from$_subquery$_NNN

Uncategorized
| May 12, 2020

This is a reference note for a question that came up as a comment on a lengthy note I wrote about reading execution plans.

How do you interpret something like: from$_subquery$_001@SEL$1 in the Query Block Name / Object Alias section of an execution plan.

The simple answer is that if you’ve got an inline view in the FROM clause of a query and you haven’t given the inline view an alias the optimizer will have (more...)

Testing RMAN Restore Validate From Tape

Uncategorized
| May 12, 2020

Short and simple method to validate backup.

oracle@hawk:/home/oracle$ rman checksyntax @ restore_validate_idpa_ddbea.rman

Recovery Manager: Release 11.2.0.4.0 - Production on Tue May 12 07:24:57 2020

Copyright (c) 1982, 2011, Oracle and/or its affiliates.  All rights reserved.

RMAN> set echo on
2> connect target;
3> show all;
4> list backup summary;
5> report schema;
6> run {
7> allocate channel ch1 type 'SBT_TAPE' parms 'SBT_LIBRARY=/opt/libddboostora.so,SBT_PARMS=(CONFIG_FILE=/opt/idpa_ddbea.config)';
8> allocate channel ch2 type  (more...)

Arbitrary length addition and subtraction

Uncategorized
| May 11, 2020

This one just for fun today. An AskTOM question came in about arbitrary length arithmetic because “NUMBER(38) was not enough”. After some back-and-forth discussions it turned out that the business need under the requirement was managing bit strings. The implementation was currently converting the bits to decimals, hence the need for potentially very large number handling.

The problem was ultimately tackled with using RAW datatypes and holding the bits as raw strings, but I thought (more...)

Oracle 19c Automatic Indexing: Dropping Automatic Indexes (Fall Dog Bombs The Moon)

Uncategorized
| May 11, 2020
Julian Dontcheff recently wrote a nice article on the new Automatic Index Optimization feature available in the upcoming Oracle Database 20c release (I’ll of course blog about this new 20c feature in the near future). Within the article, Julian mentioned a clever method of how to effectively drop Automatic Indexes that I thought would be […]

Service Battery warning on macOS

Uncategorized
| May 11, 2020

Scene: INT. LATE NIGHT.
NATALKA is typing on a MACBOOK AIR.
Suddenly, the screen goes dark. Silence. The MACBOOK AIR has shut down with no warning.

Once upon a time, my laptop was well-behaved. It warned me politely when it was nearly out of power and shutdown was imminent.

Low Battery. Your Mac will sleep soon unless plugged into a power outlet.
Image ganked from someone who still gets these warnings.

But sometime in the last six years, my MacBook lost the ability to keep track of its (more...)

Exadata Virtualized DB node restore

Uncategorized
| May 11, 2020

There are two common scenarios when we may need this:

  • An existing DB node has crashed and is unrecoverable (due to some failure and non-availability of any backups. Though some of the things may need to be done even if the backups were available).
  • We have an existing Exadata rack that is virtualized. Now there is a new DB node and the existing clusters need to be extended to include the VMs on this new (more...)

Oracle Linux 8 (OL8) : Updates – UEK6, Podman, Database 19c Certification

Uncategorized
| May 11, 2020

Last week I had a quick email exchange with Simon Coter from Oracle about a few things related to Oracle Linux 8. I’ve been a little out of the loop over the last few weeks because of some important world event or another, so I had a bit of catching up to do.

UEK6 Went GA

UEK6 had been in preview for a while. In March it went GA, and I managed to miss that (more...)

Silent installation: Oracle Restart 19c, ASM Filter Driver, UEK 5 edition

Uncategorized
| May 11, 2020

As promised in an earlier post here are my notes about installing Oracle Restart with ASM Filter Driver (ASMFD) 19c on Oracle Linux 7 using UEK 5.

Since the approach you are about to read isn’t explicitly covered in the documentation I suggest you ask Oracle Support whether it is supported before using this outside a playground/lab environment.

I also forgot about this post waiting to be published in my drafts folder, it should have (more...)

Video : NTILE : Problem Solving using Analytic Functions

Uncategorized
| May 10, 2020

In today’s video we work through some examples of using the NTILE analytic function to solve some specific problems.

The video is based on the following article.

You might find these useful also.

The star of today’s video is Alex Nuijten‘s daughter, but I thought I better include him also or he would get jealous. 🙂

Cheers

Tim…


(more...)

Migration methods to Autonomous Database (ADB) – Part I (Data Pump)

Uncategorized
| May 10, 2020
In this part of on-premise Oracle database migration to ADB series, we will focus on set of tools to migrate your on-prime database to Autonomies database (ADB). We will briefly discuss about various migration solutions offered by Oracle and walk through data pumps migration pre-requisites and procedure.

