Network configuration
Listener is utility which listens for incoming request at particular port and then hands of the connection to database. Main network configuration files are located in %oracle_home%/NETWORK/Admin/ directory and are the following
listener.ora -For configuration of Listeners, and the SID's to listen for
sqlnet.ora -Miscellaneous Naming methods, how to perform authenticaton
tnsnames.ora -local naming methods, creat alias for datbase, --Below SID_LIST_LISTENETR is the list of SID's the listerner LISTERNER is
--listening to SID_LIST_LISTENER=
( SID_LIST= (SID_DESC= (SID_NAME=orcl) (ORACLE_HOME=/oracle9i) ) (SID_DESC= (SID_NAME=sales) (ORACLE_HOME=/oracle9i) ) )
---This is the listener LISTENER configured which is listening to above sids ---You could rename. You could configure multiple listener on same server ---but with different ports ofcourse. LISTENER= (DESCRIPTION= (ADDRESS_LIST= (ADDRESS=(PROTOCOL=tcp)(HOST=myserver)(PORT=1521)) ) ) Distributed Queries, A database link is a schema object in one database that enables you to access objects on another database We have two types of db links public and private. Public : Link is accesible to all users. Private : Other users cant access create public database link OTHERDB connect to scott identified by tiger using '<tns of OTHERDB>' if you dont use public it is private and is owned by the current user. To check if the other db in working select sysdate from dual@OTHERDB; should return the date as in other database. Now the db links has been created you could use the db link to access/modify the data across the other database using distributed Queries To get list of all the db links on the database
SET LINES 120
COLUMN db_link FORMAT A20 COLUMN host FORMAT A25 SELECT owner, db_link, username, host FROM dba_db_links ORDER BY owner, db_link; To get the creation script of the available db links on the database
SELECT 'create '||DECODE(U.NAME,'PUBLIC','public ')||'database link '||CHR(10) ||DECODE(U.NAME,'PUBLIC',Null, U.NAME||'.')|| L.NAME||chr(10) ||'connect to ' || L.USERID || ' identified by ''' ||L.PASSWORD||''' using ''' || L.host || '''' ||chr(10)||';' TEXT FROM sys.link$ L, sys.user$ U WHERE L.OWNER# = U.USER# ; |
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