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Franck Pachot

Oracle 12cR2: Online tablespace encryption

By | Database Administration & Monitoring | One Comment

By default, all data is visible in the datafiles. Transparent Tablespace Encryption (TDE) can be used to get them encrypted. It requires Enterprise Edition plus Advanced Security Option. Except in the Oracle Cloud when it is available – and mandatory – in all editions. And we can foresee that security policies will be enforced in the future years, by law or because companies realize their files can be stolen. This means that lot of databases…

 
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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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William Sescu

Oracle 12c – Recreating a Controlfile in a Data Guard environment with noresetlogs

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

Sometimes you might run into situations where the controlfile does not represent the backups and archivelogs correctly, because of a mismatch of the control_file_record_keep_time and the RMAN retention. The controlfile has non circular and a circular records. Non circular are e.g. database information, redo threads, datafiles and so on. These non circular records don’t age out, however, they can be reused, e.g. when a tablespace is dropped. The circular records are e.g. the log history,…

 
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Franck Pachot

12cR2: lockdown profiles and ORA-01219

By | Database Administration & Monitoring | One Comment

When you cannot open a database, you will get some users unhappy. When you cannot open multitenant database, then the number of unhappy users is multiplied by the number of PDBs. I like to encounter problems in my lab before seeing them in production. Here is a case where I’ve lost a file. I don’t care about the tablespace, but would like to put it offline and at least be able to open the database….

 
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William Sescu

Oracle 12c – How to correct the error: “RMAN-20005: target database name is ambiguous”

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

I do have a Data Guard environment, where I have configured the RMAN DB_UNIQUE_NAME persistent setting for my primary and the standby. With the RMAN DB_UNIQUE_NAME settings I am able to run reports my Oracle Data Guard environment from any database. I could e.g. list all archivelogs for SITE1 from SITE2 or the other ways around. Or I could show all persistent settings for SITE1 from SITE2 and of course the other way around. The…

 
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Franck Pachot

12cR2 real-time materialized view (on query computation)

By | Database Administration & Monitoring | 2 Comments

Materialized views is a very old feature (you may remember that it was called snapshots a long time ago). It has all advantages of a view, as you can define any select statement that joins, filters, aggregates, and see it as one table. It has all advantages of a table, as it is stored in one segment, can be indexed, partitioned, have constraints, be compressed, etc. It looks like indexes as it stores data redundantly,…

 
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William Sescu

Oracle 12c – Combining Flashback Drop and Flashback Query

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

If you think that Flashback Drop feature just brings back your table, then this is only half of the story. It does much more than that. Besides undropping the table, it also brings back your constraints, your indexes, your trigger, your grants and the statistics as well. The ugly part is, that the flashback drop brings back some strange object names e.g. your indexes and constraints with names like “BIN$…” or alike. Maybe something you…

 
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William Sescu

Oracle 12c – Issues with the HEATMAP Segment even if the heat map feature is not used

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

When I don’t need I feature, I don’t turn it on, or do not use it because it reduces the possibility to run into issues. Most of the times this is true, however, during the preparation for an RMAN workshop, the RMAN list failure command showed me the following dictionary issue. RMAN> list failure; using target database control file instead of recovery catalog Database Role: PRIMARY List of Database Failures ========================= Failure ID Priority Status…

 
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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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