Database cloud migration requires a good amount of knowledge about various methods offered by Oracle and the best solution that suits your business need. The best place to (more...)

nohup vs screen

Uncategorized
| May 10, 2020

While I have played a little with screen , my preference is nohup since the output from screen is so ugly.

With that being said, it would be nice for application designs to be resumable, e.g. Shocking opatchauto resume works after auto-logout

There were discussions about running many SQLs where each SQL is run manually, check for error before running the next SQL; hence, screen was used.

Why not trap for error and (more...)

Oracle EUS authentication with LSA activated on AD

Uncategorized
| May 9, 2020
Are there to many abbrevations in a posts title possible? If you think so, you might see this post a good example. 


The setting I'm talking about is an Oracle Universal Directory (OUD) which works as a proxy between Oracle databases and Active Directory (AD) where the users are managed. Unfortunately it stopped working. Even when a user changed the password in AD, it could not log in with this (more...)

Advanced Oracle SQL Tuning Training

Uncategorized
| May 8, 2020
When I delivered a previous version of this class last, it was year 2013 and the latest Oracle version was 11.2. Since plenty of people have asked if I ever do this training again - and now that Oracle 18c is out with a lot of new (and adaptive) stuff added since version 11, I’ve decided to update the material and run it again as an online training class :)

Practical Linux Performance and Application Troubleshooting Training

Uncategorized
| May 8, 2020
Training overview The emphasis of this class is on practical application troubleshooting and Linux OS performance tuning techniques. We’ll be using scripts and tools that you can use on any Linux machine whenever a problem happens, without having to first install a complex layer of monitoring tools. At the same time, we will go way beyond what the classic sysadmin tools (like vmstat, iostat, top) have to offer. We will use a process/thread-level sampling approach (more...)

Confirmation

Uncategorized
| May 8, 2020
Success! Thanks for signing up for my class! You will receive an email with the payment receipt from Paypal that confirms your attendance. If you don’t see this email, please check your spam folder. In case of any questions, please email: seminars@poderc.com I will send out the slides, scripts and webinar joining instructions on the week before the class starts. There’s more info and instructions on how to prepare for the online classes on (more...)

Hacking Session: Oracle SQL Monitoring – Understanding the Execution Timeline column and CPU usage

Uncategorized
| May 8, 2020
I will run another hacking session that has been in my mind for a while. It will be a pretty narrow deep-dive into one of the SQL Monitoring report’s columns that is not well explained: Oracle SQL Monitoring - Understanding the Execution Timeline column In this hacking session, I will explain how to read the “Execution Timeline” column in the SQL Monitoring reports. There are some gotchas and things that look like inconsistencies to be (more...)

Oracle 20c DBCA

Uncategorized
| May 7, 2020

As you probably know, Oracle 20c is available only as a preview on the cloud. If you’d like to create a new server on Oracle Cloud with 20c, here is a post with the instructions.

However, I thought of a way to still check the new dbca and it’s quite simple. Once you have a running server, it seems that the DB VM already contains tigervnc. So all you need to do is to start (more...)

Cloud Vanity: A Weekly Carnival of AWS, GCP and Azure – Edition 1

Uncategorized
| May 7, 2020
This is the first edition of this weekly collection about what is happening in the rapidly evolving cloud sphere. This will mainly focus on news, blogs, articles, tidbits, and views from AWS, Azure and GCP but will also include other Cloud providers from time to time. Enjoy Reading!!!




AWS:

Amazon Relational Database Service (RDS) for SQL Server now supports distributed transactions using Microsoft Distributed Transaction Coordinator (MSDTC). With MSDTC, you can run distributed (more...)

OEDA Virtualized Cluster Discovery With SSH Keys

Uncategorized
| May 7, 2020

As part of the Oracle Exadata Deployment Assistant (“OEDA”), Oracle includes a command line utility to read and modify the XML files used for deployment of an Exadata cluster.  Typical use cases are to install additional Oracle database versions, or to create multiple databases before deployment.  There are several additional features included for virtualized clusters, particularly the ability to simplify upgrading Grid Infrastructure.

In many cases, the original XML used for the deployment (more...)

Build an HVR Hub without underlying database

Uncategorized
| May 7, 2020

In recent years, the data integration/replication space has stared to become crowded.  Products like Oracle GoldenGate have become stables inside of organizations, but companies like HVR are chipping away at that marketshare.  Since I left Oracle, I’ve been evaluating and looking at some of these data integration/replication tools and I like HVR.  HVR provides some […]

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