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12.2 Archives - Page 2 of 5 - Blog dbi services

Joël Cattin

Oracle 12cR2 : Optimizer Statistics Advisor

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

The Optimizer Statistics Advisor is a new Advisor in Oracle 12.2. The goal of this Advisor is to check the way you gather the statistics on your database, and depending on what is found, it will makes some recommendations on how you can improve the statistics gathering strategy in order to provide more efficient statistics to the CBO. This Advisor is also able to generate remediation scripts to apply the statistics gathering “best practices”. The…

 
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Franck Pachot

12cR2 RMAN> REPAIR

By | Database management | One Comment

By Franck Pachot . Do you know the RMAN Recovery advisor? It detects the problems, and then you: RMAN> list failure; RMAN> advise failure; RMAN> repair failure; You need to have a failure detected. You can run Health Check if it was not detected automatically (see https://blog.dbi-services.com/oracle-12c-rman-list-failure-does-not-show-any-failure-even-if-there-is-one/). In 12.2 you can run the repair directly, by specifying what you want to repair.  

 
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Franck Pachot

12cR2 DML monitoring and Statistics Advisor

By | Database management | No Comments

By Franck Pachot . Monitoring DML to get an idea of the activity on our tables is not new. The number of insert/delete/update/truncate since last stats gathering is tracked automatically. The statistics gathering job use it to list and prioritize tables that need fresh statistics. This is for slow changes on tables. In 12.2 we have the statistics advisor that goes further, with a rule that detects volatile tables: SQL> select * from V$STATS_ADVISOR_RULES where…

 
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Franck Pachot

12cR2: TNS_ADMIN in env.ora

By | Database Administration & Monitoring | No Comments

By Franck Pachot . The network files (sqlnet.ora, tnsnames.ora, lsnrctl.ora) are read by default from ORACLE_HOME/network/admin but you may have several Oracle installations, and want only one place for those files. Then you can use TNS_ADMIN environment variable. But are you sure that it is always set when starting the database? the listener? the client? They must be consistent (see https://blog.dbi-services.com/oracle-12cr2-plsql-new-feature-tnsping-from-the-database/). Then what we do for the cases where TNS_ADMIN is not set: define symbolic…

 
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Franck Pachot

Oracle 12cR2, RAC, Cloud, ACFS, PDB thin clones and asmadmin

By | Cloud, Database Administration & Monitoring | No Comments

By Franck Pachot . In the Oracle Public Cloud, fast provisioning gets all its meaning when creating a RAC database service: in one hour you can get an operational highly available multitenant database. You can even create it in Data Guard for Disaster Recovery. Now, Oracle is pushing ACFS to store the datafiles rather than direct ASM. Especially in multitenant because a great feature is thin cloning: CREATE PLUGGABLE DATABASE AS SNAPSHOT COPY. However, I…

 
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Franck Pachot

Oracle 12cR2: Online tablespace encryption

By | Database Administration & Monitoring | One Comment

By Franck Pachot . 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…

 
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