SET TRANSACTION USE ROLLBACK SEGMENT rbs_name

a control file is used to control the data file and the redo
log file. this contains the information of the path of the
datafile and the redo log file. we can recover a datafie or
a redolog file which is currupted by the control file.

A control file is used to control the data file and the redo
log file. this contains the information for the path of the
datafile and the redo log file. we can recover a data file 
or a redo log file Which is corrupted by the control file.

It  will  try  to  fit  the transaction in a cyclic fashion
to all existing extents.  Once it found an extent is in use
then it forced to acquire a new extent (No. of extents is
based on the optimal size)

Calculate the total header size
Calculate the available dataspace per data block
Calculate the combined column lengths of the average row
Calculate the total average row size.
Calculate the average number rows that can fit in a block
Calculate the number of blocks and bytes required for the table.

After  arriving the calculation, add 10 % additional space
to calculate the initial extent size for a working table.

Export the user

Perform import  using  the  command  imp  system/manager  
file=export.dmp indexfile=newrite.sql. This will create all
definitions into newfile.sql.

Drop necessary objects.

Run the script newfile.sql after altering the tablespaces.

Import from the backup for the necessary objects.

shutdown the database
copy the existing control file by using copy command of OS.
paste it another location where you want to create it.
define the path in init.ora file ("control file" Parameter)
startup database.

It  is  a  measure  of  well the data cache buffer is
handling requests for data.

Hit Ratio = (Logical Reads - Physical Reads - Hits Misses)/
Logical Reads.

shared pool (data dictionary and library cache), buffer
cache,  redo log buffer

SGA constists of

1)Shared Pool => Components 
                  a)Library Cache
                  (Shared SQL Area/ & Shared PL SQL Area)
                  b)Dictionary cache 
                   
2)Database Buffer Cache 
3)Redo Log Buffer
4)Large Pool
5)Java Pool

shared pool contains both the data dictionary and the
library cache which are used for checking the syntax and the
execution plan respectively.

Memory area of oracle which consists of Library cache
(recently executed sql and pl/sql statements) and Data 
Dictionary cache(recently used tables and indexes).

IT IS A MEMORY STRUCTURE WHICH CONTAINS 
1.)LIBRARY CACHE(HOLDS RECENTLY EXECUTED PL/SQL COMMANDS)
2.)DATA DICTIONARY CACHE(HOLDS ALL RECENTLY EXECUTED DDL 
COMMANDS);

Dedicated Server Configuration and 
Multi-threaded Server Configuration

Lock (LCKn) are used for inter-instance locking when the ORACLE 
Parallel Server option is used. 

the process monitor(pmon) is used to monitor the
transactional  flow in the sga and after the transaction is
over, it tells the next transaction to enter into the sga.

PMON IS RESPONSIBLE FOR RELEASEING THE RESOURCE OCCUPIED BY 
THE USER WHEN THERE IS A ABNORMAL TERMINATION OF USER.

pmon is used in releasing of locks and latches. Locks are 
put on tables and latches are put on memory.

In additon to the above, when a transaction causes a 
process to fail, PMON will initiate a ROLLBACK for that 
transaction.

Though a single LCK process is sufficient for most Parallel
Server systems upto Ten Locks (LCK0,....LCK9) are used for
inter-instance locking

Dispatcher (Dnnn) process is responsible for routing requests 
from connected user processes to available shared server
processes and returning the responses back to the
appropriate user processes

DISPATCHER WILL ACTIVE ONLY IN SHARED SERVER.

RESPONSIBLE FOR THE REQUEST AND RESPONSE OF USERS FOR 
MINIMISING THE LODE ON SINGLE THREAD  AND CREATES VRITUAL 
CIRCUITS IN PROCESSING.

FIRST TIME ...........

log writer is used to write the commited or uncommited data
from the redolog buffer to the redo log file.