安裝ORACLE數(shù)據(jù)庫軟件，dbca安裝數(shù)據(jù)庫后，需要配置listener連接數(shù)據(jù)庫。這里有一些概念比較難理解，記錄一些分析實戰(zhàn)結(jié)論。
從連接端講起。
1 連接數(shù)據(jù)庫的方式
oracle的連接串有幾部分構(gòu)成，這里就按sqlplus為例，一個完成的連接串遵循下面格式
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sqlplus 用戶名/密碼@主機:端口號/SID 可選as sysdba |
下面先講只有l(wèi)istener沒有tns的情況
2 listener
使用listener連接需要配置完整連接信息，這里分為兩種連接方式，我們看一個listener的例子：
（帶sid的listener使用netmgr增加listener的datavase services即可出現(xiàn)sid的配置）
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LISTENER2 = (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = iZbp1d4tisi44j6vxze02fZ)(PORT = 1522)) )SID_LIST_LISTENER2 = (SID_LIST = (SID_DESC = (GLOBAL_DBNAME = gdn1400) (ORACLE_HOME = /fdisk1/oracle1400/base/dbhome_1) (SID_NAME = orcl1400) ) )ADR_BASE_LISTENER2 = /fdisk1/oracle1400/baseLISTENER1 = (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = iZbp1d4tisi44j6vxze02fZ)(PORT = 1521)) )ADR_BASE_LISTENER1 = /fdisk1/oracle1400/base |
這里有兩個listener，有sid的叫做靜態(tài)listener，沒有sid的叫做動態(tài)listener。在查看狀態(tài)時存在區(qū)別：
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lsnrctl status listener1...Services Summary...Service "orcl1400" has 1 instance(s). Instance "orcl1400", status READY, has 1 handler(s) for this service...Service "orcl1400XDB" has 1 instance(s). Instance "orcl1400", status READY, has 1 handler(s) for this service...The command completed successfullylsnrctl status listener2...Services Summary...Service "gdn1400" has 1 instance(s). Instance "orcl1400", status UNKNOWN, has 1 handler(s) for this service...The command completed successfully |
注意對于lsnrctl來說，service的名字是global database name
我們在看一個連接串：
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sqlplus sys/password@iZbp1d4tisi44j6vxze02fZ:1521/orcl1400 as sysdba |
這個連接串中最需要關(guān)注的就是服務(wù)名了，這里是orcl1400。
注意！：這個服務(wù)名必須由listener中的某一個提供，這里listener2的服務(wù)名提供的是gdn1400，而listener1沒有提供服務(wù)名。那么如何連接數(shù)據(jù)庫呢？答案就是走listener1的連接會去數(shù)據(jù)庫中動態(tài)的查詢服務(wù)名（所以叫做動態(tài)連接）
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SQL> show parameter serviceNAME TYPE VALUE------------------------------------ ----------- ------------------------------service_names string orcl1400 |
也就是為什么使用orcl1400能連上數(shù)據(jù)庫。這里我們使用靜態(tài)連接試一下，也是可以連接數(shù)據(jù)庫的（注意端口號和動態(tài)的不同）
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sqlplus sys/password@iZbp1d4tisi44j6vxze02fZ:1522/gdn1400 as sysdbaSQL*Plus: Release 12.1.0.2.0 Production on Thu May 30 20:51:00 2019Copyright (c) 1982, 2014, Oracle. All rights reserved.Connected to:Oracle Database 12c Enterprise Edition Release 12.1.0.2.0 - 64bit ProductionWith the Partitioning, OLAP, Advanced Analytics and Real Application Testing optionsSQL> |
3 TNS
那么tns是什么呢？我們看下這個連接串。
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sqlplus sys/password@iZbp1d4tisi44j6vxze02fZ:1521/orcl1400 as sysdba |
@后面的信息很多，能否省略呢？比如
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sqlplus sys/password@tns1400 as sysdba |
這樣看起來簡潔很多也便于管理，TNS即實現(xiàn)了這個功能，我們看一個tnsnames.ora的配置：
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NSN1522 = (DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)(HOST = iZbp1d4tisi44j6vxze02fZ)(PORT = 1522)) ) (CONNECT_DATA = (SERVICE_NAME = gdn1400) ) )NSN1521 = (DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)(HOST = iZbp1d4tisi44j6vxze02fZ)(PORT = 1521)) ) (CONNECT_DATA = (SERVICE_NAME = orcl1400) ) ) |
這里可以看到，最左面的NSN1522和NSN1521就是我們可以@的服務(wù)名字。內(nèi)部的映射信息是指向listener的，這里的servicename要和上面的global database name對應(yīng)上！
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NSN1522, iZbp1d4tisi44j6vxze02fZ, 1522, gdn1400 -----> listener2NSN1521, iZbp1d4tisi44j6vxze02fZ, 1521, orcl1400 -----> listener1 |
兩個別名指向了兩個不同的listener，連接測試：
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# sqlplus sys/password@nsn1521 as sysdbaSQL*Plus: Release 12.1.0.2.0 Production on Thu May 30 20:58:51 2019Copyright (c) 1982, 2014, Oracle. All rights reserved.Connected to:Oracle Database 12c Enterprise Edition Release 12.1.0.2.0 - 64bit ProductionWith the Partitioning, OLAP, Advanced Analytics and Real Application Testing optionsSQL># sqlplus sys/password@nsn1522 as sysdbaSQL*Plus: Release 12.1.0.2.0 Production on Thu May 30 20:58:55 2019Copyright (c) 1982, 2014, Oracle. All rights reserved.Connected to:Oracle Database 12c Enterprise Edition Release 12.1.0.2.0 - 64bit ProductionWith the Partitioning, OLAP, Advanced Analytics and Real Application Testing optionsSQL> |
注意：tns依賴lsnrctl使用，可以理解為hostname這樣的概念，注意tns的SERVICE_NAME等信息必須和listener關(guān)聯(lián)才能連接！
以上就是本文的全部內(nèi)容，希望對大家的學(xué)習(xí)有所幫助，也希望大家多多支持服務(wù)器之家。
原文鏈接：https://segmentfault.com/a/1190000020395535
