SYSDBA is powerful. You should use it only when you need to. And you should audit what is done when connected SYSDBA. This is achieved by AUDIT_SYS_OPERATION. But do you have an idea how much audit log will be generated? Note that in 12c, AUDIT_SYS_OPERATION=true is the default.
All posts by Franck Pachot
When Oracle Multitenant came out in 12c, with pluggable databases, it was easy to draw them as USB sticks that you can plug and unplug to/from your Container Database (CDB). I don’t like this because it gives the false idea that an unplugged database is detached from the container.
The previous post partly answered to the original question (why an object link to V$SESSION is refreshed only every 30 seconds): recursive queries on shared=object views. Now let’s see what is different with fixed tables.
I had a comment on object links internals when creating a sharing=object view on GV$SESSION. Before posting about this specific case, I realized that I’ve never explained how a query on an object link is run on the CDB$ROOT container.
Did you know that when you set isolation level to SERIALIZABLE, it is not serializable but SNAPSHOT? This isolation levels is lower than serializable. I’ve never thought about it until I read Markus Winand slides about transactions. I recommend every developer or DBA to read those slides. This post is there to illustrate write skew in Oracle.
The Exadata X5 can be installed Bare Metal or Virtualized. The latter one, Oracle VM allows to create multiple clusters on one machine, is more complex for installation and for storage capacity planning. But it allows a small flexibility on options licencing. Those are the real challenges behind the choice. However, when we talk about virtualization, most of questions are about the overhead. Last week, we did some tests on same machine with different configuration,…
In a previous post about enabling large page on Windows Server, I explained that it’s possible to use large pages with Automatic Memory Management (AMM, where sizing if SGA and PGA is automatic with MEMORY_TARGET setting) but possible does not mean that it is recommended. We feel that it’s not a good idea, but are there reasons for it or it’s just our linux backgroud that brings this opinion?
The new ODA X-6 has been announced last month with two smaller configurations and smaller prices: 2S and 2M. Small, but high performance configuration: all SSD, and I/O transfer optimized for Flash with PCIe bus and NVMe protocol. Let’s see how it keeps up with an high OLTP workload. Thanks to Arrow Oracle Authorized Solution Center to let us evaluate performance on their ODA.