Interesting observation about standby redo logs in Data Guard

Some of you might have followed the discussion around the number of standby redo logs on twitter, but since 140 characters are woefully short for the complete story here’s the writeup that prompted the question. This is a test with 12.1.0.2 on virtualised Linux, repeated on a proper platform with physical hardware.

First of all here’s my setup. I have a dbca-based database (CDB, but doesn’t matter) that features 3 groups for (more...)

SystemTap into Oracle for Fun and Profit

Topic: This post is about using SystemTap for investigating and troubleshooting Oracle RDBMS. In particular you will learn how to probe Oracle processes and their userspace functions. These techniques aim to be useful as well as fun to learn for those keen into peeking under the hood of the technology and improve their effectiveness in troubleshooting and performance investigations.


Introduction


Userspace probing is a very powerful technique that can be used to complement the available (more...)

Building a Great Conference Agenda

We are deep into RMOUG’s abstract submissions and reviews, preparing for the following:

  • Oct. 2nd-  Close of Abstract Submissions
  • Oct. 6th-  Close of Abstract Reviews
  • Oct. 10th-  Schedule up for 2015 Training Days

With this weighing so heavily on my mind, I felt it might be a good time to put down on paper why I’m so proud of how RMOUG does it’s reviews and why this conference has such a great lineup.  This (more...)

Jonathan Lewis explains Delphix internals

Last week we had a great webinar with Jonathan Lewis as he explained his hands on experience of Delphix, how Delphix works internally and some use cases that Delphix solves for Jonathan.

Jonathan will be joining us a the Delphix booth at Oracle Open World and giving shorter version of the presentation at 10am on Monday and Tuesday and 11am on Wednesday.

Also Jonathan will be speaking at Oaktable World on both Monday 1pm and (more...)

Where is my space on Linux filesystem?

Not Often, I checked about my space after made filesystem on Linux. Today, I have made Ext4 filesystem around 460GB, I found it 437GB only. Some path should be 50GB, but it was available only 47GB.
Thank You @OracleAlchemist and @gokhanatil for good information about it.
Filesystem                   Size  Used Avail Use% Mounted on
/dev/mapper/VolGroup0-U01LV   50G   52M   47G   1% /u01

Reference  - (more...)

Extend linux partition on vmware

It was a quiet day, I worked as System Administrator and installed Oracle Linux on Virtual Machine guest. After installed Operating System, I wanted to extend disk on guest. So, I extended disk on guest. Anyway, I came back in my head what I was supposed to do on Linux then ? 
- Create new disk (and Physical Volume) and then add in Volume Group.
Checked my partition:
[root@mytest01 ~]# fdisk -l (more...)

High log file sync waits? Check log parallelism!

Log parallelism is an optimization introduced in 9.2 that reduces latch contention due to redo copy to the log buffer by enabling multiple public redo buffers (or “strands”). In many cases, however, it can cause a massive degradation of commit performance (“log file sync” wait increase). In this blog post, I will describe the mechanism, illustrate it with test results, and discuss solutions. Tests were performed on several different 11gR2 databases on Solaris servers.

Log parallelism

Log parallelism is controlled by (more...)

eSP

eSPEnkitec’s Sizing and Provisioning (eSP) is a new internal tool designed and developed with Oracle Engineered Systems in mind. Thanks to the experience and insights from Randy Johnson, Karl Arao and Frits Hoogland, what began as a pet project for some of us, over time became an actual robust APEX/PLSQL application, developed by Christoph Ruepprich and myself, and ready to debut at Oracle Open World 2014.

This posting is about eSP, what it does, and (more...)

Partitioned Clusters

In case you hadn’t noticed it, partitioning has finally reached clusters in 12c – specifically 12.1.0.2. They’re limited to hash clusters with range partitioning, but it may be enough to encourage more people to use the technology. Here’s a simple example of the syntax:


create cluster pt_hash_cluster (
        id              number(8,0),
        d_date          date,
        small_vc        varchar2(8),
        padding         varchar2(100)
)
-- single table
hashkeys 10000
hash is id
size 700
partition by range (d_date) (
        partition  (more...)

