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Oracle Team

Oracle Team

Delphix: a glossary to get started

By | Oracle | No Comments

By Franck Pachot . dbi-services is partner of Delphix – a data virtualization platform for easy cloning of databases. I’m sharing a little glossary to get started if you are not familiar with the terms you see in doc, console or logs. Setup console The setup console is the first interface you will access when installing Delphix engine (“Dynamic Data Platform”). You import the .ova and start it. If you are on a network with…

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Oracle Team

Oracle Rolling Invalidate Window Exceeded(3)

By | Oracle | One Comment

By Franck Pachot . This extends a previous post (Rolling Invalidate Window Exceeded) where, in summary, the ideas were: When you gather statistics, you want the new executions to take into account the new statistics, which means that the old execution plans (child cursors) should be invalidated You don’t want all child cursors to be immediately invalidated, to avoid an hard parse storm, and this is why this invalidation is rolling: a 5 hour window…

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Oracle Team

Oracle DB on Azure with Multitenant Option

By | Cloud | 3 Comments

By Franck Pachot . If you want to run an Oracle Database in the Microsoft Azure cloud, you will install it yourself on a VM. And then, you can expect the same as when you install it in your premises, in a virtual environment. Except that Oracle makes it two times more expensive by accepting to license the processor metric on vCPUs at the condition that the Intel core factor is not applied. And in…

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Oracle Team

Learn ODA on Oracle Cloud

By | Oracle | No Comments

By Franck Pachot . You want to learn and practice your ODA command line and GUI without having an ODA at home? It should be possible to run the ODA image on VirtualBox but that’s probably a hard work as it is tied to the hardware. About the configuration, you can run the Oracle Appliance Manager Configurator on your laptop but I think it is not compatible with the latest odacli. However, for a long…

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Oracle Team

19c serverless logon trigger

By | Oracle | No Comments

By Franck Pachot . I thought I already blogged about this but can’t find it. So here it is, with a funny title. I like to rename oracle features by their user point of view (they are usually named from the oracle development point of view). This is about setting session parameters for Oracle connections, directly from the connection string, especially when it cannot be set in the application (code) or in the DB server…

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Oracle Team

Pressure Stall Information on Autonomous Linux

By | Database Administration & Monitoring | No Comments

By Franck Pachot . The Linux metrics that are usually considered for performance monitoring and troubleshooting have many drawbacks and frequent misinterpretations. The recent kernels provide PSI (Pressure Stall Information) which is not enabled by default in Oracle Linux “unbreakable” kernel. However, the kernel is compiled with it. Here is how to enabled it in a newly create Autonomous Linux instance (the Oracle Cloud Linux ,based on OEL 7.9, with no-downtime patching) Check PSI availability…

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Oracle Team

Optimizer Statistics Gathering – pending and history

By | Oracle | No Comments

By Franck Pachot . This was initially posted to CERN Database blog on Wednesday, 12 September 2018 where it seems to be lost. Here is a copy thanks to web.archive.org Demo table I create a table for the demo. The CTAS gathers statistics (12c online statistics gathering) with one row and then I insert more rows: 10:33:56 SQL> create table DEMO as select rownum n from dual; Table DEMO created. 10:33:56 SQL> insert into DEMO…

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Oracle Team

Password rolling change before Oracle 21c

By | Oracle | One Comment

By Franck Pachot . You may have read about Gradual Password Rollover usage from Mouhamadou Diaw and about some internals from Rodrigo Jorge. But it works only on 21c which is only in the cloud, for the moment, in Autonomous Database and DBaaS (but here I’ve encountered some problems apparently because of a bug when using SQL*Net native encryption). But your production is not yet in 21c anyway. However, here is how you can achieve…

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Oracle Team

Oracle SPD status on two learning paths

By | Oracle | No Comments

By Franck Pachot . I have written a lot about SQL Plan Directives that appeared in 12c. They were used by default and, because of some side effects at the time of 12cR1 with legacy applications that were parsing too much, they have been disabled by default in 12cR2. Today, there are probably not used enough because of their bad reputation from those times. But for datawarehouses, they should be the default in my opinion….

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Oracle Team

Efficiently query DBA_EXTENTS for FILE_ID / BLOCK_ID

By | Oracle | 4 Comments

By Franck Pachot . This was initially posted to CERN Database blog on Thursday, 27 September 2018 where it seems to be lost. Here is a copy thanks to web.archive.org Did you ever try to query DBA_EXTENTS on a very large database with LMT tablespaces? I had to, in the past, in order to find which segment a corrupt block belonged to. The information about extent allocation is stored in the datafiles headers, visible though…

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