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  • OSWatcher integration in Trace File Analyzer (TFA)

    Some time ago I wrote a post about using OSWatcher for system analysis. Neil Chandler (@ChandlerDBA) rightfully pointed out that although OSWatcher on its own was all right, Tracefile Analyzer(TFA) was the way to go. TFA can include OSWatcher, but more importantly it adds a lot of value over and above what OSWatcher does. Up…

  • Preventing a SPOF with CMAN 12c

    I have already written about the use of Connection Manager 11.2 to govern access to a database. While researching this piece I have updated the original post so that it’s relevant for 12c as well. Although the idea of using Connection Manager is tempting, the obvious first question is about high availability of the process, you…

  • Tales from the field: potential reasons for PDB plug-in violations part 2

    In the first part of this little series I explained how a missing (default) tablespace in a PDB can have an impact when opening it. In this instalment I’ll add another common cause for PDBs not opening in read-write mode: different patch levels between the PDB to be plugged in and the CDB. Scenario Assume…

  • Tales from the field: potential reasons for PDB plug-in violations part 1

    Container Databases have been an area that I have researched intensively over the past years. With this post (and hopefully some others that follow) I would like to demonstrate some of the new situations the DBA might be confronted with. Please don’t use this post to give the new 12c architecture a hard time: standardised deployments…

  • Automatic Deployment of CDBs with non-default database options in 12.1.0.2

    I have written about the importance of automation in previous posts, and this one is following the same line. This time I wanted to test and document my experience with “golden database templates”. Wy? Because most DBAs will appreciate that there are more interesting things to do than to run “create database” scripts all day, so…

  • Using OSWatcher for system diagnostics

    OSWatcher is a superb tool that gathers information about your system in the background and stores it in an (optionally compressed) archive directory. As an Oracle DBA I like the analogy with statspack: you make the tool available on the host in a location with – very important – enough available disk space and then…

  • Little things worth knowing: auto-DOP or hint-which one takes precedence?

    This is just another short post about one of the little things worth knowing. Assume you are on 12.1.0.2 for example and you want to know if parallel_degree_limit reliably keeps the degree of parallelism at bay, for all sessions and queries across the board. After all, every machine has finite CPU (and other) resources that shouldn’t…

  • Experimenting with the ZFSSA’s snapshot capability using the simulator part 2

    In my last post I wrote down some notes about my experience while experimenting with the ZFSSA simulator. A simulator is a great way to get familiar with the user interface and general usability of a product. What I wanted to find out using the ZFSSA simulator was the answer to the question: “what happens…

  • Experimenting with the ZFSSA’s snapshot capability using the simulator

    Recently I have been asked how the Copy-on-Write cloning works on the ZFS Storage Appliance. More specifically, the question was about the “master” copy: did it have to be static or could it be rolled forward? What better than a test to work out how it works. Unfortunately I don’t have an actual system available…

  • Trouble with multiple SCAN listeners in 12c Release 1

    UPDATE 28-JUL-2016: the problem – as stated by Anil in the comments section – seems to be fixed. I applied the Proactive Bundle Patch 23273686 and OJVM patch 23177536 to the Grid and RDBMS home. After a successful execution of datapatch the errors in the CRSD agent log I reported in this post went away, and I…