Monthly Archives: July 2014

Disabling Oracle’s new Database In-Memory option, or perhaps not!

You may already be aware of there now being a number of online articles and blog posts concerning issues around the potential for accidental enabling of the new Oracle Database In-Memory Option; with pricing understood to be the same as for Oracle’s Real Application Clusters and Oracle’s legendary tough stance on license audit findings, it is not difficult to see why this has got the attention it has.

The initial InformationWeek Report: Oracle Patch Turns On $23,000 Upgrade, was followed on 28th May by CBR Online reporting Oracle Denies Its £14,000 In-Memory Option Activates By Default and then Oracle hits back at ex-employee’s claims over in-memory database option.

My years in the IT industry certainly mean it is no surprise to me that my colleague at EMC, Kevin Closson, having raised awareness of the issues on his now 4-part personal blog, nevertheless I am disappointed that he has been subjected to criticism and occasional ridicule from so-called IT industry experts and apparently from some of his former colleagues at Oracle Corporation.

In her blog post Getting started with Oracle Database In-Memory Part I, Maria Colgan, Oracle’s Product Manager for Oracle Database In-Memory, has attempted to address the issues raised without mentioning them directly, by starting with the intention to answer the question “how and when is Database In-Memory installed and enabled”.

My initial response was enthusiastic, I still believe Maria has made a positive contribution to the discussion, I commented as such on her blog post, as I believed she had provided clarity on how to avoid accidentally enabling the new Oracle Database In-Memory Option and as a result avoid exposure to potential license audit problems. However, it has become clear after my own testing that Maria and her colleagues need to look at this again.

This is due to what I have described as “no rows selected” == “DOUBT” – the SQL SELECT statement used to enquire of the feature usage in the Oracle Database makes use of a dba_feature_usage_statistics view that joins 3 WRI tables and in my tests one of these tables (WRI$_DBU_FEATURE_USAGE) is empty!

Screen Shot 2014-07-30 at 02.37.30

After much consternation and multiple install and test runs, I concluded that in my initial tests the WRI$_DBU_FEATURE_USAGE table is unpopulated when performed in the CDB$ROOT database and certainly results in the “no rows selected” output (Ed. happy to be corrected here)

However, when the tests are performed using the orclpdb PDB, installed as part of the Typical Installation of the Oracle Database 12c software, I see output similar to that provided by Kevin Closson. I say similar, as you can see below I am yet to reproduce his output that has resulted in such controversy!

Screen Shot 2014-07-30 at 02.41.47

Clearly, there is something different about our tests, perhaps some sqlplus flags or other settings. What we need to do is share the exact configuration and commands and get to the bottom of this in a mutually agreeable and respectful manner, let’s see what we can do.




Will the All-Flash Array Market go away? - The Home of Storage Switzerland

Recently HDS’s Hu Yoshida wrote in his blog that he thinks the all-flash array market will go away. I very often find myself agreeing with Hu, he’s a sharp guy and I respect his point of view. As an example, later in that same blog he predicts that file sync and share will become a component of object storage; I agree with that. But as for the disappearance of the all-flash array market I have to disagree. Not only will the all-flash array market not go away but I believe that over the next 5-6 years it will become the only way that production data is stored.

All-Flash Now

To arrive at this conclusion we have essentially three trends to follow here; what is happening now, what will happen in the near future (next year) and what will happen in the more distant future (5 years +). Right now IT…

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EMC XtremIO – The Full-Featured All-Flash Array. Interested In Oracle Performance? See The Whitepaper.

Kevin Closson's Blog: Platforms, Databases and Storage

I recently submitted a manuscript to the EMC XtremIO Business Unit covering some compelling lab results from testing I concluded earlier this year. I hope you’ll find the paper interesting.

There is a link to the full paper at the bottom of this block post. I’ve pasted the executive summary here:

Executive Summary

Physical I/O patterns generated by Oracle Database workloads are well understood. The predictable nature of these I/O characteristics have historically enabled platform vendors to implement widely varying I/O acceleration technologies including prefetching, coalescing transfers, tiering, caching and even I/O elimination. However, the key presumption central to all of these acceleration technologies is that there is an identifiable active data set. While it is true that Oracle Database workloads generally settle on an active data set, the active data set for a workload is seldom static—it tends to move based on easily understood factors such as data aging…

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XtremIO’s In-Memory Metadata Architecture – Fact and Fiction

Itzikr's Blog

During our launch last week we discussed the amazing benefits of XtremIO’s In-Memory Metadata architecture. Some have seen fit to FUD this approach as risky – what happens to valuable metadata if a controller (or power) fails and memory contents are lost? Believe it or not, we did think about these things when designing XtremIO.So let us clear the air – in-memory metadata is a run-time capability of the array that significantly boosts performance. Metadata is not exclusively kept in memory. It is also journaled, protected, and hardened to SSD and can tolerate any failure event in the array. We couldn’t cover every detail of this during a one-hour launch event, so here’s what we didn’t have time to say last week.

Searching for Facts vs. Fiction - Magnifying Glass

To set the foundation, let’s briefly review the concept of metadata. In the context of storage systems, metadata is simply useful internal information managed by the array…

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XtremIO – Redefining Snapshots

Itzikr's Blog

A guest post by Tamir Segal, Senior PM

Snapshots is a technology that enables creating copies of volumes. XtremIO has developed a snapshot embedment that provides the ability to create space efficient snapshots that are managed as standard volumes in the cluster and have the same performance capabilities and data services as production volumes. In this post I provide a general explanation on legacy snapshot implementation, and explain what makes an XtremIO snapshot different.

Some Background

Legacy implementation of snapshot was based on technology called Copy-On-First-Write. The idea of Copy-On-First-Write is that once a snapshot is created, a new storage pool is defined in the system; every write to the production volume triggers a data movement operation to the snapshot pool:

· A new write is received by the system on LBA X

· The system reads the original data on LBA X from the production volume

· The system…

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Data Science as a Service: Driving Agility and Innovation to the ITaaS Model

EMC IT Proven

By Dr. Alon Grubshtein, Principal Data Scientist — EMC IT

This is a great time to be a data scientist –a bit like rock stars with all the fans always trying to catch some private time with us. While there’s is no clear definition of what a data scientist is (see related blog or view diagram of DS skillset) our take on this role is quite simple:

  1. Work with stakeholders to elevate high impact business related questions
  2. Find the means to answer these questions

This blog aggregates our collective experiences as members of EMC’s Corporate IT Data-Science-as-a-Service (DSaaS) team. Our team has been active since 2012, providing Data Science (DS) services to different business units as part of EMC IT’s transformation to an agile and innovative IT-as-a-Service model.

Although we aimed for a technical blog, we thought that the first post should provide a broader context to the…

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Fun with Linux UDEV and ASM: Using UDEV to create ASM disk volumes

Dirty Cache

floppy-disksBecause of the many discussions and confusion around the topic of partitioning, disk alignment and it’s brother issue, ASM disk management, hereby an explanation on how to use UDEV, and as an extra, I present a tool that manages some of this stuff for you.

The questions could be summarized as follows:

  • When do we have issues with disk alignment and why?
  • What methods are available to set alignment correctly and to verify?
  • Should we use ASMlib or are there alternatives? If so, which ones and how to manage those?

I’ve written 2 blogposts on the matter of alignment so I am not going to repeat myself on the details. The only thing you need to remember is that classic “MS-DOS” disk partitioning, by default, starts the first partition on the disk at the wrong offset (wrong in terms of optimal performance). The old partitioning scheme was invented when physical…

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