and recovery of database
information.
• Maintain archived data on tape
• Backing up and restoring the database.
• Contacting Oracle Corporation for technical support.
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5.
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What are the roles and user accounts created
automatically with the database? |
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DBA - role Contains all database system privileges.
SYS user account - The DBA role will be assigned to this
account. All of the basetables and views for the
database's dictionary are store in this schema and are
manipulated only by ORACLE.
SYSTEM user account - It has all the system privileges
for the database and additional tables and views that
display administrative information and internal tables
and views used by oracle tools are created using this
username.
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6.
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What are the database administrator’s utilities
avaliable? |
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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.
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7.
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What are the minimum parameters should exist in the
parameter file (init.ora)? |
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DB NAME - Must set to a text string of no more than 8
characters and it will be stored inside the datafiles,
redo log files and control files and control file while
database creation.
DB_DOMAIN - It is string that specifies the network
domain where the database is created. The global
database name is identified by setting these parameters
(DB_NAME & DB_DOMAIN)
CONTORL FILES - List of control filenames of the
database. If name is not mentioned then default name
will be used.
DB_BLOCK_BUFFERS - To determine the no of buffers in the
buffer cache in SGA.
PROCESSES - To determine number of operating system
processes that can be connected to ORACLE concurrently.
The value should be 5 (background process) and
additional 1 for each user.
ROLLBACK_SEGMENTS - List of rollback segments an ORACLE
instance acquires at database startup.
Also optionally LICENSE_MAX_SESSIONS,
LICENSE_SESSION_WARNING and LICENSE_MAX_USERS.
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8.
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What is a trace file and how is it created? |
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Each server and background process can write an
associated trace file. When an internal error is
detected by a process or user process, it dumps
information about the error to its trace. This can be
used for tuning the database.
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9.
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What are roles? How can we implement roles? |
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Roles are the easiest way to grant and manage common
privileges needed by different groups of database users.
Creating roles and assigning provies to roles.
Assign each role to group of users. This will simplify
the job of assigning privileges to individual users.
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10. |
What are the steps to switch a database's archiving mode
between NO ARCHIVELOG and ARCHIVELOG mode? |
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1. Shutdown the database instance.
2. Backup the databse
3. Perform any operating system specific steps
(optional)
4. Start up a new instance and mount but do not open the
databse.
5. Switch the databse's archiving mode.
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11. |
How can you enable automatic archiving? |
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Shut the database
Backup the database
Modify/Include LOG_ARCHIVE_START_TRUE in init.ora file.
Start up the databse.
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12. |
How can we specify the Archived log file name format and
destination? |
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By setting the following values in init.ora file.
LOG_ARCHIVE_FORMAT = arch %S/s/T/tarc (%S - Log sequence
number and is zero
left paded, %s - Log sequence number not padded. %T -
Thread number lef-zero-paded and %t - Thread number not
padded). The file name created is arch 0001 are if %S is
used.
LOG_ARCHIVE_DEST = path.
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13. |
What is the use of ANALYZE command? |
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To perform one of these function on an index,table, or
cluster:
- to collect statisties about object used by the
optimizer and store them in the data dictionary.
- to delete statistics about the object used by object
from the data dictionary.
- to validate the structure of the object.
- to identify migrated and chained rows of the table or
cluster.
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