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Category Archives: Database Administration & Monitoring

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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Mouhamadou Diaw

Dataguard: QUIZZ on Snapshot Standby

By | Database Administration & Monitoring | No Comments

In oracle documentation we can find this about snapshot standby: A snapshot standby database is a fully updatable standby database that provides disaster recovery and data protection benefits that are similar to those of a physical standby database. The concept of snapshot standby is that we can temporary convert a physical standby to an updatable database for different purposes and then convert back to a physical standby. During the time that the database is a…

 
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Daniel Westermann

Are statistics immediately available after creating a table or an index in PostgreSQL?

By | Database Administration & Monitoring | No Comments

While giving the last PostgreSQL DBA Essentials workshop this question came up: When we create a table or an index: are the statistics available automatically? To be more precise: When we create and load a table in one step, create an index on that table afterwards: Do we have the statistics available by default or do we need to wait for autovacuum to kick in or analyze manually? Lets see …  

 
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Pierre Sicot

DBVISIT from Oracle to Postgres

By | Database Administration & Monitoring | No Comments

As I regularly work on Oracle and PostgreSQL, I decided to test the replication from Oracle to PostgreSQL using the Dbvisit Replicate tool. Dbivisit Replicate does not use Oracle logminer ot triggers but its own mining processes to get the changes when they are written to the redo logs. When a change appears in the redo log, an external file called PLOG is generated and transferred to the target. The architecture is quite easy to…

 
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Clemens Bleile

DOAG 2017: avg_row_len with virtual columns

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

At the DOAG I attended a session “Top-level DB design for Big Data in ATLAS Experiment at CERN” provided by Gancho Dimitrov. The presentation was actually very interesting. As part of Gancho’s improvement activities to reduce space in a table he stored data in a 16 Bytes raw format (instead of a string representing hex values which requires 36 Bytes) and use virtual columns to actually calculate the real hex-string. So the original value is…

 
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Thomas Rein

DOAG 2017

By | Database Administration & Monitoring | No Comments

Als Consultant bei dbi services war ich die letzten 2 Jahre hauptsächlich in Konsolidierungsprojekten basierend auf den Oracle Engineered Systems unterwegs. Deshalb waren für mich natürlich die Vorträge über die neue Generation der Oracle Database Appliance X7-2 interessant. Aus meiner Sicht hat Oracle den richtigen Schritt getan und die Vielfalt der ODA Systeme wie es sie noch in der X6-2 Generation gab (Small/Medium/Large und HA) reduziert. Künftig wird es die ODA X7-2 nur noch in…

 
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Hervé Schweitzer

DOAG2017 my impressions

By | Database Administration & Monitoring | No Comments

As each year at end of November the biggest Oracle European conference takes place in Nürnberg, #DOAG2017. This year is a little bit special, because the DOAG celebrate the 30th edition of the conference. dbi services is for the 5th time present with a booth and 8 sessions at the DOAG. During the last 2 days I already followed many sessions, and I want to give you my impression and feedback’s about the market trends….

 
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Daniel Westermann

firewalld rules for Veritas Infoscale 7.3 with Oracle

By | Database Administration & Monitoring | No Comments

You might wonder, but yes, Veritas is still alive and there are customers that use it and are very happy with it. Recently we upgraded a large cluster from Veritas 5/RHEL5 to Veritas InfoScale 7.3/RHEL7 and I must say that the migration was straight forward and very smooth (when I have time I’ll write another post specific to the migration). At a point in time during this project the requirement to enable the firewall on…

 
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