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Franck Pachot

Data Guard: always set db_create_file_dest on the standby

By | Oracle | No Comments

The file name convert parameters are not dynamic and require a restart of the instance. An enhancement request was filled in 2011. I mentioned recently on Twitter that it can be annoying with Active Data Guard when a file on the primary server is created on a path that has no file name conversion. However, Ian Baugaard mentioned that there is a workaround for this specific case because db_create_file_dest is dynamic:  

 
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Franck Pachot

Multitenant, PDB, ‘save state’, services and standby databases

By | Oracle | No Comments

Creating – and using – your own services has always been the recommendation. You can connect to a database without a service name, though the instance SID, but this is not what you should do. Each database registers its db_unique_name as a service, and you can use it to connect, but it is always better to create your own application service(s). In multitenant, each PDB registers its name as a service, but the recommendation is…

 
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Clemens Bleile

Transfer redo in async-mode to the Gold/Master copy of the Production DB for ACFS snapshots

By | Database Administration & Monitoring | 2 Comments

If you store your databases on the cluster filesystem ACFS you may use the provided Perl-script gDBClone from OTN to clone databases or create snapshot databases. It is an interesting approach to create clones from the Production DB in minutes regardless of the production DB size. What you do is to create a standby DB from your production DB on a separate cluster and use that standby DB as a Gold/Master copy for ACFS snapshots….

 
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Franck Pachot

Archivelog deletion policy on Data Guard configuration

By | Oracle | 2 Comments

The deletion policy on a dataguard configuration should be: CONFIGURE ARCHIVELOG DELETION POLICY TO APPLIED ON ALL STANDBY; for the site where you don’t backup. It can be the standby or the primary. and: CONFIGURE ARCHIVELOG DELETION POLICY TO APPLIED ON ALL STANDBY BACKED UP 1 TIMES TO DISK; for the site where you do the backups. It can be the primary or the standby. I’ve always configured it in this way, but I recently…

 
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Franck Pachot

12c nologging and Data Guard

By | Database management | 4 Comments

The title sounds weird because Data Guard synchronisation is based on the redo stream, so it makes no sense to do nologging operations on the primary. And this is the reason why we set FORCE LOGGING on a Data Guard configuration. However, to lower the downtime of a migration done with Data Pump, you may want to import with minimal logging and then re-synchronize the standby. This post is about the re-synchronisation in 12.1  

 
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Oracle Team

Oracle 12c – How to Recover lost DataGuard Broker Configuration Files

By | Database Administration & Monitoring, Database management | No Comments

If you are using RMAN to back up your database, you are already doing the right thing. However, RMAN does not take care of everything. e.g. it is not backing up the following things, to mention just a few. Oracle Home Grid Infrastructure Home Data Guard broker files Password File SQL*Net file like ldap.ora, sqlnet.ora, tnsnames.ora and listener.ora /etc/oratab OS audit files Wallets /etc/sysctl.conf and limits.conf OLR and OCR Voting Disks ASM Metadata passwd, shadow,…

 
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Franck Pachot

12cR2: Recover nonlogged blocks after NOLOGGING in Data Guard

By | Database Administration & Monitoring | No Comments

You can accept to do NOLOGGING operations on bulk loads or index build according that you do a backup just after, and that your recovery plan mentions how to load the data again in case of media recovery. With a standby database, we usually force logging because we want redo to be generated for all operations in order to ship it and apply it on standby database. 12.2 brings a new solution: do nologging operations,…

 
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Franck Pachot

12cR2 DBCA can create a standby database

By | Database Administration & Monitoring | No Comments

Do you like DBCA to create a database from command line, with -silent -createDatabase? On a simple command line you can provision a database, with oratab, tnsnames.ora directory creation and any setting you want. And you can even call a custom script to customize further. But if you want to put it in Data Guard, you have to do the duplicate manually with RMAN. This evolves in 12.2 with a new option in DBCA to…

 
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