ORA-27101 Shared Memory Realm does not exist

What is the cause of the "ORA-27101 Shared Memory Realm does not exist"? How do I resolve this?

CLOBS, from 11g to 12c

If you are a regular user of LOB’s in the database, take care when you switch from 11g to 12c.  Notice the subtle difference:

In 11g, you are permitted to, and recommended to, use SECUREFILE lobs, but they are not the default

SQL> select name, value
  2  from v$parameter
  3  where  name = 'db_securefile';

NAME                                     VALUE
---------------------------------------- ---------------
db_securefile                            PERMITTED

In12c, SECUREFILE lobs will be the default.

SQL> select name, value
  2  from v$parameter

AIOUG Sangam15 : The Journey Begins

The day started pretty early. I was packing at 00:00 and the alarm went off at 05:00. Nothing like last minute packing to focus the mind. :)

The taxi to the airport was good. The driver was interesting, speaking to me about his visits to India and Pakistan. It certainly helps pass the time when the driver is chatty.

I wasn’t able to check-in online, but there was no queue at the check-in desk, so that was quick. (more...)

A Problem with REVOKE

If you grant the DBA role to a user, Oracle also grants it the UNLIMITED TABLESPACE system privilege. If you then revoke the DBA role from this user, Oracle also revokes its UNLIMITED TABLESPACE system privilege. This isn’t too much of an issue.
However, if you grant the UNLIMITED TABLESPACE system privilege to a user by itself THEN grant it the DBA role, Oracle seems to have no idea where the UNLIMITED TABLESPACE system (more...)

Lost SYSMAN password OEM CC 12gR5

I run my own licensed Oracle products in-house.  Since it is a very simple environment, largely used to learn how things run and verify what I see at customer sites, it is not very active at all.  But it is important enough to me to keep it maintained.

After a bit of a hiatus in looking at the OEM, which is at 12cR5 patched, I went back and noted that I was using the wrong (more...)

Oracle Week 2015: Oracle Advanced PL/SQL Presentation

As I said in my earlier post about Oracle Week 2015, this is one of the biggest database related educational (non-sale oriented) convention in Israel. None of the session is designed for selling any products (but consultant use it to showcase their abilities hoping to sell some professional services :)). Yesterday was my second daylong session in this convention this year . This time we talked about advanced features in PL/SQL and some new features of (more...)

howto: github – talks branch

A couple of months ago I did a presentation and decided to put the files up in github (https://github.com/karlarao/conference_eco2015) just because I wanted to move away from dropbox for my scripts and resources. Well, that was very convenient because the audience can just download the master zip file and that’s it! But then I figured I don’t want to have the next presentation on another repo and it would look pretty messy (more...)

How Terminal Emulation Assists Easy Data Management

Just about every company will need terminal emulation at some point. Yours may not need it now, but as time goes on, the day will come when you need information that can only be accessed with an emulator. This software allows a computer to basically take on the functionality of an older version. Doing so makes it possible for the user to access data that would otherwise be impossible to find. If you’re not sold (more...)

Windows Task Scheduler CMD

Don’t get me wrong. GUI can be terrific but it does have its place.

When the connection between you and the the target host are multiple servers across the continent, the latency will drive me crazy mad.

Hence, my exploration to learn more command line.

Enough of my rant, let’s demo.

Tested on Windows 7


Microsoft Windows [Version 6.1.7601]


List by Folders:

C:Usersdinh>schtasks /query /fo table /nh

DropboxUpdateTaskUserS-1-5-21-992222644- 18-Nov-2015  (more...)

Extent Allocation

Some references on extents dealing with extent trimming, initial extent for parallel load, tablespace fragmentation, etc…


Parallel Load: Uniform or AutoAllocate extents?

Tom Kyte covers this problem in great details in his post Loading and Extents

Initial Extent Size of a Partition Changed to 8MB from 64KB After Upgrade to or Later (Doc ID (more...)

