Data Guard

How to Duplicate a 19c Physical Standby Database

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You don’t have to create an empty database on the standby server for building a standby database. In this post, I will show you how to duplicate a 19c physical standby database from scratch by the following sections. Password File File Management Mode Parameter File Necessary Directories Name Resolution Connect Identifiers Listeners Force Logging RMAN […]
Data Guard

How to Build Asymmetric Standby Database for Data Guard

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Asymmetric Data Guard Usually we build data guard environments with the symmetric architecture design on primary and standby servers, that is, single-instance to single-instance or RAC to RAC. Practically, we could have downgraded standby servers in hardware specifications. For example, we may use 16 cores per instance on the primary side but use 8 cores […]
TNS Name

How to Connect Without TNSNAMES

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Connect No TNSNAMES Yes, sometimes we are not allowable to change tnsnames.ora, even a tiny bit. How can we connect to new or moved databases? In this post, I provided some ways to connect to databases without touching the original tnsnames.ora. Use Full Connect Descriptor Use Your Own tnsnames.ora Use Easy Connect Method 1. Use […]
Data Guard

Connect-Time Failover to Standby Database

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We’re going to introduce 3 ways that can failover to a standby database at connect-time in this post. Using a Persistent Service Name Using a Dynamic Service Name Using a SRVCTL Configured Service Using a Persistent Service Name Connect-Time Failover is a feature of local naming method, and can be easily set up by adding […]
Database Link

What DB Link Can and Cannot Do

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DB Link For better understanding the features of a database link which may play an important role in data migration, we should study what a database link can and cannot do in a distributed database system in order to develop our data migration strategy. Generally speaking, you can perform Data Query Language (DQL) and Data […]
SQLNET

How to Resolve TNS-12545: Connect failed because target host or object does not exist

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TNS-12545 Let’s see how we reproduce TNS-12545. C:\Users\ed>tnsping compdb TNS Ping Utility for 64-bit Windows: Version 12.1.0.1.0 – Production on 21-JUL-2014 19:10:59 Copyright (c) 1997, 2013, Oracle.  All rights reserved. Used parameter files: C:\oracle\app\client\ed\product\12.1.0\client_1\network\admin\sqlnet.ora Used TNSNAMES adapter to resolve the alias Attempting to contact (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = primary01)(PORT = 1521)) […]
SQLNET

How to Resolve TNS-03505: Failed to resolve name

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TNS-03505 Failing to resolve TNS names could involve any one of the network configuration files, such as tnsnames.ora or sqlnet.ora. There’re several possible causes may throw TNS-03505: Absent Local Naming Method Missing tnsnames.ora File Connect Identifier Mismatch Searching for Wrong Domain 1. TNS-03505 due to Absent Local Naming Method There’re several naming methods supported by […]
DNS

sqlplus, tnsping or lsnrctl Hangs

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sqlplus, tnsping or lsnrctl Hangs I can’t cover all situations in this post, but I have some cases that can share with you. Those hanging all point to one problem: Domain name resolution. Does the database server use DNS to do name resolution? Sometimes, DNS traps the name resolution in an unknown and indefinite loop […]