SYSAUX Growing rapidly!!! What can be done

Recently i have been working on cleaning up SYSAUX tablespace for few of clients, so thought to put down my steps which might be helpful to some of you out there. Why does SYSAUX tablespace grows much larger than expected? There could be number of potential reasons: 1. ASH data has grown too large (SM/AWR)…

Oracle Disaster Recovery with Microsoft Hyper-V Replica

There is one very interesting feature of Microsoft Hyper-V called Replica, which allows replication of Virtual Machines without shared storage. With Hyper-V Replica, one can set up Oracle Database VMs to replicate between independent nodes. This document (in german) describes the setup in more detail:

Hyper-V Replica für Oracle Database

How to Configure EM12c to NOT Use Load Balancers

This may not come up very often, but for some reason, an administrator might have to reconfigure an EM12c environment to NOT use load balancers.

This could be due to:

1.  Hardware Issue on the Load Balancers
2.  Mis-configured Load Balancers
3.  Re-allocation of Load Balancer hardware for other purposes.

Whatever the reason may be, I noted that the instructions to set up the load balancers are easy to find, but not (more...)

Oracle Open World: Oaktable speakers at Delphix booth

Screen Shot 2014-09-19 at 2.16.51 PM


Planning to attend Oracle OpenWorld this year? 

If so, stop by to visit Delphix at booth 821 and hear from Oracle industry luminaries such as Jonathan Lewis, Tim Gorman, Kyle Hailey, Ben Prusinski and the Oracle Alchemist, Steve Karam.

  • Taking Back Your Time: The Power of Virtual Databases, Jonathan Lewis
  • Virtual Data Platform: Revolutionizing Database Cloning, Kyle Hailey
  • Virtual Data for the High Performance Warehouse, Steve Karam
  • Transforming IT Infrastructure, Tim Gorman
  • Oracle E-Business Suite (more...)

Shrink Tablespace

A recent question on the OTN database forum raised the topic of returning free space in a tablespace to the operating system by rebuilding objects to fill the gaps near the start of files and leave the empty space at the ends of files so that the files could be resized downwards.

This isn’t a process that you’re likely to need frequently, but I have written a couple of notes about it, including a (more...)

Switch CentOS to Oracle Linux – centos2ol.sh

My time has used much with Linux. Some people asked to move from CentOS to Oracle Linux somehow. I used to believe it easy to do like that. Anyway, It'd better to test. 
I focused on 2 links.
https://linux.oracle.com/switch/centos/
http://docs.oracle.com/cd/E37670_01/E37355/html/ol_switch_yum.html

Oracle introduces centos2ol.sh script that can convert CentOS 5 and 6 systems to Oracle Linux. After that run "yum upgrade" again.
[root@test-centos ~]# uname -r
2.6.32-431.29. (more...)

Oracle OpenWorld 2014 – XML and JSON presentations, meetings and Hands-On Labs

Oracle OpenWorld is about to start and I am looking forward to it. This year I will be able to learn and enjoy it a...

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Larry Ellison Stepping Down as Chief of Oracle

Larry Ellison, CEO of Oracle is finally stepping down! He’s not leaving Oracle but as part of succession planning will be moving into the Executive Chairman role. He is one of the co-founders of Oracle and started the enterprise in 1977. The CEO responsibility will be shared between Mark V. Hurd and Safra A. Catz. […]

The post Larry Ellison Stepping Down as Chief of Oracle appeared first on VitalSoftTech.

Oracle Open World Schedule

I will be in San Francisco a little early this year and as I’m not longer an ACE Director, it’s to attend the IOUC, (International Oracle User Conference) at Redwood Shores on Sept. 25th and 26th.  I’ll be representing RMOUG for the two day event that has representatives from user groups from all over the world.  Our lovely host, Mary Lou Dopart and her team, will ensure we have another great (more...)

Private Cloud and Lifecycle Management with EM12c at OOW14

Yet again the monster that is Oracle Open World is about to take over San Francisco. I won’t be making it this year, but considering we had something like 60,000 attendees last year I’d hate to see what the numbers are gonna be this year! :)

To try and make it a little easier for you to find all the Private Cloud and Lifecycle Management with EM12c material, here are the ones I know about. If (more...)

Datafile space reclaimable report.

These script will help you find the space reclaimable in your datafiles, it finds the High Water Mark of all your datafiles (the minimum size) and then report the following information: Datafile Size Datafile HWM Percentage of space reclaimable Command to resize the datafile Total space reclaimable in your datafiles Percentage of space reclaimable in your datafiles Find space reclaimable [...]

The post Datafile space reclaimable report. appeared first on Oracle DBA Scripts and Articles (Montreal).