RDA, or the Remote Diagnostics Agent, has been around for a little while. Over the time, and with the growing number of Oracle’s acquisitions it has become, shall we say, a little more difficult to handle. It appears to me as if every one of them will have its diagnostics handled by RDA making it hard to focus on something specific, like for example the database.
I won’t go into very detail of the Remote (more...)
Some time ago I wrote a post about using OSWatcher for system analysis. Neil Chandler (@ChandlerDBA) rightfully pointed out that although OSWatcher was cool, 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.
I guess it depends on what you want to do-I still think that OSWatcher is a good starting point and enough for most problems on single (more...)
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. After all, if the gatekeeper to your database environment fails, you are effectively closed for business. One option would (more...)
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.
Assume for a moment that you upgraded Oracle binaries from 22.214.171.124.5 to 126.96.36.199.160419. (more...)
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 (which I love) help you a lot. Not only do your DBA scripts work reliably everywhere, but the error condition (more...)
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 why not automate the process? For quite some time DBCA, or the Database Creation Assistant offers you the option (more...)
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 start it. Most users add it to the startup mechanism their O/S uses- SysV init, upstart, or systemd for example (more...)
This is just another short post about one of the little things worth knowing. Assume you are on 188.8.131.52 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 be exhausted. Setting parallel_degree_limit of course only has an effect if you set parallel_degree_policy to limited, auto (more...)
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 to a clone of a database when I roll the master copy forward?”
In the first part of the (more...)
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 to me at home so I had to revert to the simulator, hoping that it represents the real appliance accurately.