关于TNSNAMES.ORA中SERVICE_NAME，SID的一点理解
SID只指定一个实例，而SERVICE_NAME在RAC环境中指定多个实例。
如下，该配置指定了一个节点的HOST：
RAC1 =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = 10.122.12.16)(PORT = 1521))
)
(CONNECT_DATA =
(SERVICE_NAME = RAC)
)
)
如下，运行在10.122.12.16的实例是rac1:
[oracle@RAC01 ~]$> 64 bytes from oracle账号RAC01 (10.122.12.16): icmp_seq=2 ttl=64 time=0.026 ms
— RAC01> [oracle@RAC01 ~]$ ps -ef| grep ora_
oracle 1981 1 0 Jun19 ? 00:02:01>
以下有更详细的解释，转载自https://www.dba-oracle.com/t_oracle_sid_instance_name_service_name.htm
Question: What> (DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS =
(COMMUNITY = TCP)
(PROTOCOL = TCP)
(HOST = 123.45.6789)
(PORT = 1521)
)
)
(CONNECT_DATA =
(SERVER=dedicated)
(SERVICE_NAME => (DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS =
(COMMUNITY = TCP)
(PROTOCOL = TCP)
(HOST => )
)
(CONNECT_DATA = (SID =>
NAME VALUE
——- ———————————————-
db_name>
select
> (DESCRIPTION =
(ADDRESS =
(PROTOCOL = TCP)
(HOST => )
(CONNECT_DATA =
(SERVICE_NAME => (SID_LIST =
(SID_DESC =
(SID_NAME => )
(SID_DESC =
(GLOBAL_DBNAME => (SID_NAME = mysid)
)
)
)
global_name – If>
select *
from
global_name;
GLOBAL_NAME
—————————————
MYSID.REMOTE.DBA.NET