Tag Archives: MAA

ZDLRA, Virtual Private Catalog User – VPC

The Virtual Private Catalog (VPC) user is a key piece for a good ZDLRA architecture design. The detail is not how to create it, but how to correctly integrate it in your design, and this is more important if you have replicated ZDLRA or using Real-Time redo transport.

Here I will show and discuss VPC implications for your architecture design when deploying ZDLRA. Even for a complete and new implementation (together with database) or adding ZDLRA at your already running environment. All points here try to show some perspectives and key points that can help you to correct use and define VPC’s.

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ZDLRA, Webinar

On 18/Dec/2019 I presented a webinar about ZDLRA: Understanding ZDLRA. This was done through the Luxembourg Oracle User Group (LUXOUG).

In this webinar, I covered some details about what it is, and some features that are part of ZDLRA. Besides that, I showed internals details about how it stores and indexes the backups. 

If you lose it, you can watch now. It is free. Just check these two links:

You can download the presentation here too: Understanding ZDLRA.

Fell free to follow my website and check more details for ZDLRA and other posts about EXADATA, MAA, and Oracle.

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ZDLRA, Real-Time Redo

Real-time redo transport is the feature that allows you to reduce to zero the RPO (Recovery Point Objective) for your database. Check how to configure real-time redo, the steps, parameters, and other details that need to be modified to enable it.

The idea behind real-time redo transport it is easy, basically the ZDLRA it is a remote destination for your redo log buffers/archivelogs of your database. It is really, really, similar to what occurs for data guard configurations (but here you don’t need to set all datafiles as an example). It is not the same too because ZDLRA can detect if the database stops/crash and will generate the archivelog (at ZDLRA side) with all the received redo and this can be used to restore to, at least zero/sub-seconds, of data loss.

Using real-time redo it is the only way to reach RPO zero. With other features of ZDLRA, you can have a better backup window time (but just that) using incremental backups. Just using real-time redo you reach zero RPO and this impacts directly how to configure for MAA compliance. There are a lot of options and level of protection for MAA that you can check at “Maximum Availability Architecture (MAA) – On-Premises HA Reference Architectures 2019”, “Maximum Availability Architecture Best Practices for Oracle Cloud”, “Oracle MAA Reference Architectures”, “Maximum Availability Architecture – Best Practices for Oracle Database 19c”.

This post starts from one environment that you already enrolled in the database at ZDLRA. I already wrote about how to do that, you can check here in my previous post. This is the first post about real-time redo, here you will see how to configure and verify it is working.

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Observer, More Than One

Recently I made a post about a little issue that I got with Oracle Data Guard. In that scenario, because of outage in the standby datacenter, healthy primary database shutdown with error “ORA-16830: primary isolated…”. Just to remember that the database was running with Maximum Availability, Fail-Start Failover enabled and (the most important detail) the Observer was running in the standby datacenter too.

The point from my previous post tried to show that does not exists one doc that provides full details about “pros” and “cons” where put your observer. Whatever the place, on the primary datacenter or in standby, it has little details to check. Even the best (ideal) scenario, with a third datacenter, can be tough to sustain.

Here I will try to show one option that can help you and improve the reliability of your MAA/DG environment. At least, you will have more options to decide how to protect your database. Bellow, I show some details about how to configure and use multiple observers, but if you want to jump and see a little concern you can directly to the end of the post.

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