RAM&KRISHNA BLOG

C:\Users\>sqlplus SQL*Plus: Release 10.2.0.1.0 - Production on Thu Jun 11 20:55:55 2013 Copyright (c) 1982, 2005, Oracle.  All rights reserved. Connected to: Oracle Database 10g Express Edition Release 10.2.0.1.0 - Production SQL> create user exp identified by exp; User created. SQL> create user imp identified by imp; User created. SQL> grant dba to exp; Grant succeeded. SQL> grant dba to imp; Grant succeeded. SQL> conn exp Enter password: Connected. SQL> SQL> create table Test (col1 char(10)); Table created. SQL> grant select on Test to rishi; Grant succeeded. SQL> insert into Test values('hello'); 1 row created. SQL> commit; Commit complete. NOTE:Directory already exists. So used the existng one SQL> select * from dba_directories; OWNER                          DIRECTORY_NAME ------------------------------ ------------------------------ DIRECTORY_PATH ---------------------------------

Due to maximum number of sessions exceeded in XXXX database. Hence we have received the following error. ORA-12519: TNS:no appropriate service handler found Solution: Seems the number of processes parameter value less. Its unable to create new session. Because its reached maximum sessions. Please check like below. SQL> select * from v$resource_limit where RESOURCE_NAME in ('sessions','processes','transactions'); RESOURCE_NAME                  CURRENT_UTILIZATION      MAX_UTILIZATION         INITIAL_ALLOCATION             LIMIT_VALUE ----------------------         -------------------   ---------------------    -----------------------   ------------------------------ processes                             177                    180                        180                         180 sessions                              198                    203                        203                         203 Close the unwanted sessions

DATA  GUARD Data Guard is basically a ship redo and then apply redo, as you know redo is the information needed to recover a database transaction. A production database referred to as a primary database transmits redo to one or more independent replicas referred to as standby databases. Redo information needed to recover a database transaction. Remember that the LGWR can write to the log file using "group" commits, basically entire list of redo entries of waiting transactions (not yet committed) can be written to disk in one operation, thus reducing I/O. Even through the data buffer cache has not been written to disk, Oracle guarantees that no transaction will be lost due to the redo log having successfully saved any changes. A production database referred to as a primary database transmits redo to one or more independent replicas referred to as standby databases. A standby database will also automatically re synchronize if it becomes temporary disconnected

STARTUP UPGRADE ------------------------------- Starts the database in OPEN UPGRADE mode and sets system initialization parameters to specific values required to enable database upgrade scripts to be run. UPGRADE should only be used when a database is first started with a new version of the Oracle Database Server. STARTUP RESTRICT ----------------------------- Only enables Oracle Database users with the RESTRICTED SESSION system privilege to connect to the database. Later, you can use the ALTER SYSTEM command to disable the restricted session feature. STARTUP FORCE ------------------------ Shuts down the current Oracle Database instance (if it is running) with SHUTDOWN mode ABORT, before restarting it. If the current instance is running and FORCE is not specified, an error results. FORCE is useful while debugging and under abnormal circumstances. It should not normally be used. SQL> STARTUP FORCE; ORACLE instance started. Total System Global Area  805306368 bytes