Permissions for both HDFS and local fileSystem paths

| Jul 18, 2014

Hi All,

Permission issues is one of the key error , while setting up Hadoop Cluster, while debugging some error found below table on . It’s a good scorecard to keep handy.


Permissions for both HDFS and local fileSystem paths

The following table lists various paths on HDFS and local filesystems (on all nodes) and recommended permissions:

Filesystem Path User:Group Permissions
local hdfs:hadoop drwx——
local (more...)

Rolling upgrads using logical standby database.

Couple of weeks ago there was a Twitter discussion started by Martin Bach (@MartinDBA) about cases for logical standby implementation. A rolling upgrade was mentioned by Tim Gorman (@timothyjgormanas) as one of potential recommendations for using this rare use product. I have been involved in such project in the past and I prepared an instruction and did quite large number of rolling upgrades from 11.1 into 11.2.

There are couple of my “gotchas”

Oracle Direct NFS and Infiniband: A Less-Than-Perfect Match

Readers of an earlier post on this blog will know about my latest forays into the world of Direct NFS. Part of that means stumbling over configuration hiccups or slamming into brick walls when you find new bugs.

To quickly re-set the table, my organization purchased the Oracle ZFS Storage Appliance (ZFSSA) 7420. Oracle sold us on the Infiniband connectivity as a way to make a possible future transition to Exadata easier. However the pre-sales (more...)

Oracle Database 11gR2 ( installation on Oracle Linux 6.4

In this post, I’m installing the Oracle Database 11g Release 2 ( software on Oracle Linux 6.4, along with optional instructions on how to apply the latest Patch Set Update (PSU) to your new Oracle home. First and foremost, before you start, make sure your Linux server meets the minimum hardware requirements: 1GB of RAM (plus


Best of Oracle Security 2013

I just uploaded my DOAG 2013 presentation “Best of Oracle Security 2013“.


This presentation shows how to bypass Oracle Data Redaction, become DBA using CREATE ANY INDEX, Hide information from Oracle Auding using VPD and more…


SQL> select * from scott.credit_card where 1=ordsys.ord_dicom.getmappingxpath((card_id),user,user);


Decrypt Oracle and database link passwords

At Derbycon 3.0, László Tóth and Ferenc Spala  gave a a new presentation “What’s common in Oracle and Samsung? They tried to think differently… ” (Video). The main focus of the presentation was the Samsung encryption and a new framework called sandy but there was also a small (more...)

BI Mobile HD App

Finally got around to writing my long overdue post on the new BI Mobile HD app. To get on with it, without much ado, not to loiter, and all that... here goes.

The new BI Mobile HD app, version, can be downloaded from (more...)

Creating your first app with the BI Mobile App Designer

While creating sophisticated mobile apps that provide a rich feature set takes time, expectedly, what is wonderful about the recently launched Oracle Business Intelligence Mobile App Designer is the fact that you can be up and running without requiring a week-long training and a Master's degree in Computer Engineering.

Here's (more...)

Introduction to the BI Mobile App Designer

Oracle launched a brand new addition to its Business Intelligence Mobile solution - BI Mobile App Designer, which lets you create stunning, interactive mobile apps, literally within minutes. Apps created run on mobile devices running a reasonably modern mobile browser - that can handle HTML5 and jQuery - and are (more...)

White spaces and Map Views

When working with Map Views, you can choose to collapse the map formats panel on the left.

When you do that, the panel is hidden, but white space is displayed on either side of the map view, where the panel used to be.

Currently there is no option to remove (more...)

Fix for oradebug disable auditing available (

2 days ago I gave a presentation “Oracle 12c from the attackers perspective” at the DOAG SIG Security. I learned some interesting things, especially that a fix for the Oracle oradebug “disable auditing” problem is available since 9 months.

Oradebug allows to run OS commands and to enable/disable Oracle SYSDBA (more...)

portmap: unrecognized service on RHEL6

Original Post can be viewed at portmap: unrecognized service on RHEL6

Quick note for people using NFS for shared storage on RAC database. Till RHEL5 we had to ensure nfs,nfslock and portmap service has to be running. These services are required otherwise you will get following errors while mounting database


cursor: pin S wait on X

Original Post can be viewed at cursor: pin S wait on X

Few weeks back thread came up on oracle-l freelist regarding ”cursor: pin S wait on X” event . Tanel Poder replied to this thread with excellent explanation. You can read full thread here


This wait happens when your (more...)

Oracle Database Gateways 11g R2 (11.2) Installation and Configuration for heterogeneous connection from Oracle to Microsoft SQL database


Install the Oracle Database Gateways 11g R2 (11.2). See the screen snapshots of the installation here.


  • During the installation, the following+ default initialization parameter file is created:
dg4msql = Database gateway for Microsoft SQL Server. 
If you choose a different database option, use the appropriate path name.
  • Copy initdg4msql.ora to a new file init[MSSQL].ora.
[MSSQL] can be any meaningful name easier to refer to,  (more...)

Oracle SQL Developer Data Modeler 3.3 now available

Attention all data modellers - we are pleased to announce the release of SQL Developer Data Modeler 3.3. This release includes a new search, reports can be generated from search results, extended Excel import and export capabilities and more control and flexibility in generating your (more...)

Finally here: Oracle Instant Client 11gR2 for OS X

See the blog post over at Oracle for details, and be sure to send Christopher Jones an email (via the address in his post) stating you're an active user of the client. As Christopher mentions in his post,

You can really help us justify resources for the OS X bundle if you email me letting me know you are a fan. Since Instant Client is a free download, it is tricky for us to know how widely it gets used.

Jump to OTN to download, but please remember to email Christopher as well, if you're interested in seeing the client (more...)

11.2 AQ – Messages stuck in PROCESESED,WAIT State

Original Post can be viewed at 11.2 AQ – Messages stuck in PROCESESED,WAIT State

I had been working today on AQ issue where messages were not moving from WAIT to READY State.This was on database running on RHEL5u6(64 bit). I thought of quickly documenting it for easy reference When you enqueue record, you can specify delay after which record should be ready for dequeue. During this time, MSG_STATE [...] Weblog

Build an 11gR2 RAC cluster in VirtualBox in 1 Hour using OVM templates

[I originally posted this over at the Pythian blog. If you're not following it, you should! Way more content, by far smarter people than lil ol' me.]

After reviewing my blog post about running EBS OVM templates in VirtualBox, two of my teammates suggested that I work on something with potentially broader appeal. Their basic message was, "This is really cool for us EBS nerds, but what about the Core DBAs?"

So how does "11gR2 RAC in an hour" sound? :-) In this post, I'll demonstrate how to deploy the pre-built Oracle VM templates to create a two-node (more...)

Customize/Personalize Oracle APEX Workspace Environment

When you have multiple Oracle APEX environments, e.g., development, test, UAT and production, and for multiple groups, one of the confusing things is that sometimes developers are lost on which environment they’re working on. Most of technically proficient developers can make a distinction easily from the URLs they’re currently using. However, most of less technically proficient (e.g., business users) sometimes cannot.

A quick and simple solution here is to make a (more...)

Tailoring Fusion CRM

The journey for the Fusion CRM development team has been a long one. What a great feeling for all of us when Fusion Applications was officially released this year as Generally Available. During his keynote speech at this year's Oracle OpenWorld Steve Miranda reiterates that statement. Also during his session (more...)