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I have recently come across an issue with one of my customer that told me that their SQL Server 2008 R2 instance had a memory leak. These are strong words! The server has 64 GB of RAM and the concerned SQL Server instance is limited to 54 GB according to the max server memory (GB) server option. However, he noticed…
By Franck Pachot . Here is an odd Oracle behavior I observed when a transaction that acquired a lock is rolled back. Note that this is related to a specific combination of locks that should not be encountered in production. So it’s not a bug. Just something unexpected. First session In my first session I lock the DEPT table…
By Franck Pachot . Do you know why Oracle Database is a leader in the database market since 30 years? Do you know any other software that is still the leading solution after decades? I think that it is because Oracle has been a good software from the get-go. Many early decisions in the software architecture have revealed themselves later…
By Franck Pachot . I have recently published a script to check index fragmentation. But then, do you COALESCE or REBUILD? Well, there also is another option: ALTER INDEX SHRINK SPACE. Let’s compare all those index defragmentation operations. Fragmented index I have an index created when the table had 1 million rows. Then, I deleted 90% of the rows. Here…
To remove an agent in the previous Oracle OEM Cloud Control 12c versions, you first had to delete its targets, stop the agent, and remove the host target. Only then were you able to remove the agent. In version 12.1.0.4, the decommission agent feature has been greatly improved. From the agent menu, you select the new feature Agent Decommission: The…
By Franck Pachot . When can we use IOT? That’s a question I had when giving recently the Oracle DBA essentials workshop. the DBA Essential is very dense and there is only half a day about performance. We have the Oracle Performance Tuning workshop to go into those details. But IOTs are under used in my opinion, so I’ll post…
By Franck Pachot . System statistics can be gathered in NOWORKLOAD or WORKLOAD mode. Different values will be set depending on that and the others will be calculated – derived from them. We can see defined values from SYS.AUX_STATS$ but here is a script that shows the calculated ones as well. With no system statistics or NOWORKLOAD the values of…
By Franck Pachot . At Oracle Open World 2014, or rather the Oaktable World, Chris Antognini has presented ‘Indexes: Structure, Splits and Free Space Management Internals’. It’s not something new, but it’s still something that is not always well understood: how index space is managed, block splits, fragmentation, coalesce and rebuilds. Kyle Hailey has made a video of it available…
In this blog post, I will describe how to upgrade from Oracle Enterprise Manager Cloud Control 12.1.0.3 to OEM 12.1.0.4.0. I have already described the main new features of Cloud Control 12.1.0.4 version in an earlier post (Oracle OEM Cloud Control 12.1.0.4 – the new features). The first pre-requisite is to apply the patch 11061801 on the repository database in…
By Franck Pachot . A thread on OTN Forum about Exadata came to the following question: “But how can I monitor if it is effectively used or not?”. This is a common question. There are 3 exclusive features coming with Exadata, and instance statistics can show their usage. Even better: two of them can even be checked on your current (non-Exadata)…
The new Oracle OEM Cloud Control 12.1.0.4 release migration makes it necessary for the DBA to migrate the old agent version to 12.1.0.4. If your infrastructure has a huge number of agents and if you want to apply the agent patches to the upgraded agents, this might be a very time-consuming job. However, there is a way to realize the…
This document describes the main new features of Cloud Control 12.1.0.4. A lot of new features are coming with the 12.1.0.4 version I will describe the most important ones, but you can also refer to this Oracle documen: http://docs.oracle.com/cd/E24628_01/doc.121/e25353/whats_new.htm#CEGFFGBI New management services repository page There is a new management services repository page providing details about the management repository: In the…