Using EMCLI List Verb to Get Detailed Information of EM Targets

After the presentation about EMCLI at DOAG 2015, someone asked me how we can list database targets based on their operating systems. In my presentation, I told that there are more than 70 verbs which starts with “get_” and help you fetch information about EM objects, and if you can’t find what you’re looking for, you can use the “list” verb which is probably the most powerful verb of EMCLI. Now I try to show (more...)

Oracle Wait Events Investigated with Extended Stack Profiling and Flame Graphs

Topic: this post is about investigating Oracle wait events using stack profiles and flame graphs extended with OS-process state and Oracle wait event details.

Context: The case of the DB Time > CPU Time + Wait Time

Oracle instrumentation provides wait event and CPU time accounting, a powerful and readily accessible data source for performance troubleshooting. An Oracle session at a given point in time is either on CPU, for example when processing data from cache, (more...)

Segment Creation Deferred not Available in Standard Edition

If you use Oracle Standard Edition to create a production database, you need to be sure to create any corresponding test databases in Oracle Standard Edition too. Otherwise you may find that some SQL might be tested successfully, only to fail when you implement it in production. You can see what I mean in the example below. First I created a table with segment creation deferred in the Oracle Enterprise Edition test database:
C:UsersAJ0294094>sqlplus (more...)

Actively Manage Your OMR with EMDIAG

Oracle provides the OMR analysis tools EMDIAG and repvfy so we can perform detailed management repository analysis and maintenance just like the pros.

Werner de Gruyter (Yoda), the father and caretaker for EMDIAG, has provided a custom Information Publisher report that you can use to manage your system on a regular basis.

Create EMDIAG Report

EM CLI allows you to create an IP report by importing an XML definition of the report.  Create and save the XML (more...)

Brief about Workload Management in Oracle RAC

This is a brief article about workload management in RAC. I tried to cover different components of workload management in RAC and how they are configured at client side or server side. I haven’t gone into details of configuration steps but just mentioned in brief about how it can be done.

Readers are advised to refer Oracle documentation to understand details about configuration of workload management.

Workload management on RAC

There are 2 major components (more...)


This blog post is inspired on work I have been doing on Standard Edition databases and the returning confusion about what is and what is not part of Standard Edition.

DBA_FEATURE_USAGE_STATISTICS is a tool in determining license usage for the Oracle database. It is good to understand the implications of each entry, know what is happening in your database and thus be able to have a substantial conversation about the usage of your license, being (more...)

Oracle Wait Events Investigated With Extended Stack Profiling and Flame Graphs

Topic: this post is about investigating Oracle wait events using stack profiles and flame graphs extended with OS-process state and Oracle wait event details.

When create mview takes forever….

After having real work get in the way for a couple of weeks ( a major 9i->12c is proving 'interesting' at the moment - maybe even worthy of a talk at some point) I've been slacking a little on writing up any blog posts.

So lets make amends for that now with a short post on some mview creation quirks.

I've been working in the past day or so on a browsing system for our (more...)

Oracle Midlands : Event #12

Just a quick reminder, Oracle Midlands Event #12 is just around the corner.

This is the day after I get back from India, right after my first day back at work. It’s going to be really hard to drag myself there, but I know it will be worth it!






Oracle Midlands : Event #12 was first posted on November 16, 2015 at 3:59 pm.
©2012 "The ORACLE-BASE Blog". (more...)

EMCLI Python Script File to Create Users

I’ll give presentations at DOAG 2015 on Tuesday (tomorrow), and at the BGOUG Autumn Conference on Saturday. My presentation will be about EMCLI (Enterprise Manager Command Line Interface). I will try to explain the basics of EMCLI, its terminology, the important points, and how we can use it with bash for scripting. I’ll also speak about EMCLI Python scripting, very short but useful into to Python and then share some sample scripts. Because of the (more...)