Martins Blog

Powered by
WordPress

  • RAC 12c enhancements: adding an additional SCAN-part 4

    This is going to be the last part of this series, however long it might end up being in the end. In the previous articles you read how to create a physical standby database from a RAC One database. Networks (refresher) To make it easier to follow without going back to the previous articles, here…

  • Mysterious new Oracle compression type

    As part of our research for our joint presentation at OGH.nl and E4 my colleague Frits Hoogland made an interesting discovery. He verified the compression format for updated rows previously compressed using Hybrid Columnar Compression (HCC). In that particular example we researched HCC data on Exadata storage. As you may know, reading HCC data in…

  • RAC 12c enhancements: adding an additional SCAN-part 3

    Travel time can be writing time and while sitting in the departure lounge waiting for my flight I use the opportunity to add part 3 of the series. In the previous two parts you could read how to add a second SCAN and the necessary infrastructure to the cluster. Now it is time to create…

  • RAC 12c enhancements: adding an additional SCAN-part 2

    In the first part of this article you could read how to add an additional network resource, additional VIPs and SCAN to an 12.1.0.1.2 cluster. In this part I hope to show you the next steps such as adding the SCAN listeners and other resources. New SCAN listener With the second SCAN added it is…

  • RAC 12c enhancements: adding an additional SCAN-part 1

    Based on customer request Oracle has added the functionality to add a second SCAN, completely independent of the SCAN defined/created during the cluster creation. Why would you want to use this feature? A few reasons that spring to mind are: Consolidation: customers insist on using a different network Separate network for Data Guard traffic To…

  • How important is a Disaster Recovery site for you?

    I regularly read threads on the oracle-l mailing list, and occasionally feel very tempted to reply to one. Just recently I saw one that I liked a lot. It is specifically about using an Oracle Database Appliance (ODA) as a Disaster Recovery (DR) solution for an Exadata system. The Exadata configuration was not specified, I…

  • Duplicate from the standby instead from the primary in 12c

    This post is related to 12c and an active database duplication for a standby I did in my lab environment. I’d say although I first encountered it on 12c there is a chance you run into a similar situation with earlier releases too. I would normally use ASM for all my databases to make my…

  • Recovering a standby over the network in 12c

    Another one of the cool but underrated features in 12c is the possibility to recover a physical standby over the network with one line in RMAN. Why do you need to perform this activity? Assume someone really clever created a segment “nologging” and the database was not in force logging mode. This operation cannot be…

  • Interesting GNS anomaly in 12.1.0.1.2 RAC

    I was encountering an interesting anomaly with my 12.1.0.1.2 RAC cluster based on Grid Naming System. I have written about the setup here. No need to get back to the post-instead let me give you some background if you are not familiar with the Grid Naming System in RAC. Most RAC installations use a Domain…

  • Runtime Load Balancing Advisory in RAC 12c-addendum

    A reader asked an interesting question yesterday with regards to the previous post on the subject: where did you get your service metrics from when you queried v$servicemetric-PDB or CDB$ROOT? I queried the PDB, but this morning repeated the test to make sure the results are consistent, and they are. This is definitely something you’d…