mylearning4oracle

What are Database Link: ======================= A database link is one way method of accesing a remote database from other database provided the link should be existing in the dictionary of the local database. We usually create a DB link based on the DB global database name. eg: == A database link connection is one-way in the sense that a client connected to local database A can use a link stored in database A to access information in remote database B, but users connected to database B cannot use the same link to access data in database A. If local users on database B want to access data on database A, then they must define a link that is stored in the data dictionary of database B. A database link connection allows local users to access data on a remote database. For this connection to occur, each database in the distributed system must have a unique global database name in the network domain. The global database name uniquely identifies a database server in a distribu...

Golden gate: =========== Golden gate software was founded in the year 1995 and name after famous golden gate bridge Golden gate was founded by eric fish and tod davidson Golden gate features: ==================== Real time data replication is one of the basic feature of golden gate It provides high availability by acting as live stand-by target for a primary target It provides  zero downtime upgrades and migrations It provides live reporting for the operational databases Golden gate Processes: ===================== Manager process Extract Process(capture process) replicat Process Trail files Data Pump Server Collector Extract Process: =============== It reads the data from the online redo logs of the database and typically does not require connection to the database. The extract process will regularlily checkpoint its read and write position, typically to a file. Trail  Files:- ============ Trail files basically contains the canonical format o...

Oracle Kernel Parameters: ======================== We have different kernel parameters  SHM means shared memory segments , which are being used by the SGA shmax ->  It defines the maximum size of shared memory segment shmin ->  It defines the minimum size of shared memory segment shmni ->  It defines the maximum  number of shared memeory segments available on the system shmall -> It defines the total amoumnt of shared memory allocated  on the system Semaphore , it is a way of locking or applying flag on shared memory semmsl -> number of semaphores per set semmns -> total number of available semaphores semopm -> number of operations can be performed per semaphore call file_max -> defined number of files can be opened at once ip_local_port_range -> defines the port range rmem_default and rmem_max -> defines the min and max size of receive buffer wmem_default and wmem_max -> defines the min and max siz...