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Jan 08 2020
Clemens Bleile

ARRAYSIZE or ROWPREFETCH in sqlplus?

By | Database Administration & Monitoring | No Comments

ARRAYSIZE or ROWPREFETCH in sqlplus? What is the difference between the well known sqlplus-setting arraysize and the new sqlplus-12.2.-feature rowprefetch? In Blog https://blog.dbi-services.com/oracle-fasttrue-in-sqlplus-some-thoughts-about-rowprefetch/ I showed a case, which helps to reduce the logical IOs when using rowprefetch. Here the definition of arraysize and rowprefetch according the documentation: arraysize: SET System Variable Summary: Sets the number of rows, called a batch, that SQL*Plus will fetch from the database at one time. Valid values are 1 to…

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Jan 06 2020
Clemens Bleile

Oracle FAST=TRUE in sqlplus? Some thoughts about rowprefetch

By | Database Administration & Monitoring | No Comments

During my time as a Consultant working on Tuning Tasks I had the feeling that many people think that there is an Oracle-parameter “FAST=TRUE” to speed up the performance and throughput of the database calls. Unfortunately such a parameter is not available, but since version 12cR2 Oracle provided the option “-F” or “-FAST” for sqlplus, which looks like a “FAST=TRUE”-setting. Here an excerpt from the documentation: The FAST option improves general performance. This command line…

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Dec 02 2019
Daniel Westermann

Real time replication from Oracle to PostgreSQL using Data Replicator from DBPLUS

By | Database Administration & Monitoring | No Comments

I’ve done quite some real time logical replication projects in the past, either using Oracle Golden Gate or EDB replication server. Build in logical replication in PostgreSQL (which is available since PostgreSQL 10) can be used as well when both, the source and the target are PostgreSQL instances. While being at the DOAG conference and exhibition 2019 I got in contact with people from DBPLUS and they provide a product which is called “Data Replicator”….

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Nov 29 2019
Jérôme Dubar

Focus on 19c NOW!

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

Introduction For years, Oracle used the same mechanism for database versioning. A major version, represented by the first number. And then a release number, 1 for the very first edition, and a mature and reliable release 2 for production databases. Both of them having patchsets (the last number) and regular patchset updates (the date optionally displayed at the end) to remove bugs and to increase security. Jumping from release 1 to release 2 required a…

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Nov 15 2019
Clemens Bleile

Elapsed time of Oracle Parallel Executions are not shown correctly in AWR

By | Database Administration & Monitoring | 2 Comments

As the elapsed time (time it takes for a task from start to end, often called wall-clock time) per execution of parallel queries are not shown correctly in AWR-reports, I thought I setup a testcase to find a way to get an elapsed time closer to reality. REMARK: To use AWR (Automatic Workload Repository) and ASH (Active Session History) as described in this Blog you need to have the Oracle Diagnostics Pack licensed. I created…

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Oct 23 2019
Marc Wagner

Adding a dbvisit standby database on the ODA in a non-OMF environment

By | Database Administration & Monitoring | No Comments

I have recently been working on a customer project where I had been challenged adding a dbvisit standby database on an ODA X7-2M, named ODA03. The existing customer environment was composed of Oracle Standard 12.2 version database. The primary database, myDB, is running on server named srv02 and using a non-OMF configuration. On the ODA side we are working with OMF configuration. The dbvisit version available at that time was version 8. You need to…

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