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Autonomous

A Serverless Standby Database called Oracle Autonomous Data Guard

By Franck Pachot

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Announced by Larry Ellison last week, here it is: the Autonomous Data Guard. You can try it, unfortunately not on the Free Tier.
First you create an Autonomous Database (ATP or ADW) and then you enable Autonomous Data Guard.

Upgrading…Its Time!

Gough Whitlam was an Australian politician who rose to power in the 1970s with the campaign slogan “It’s Time!”. Politics aside, it loosely ran on the premise that not to have the occasional dramatic change ultimately leads to stagnation in social and economic progress.

428px-Gough_Whitlam_1973

Oracle Autonomous Linux: cron’d ksplice and yum updates

By Franck Pachot

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Oracle Enterprise Linux (OEL) is a Linux distribution which is binary compatible with Red Hat Enterprise Linux (RHEL). However, unlike RHEL, OEL is open source, free to download, free to use, free to distribute, free to update and gets free bug fixes. And there are more frequent updates in OEL than in CentOS, the free base of RHEL. You can pay a subscription for additional support and features (like Ksplice or Dtrace) in OEL. It can run the same kernel as RHEL but also provides, still for free, the ‘unbreakable kernel’ (UEK) which is still compatible with RHEL but enhanced with optimizations, recommended especially when running Oracle products.

Consumer Group Mapping Rules Use Pattern Matching from 12.1

I recently noticed a small, but I think significant, change in the way consumer group mapping rules behave from Oracle 11.2.04.  Session attributes can be matched to resource groups using LIKE expressions and simple regular expressions specified in the matching rules, though only for certain attributes.
(Updated 12.11.2019) I am grateful to Mikhail Velikikh for his comment.  It depends on which version of Oracle's documentation for 11.2 you read.  Pattern matching does work in 11.2.0.4 for the attributes listed in the 12.1 documentation. My testing indicates that pattern matching does not happen in 11.2.0.3.
You cannot pattern match the SERVICE_NAME in 11.2.  The attribute value is validated against the list of valid services.

Autonomous Transaction Processing – your slice of the pie

I grabbed the following screen shot from a slide deck I’ve been giving about Autonomous Transaction Processing (ATP). It shows the services that are made available to you once you create your database. At first glance, it looks like we have a simple tier, where the lower in the tier you are, the smaller the slice of the database resource “pie” you get.

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Oracle ATP: MEDIUM and HIGH services are not for OLTP

The Autonomous Transaction Processing services HIGH and MEDIUM are forcing Parallel DML, which can lock the tables in eXclusive mode.

This may seem obvious that the TP and TPURGENT are for OLTP. But when you know that the service names are associated with Resource Manager consumer groups, you may think that high priority use cases should run on the HIGH service. However those LOW, MEDIUM, HIGH services were probably named when ADW was the only Autonomous Database and it is not directly obvious that they are there for reporting only, or maybe for some batch operations.

A Brief Look Inside Oracle's Autonomous Data Warehouse Cloud

This post is part of a series that discusses some common issues in data warehouses.
There is lots of documentation for Autonomous Data Warehouse Cloud (ADWC), in which I found this bold claim:

How Not to Build A(n Autonomous) Data Warehouse

My day job involves investigating and resolving performance problems, so I get to see a lot of bad stuff.  Often, these problems have their roots in poor design.  It is not surprising. but is nonetheless disappointing, that when I point this out I am told that the system is either delivered this way by the vendor, or it has already been built and it is too late to change.
In the last couple of years, I have worked on several data warehouse applications that have provided the inspiration for a new presentation that I am giving at the DOAG and UKOUG conferences this year.
The presentation and this series of related blogs have several objectives:

Start/Stop your Autonomous Databases

The ATLAS experiment in LEGO®

Here are two blog posts on the Databases at CERN blog: