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Autonomous

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.

image

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:

ATP vs ADW – the Autonomous Database lockdown profiles

By Franck Pachot

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The Oracle database has always distinguished two types of workloads: transactional (OLTP) and datawarehouse (VLDB, DWH, DSS, BI, analytics). There is the same idea in the managed Oracle Cloud with two autonomous database services.

To show how this is old, here is how they were defined in the Oracle7 Tuning Book:

CaptureOLTPvsDSS

The definition has not changed a lot. But the technology behind DSS/DWH has improved. Now, with In-Memory Column Store, Smart Scan, Result Cache we can even see that indexes, materialized views, star transformation, hints,.. are disabled in the Autonomous Datawarehouse cloud service.

ADWC – System and session settings (DWCS lockdown profile)

By Franck Pachot

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The Autonomous Data Warehouse Cloud service is a PaaS managed service where we have a PDB and an ADMIN user which has most of the system privileges. For example, we have the privilege to change initialization parameters:
SQL> select * from dba_sys_privs where grantee=user and privilege like 'ALTER S%';
 
GRANTEE PRIVILEGE ADMIN_OPTION COMMON INHERITED
------- --------- ------------ ------ ---------
ADMIN ALTER SESSION YES NO NO
ADMIN ALTER SYSTEM YES NO NO

ADWC – connect from your premises

By Franck Pachot

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In the previous post about the Autonomous Data Warehouse Service, I’ve run queries though the Machine Learning Notebooks. But you obviously want to connect to it from your premises, with SQL*Net.

ADWC – the hidden gem: Zepplin Notebook

By Franck Pachot

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IMG_5339
In the previous blog posts I explained how to create, and stop/start the Autonomous Data Warehouse Cloud service. And I didn’t show yet how to connect to it. It is easy, from sqlplus or SQL Developer, or SQLcl.

But there’s something more exciting to run some SQL queries: the Oracle Machine Learning Notebooks based on Apache Zepplin. At first, I didn’t realize why the administration menu entry to create users in the ADWC service was named ‘Manage Oracle ML Users’, and didn’t realize that the ‘Autonomous Data Warehouse Cloud’ header was replaced by ‘Machine Learning’.