OGh APEX World 2015

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iAdvise Diamond Sponser APEX World 2015

After 5 successful earlier editions of the APEX World day, they chose a different venue for the 2015 edition. The ship SS Rotterdam was the setting for the annual APEX World event. For us, it was not only the location that was special, we were also official Diamond Sponsor of APEX World 2015! And a great day it was! Not only to meet a lot of nice people from (more...)

Find Out Values Of Bind Variables Across Multiple Executions Of A SQL

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The execution of the same SQL statement might result in different execution plans due to various reasons. In my last post,  I had demonstrated how the value of parameter OPTIMIZER_MODE can cause change in execution plan.  In this post, I will demonstrate that in case of skewed data distribution,  change in the value of a bind variables can also result in differing execution plans for the same statement. I will also explore how we can find (more...)

Some tips on creating, editing and manipulating and merging MP4 video files

Over the last few days, I have spent quite some time on creating several videos, demonstrating the use of technology. Creating this videos took a lot of time – especially the final step: merging five MP4 files together. This article provides some very brief pointers.

First of all, I have used SnagIt to create the initial screen-cams. Recent releases of SnagIt (note: this is not a free tool, although it is good value for its (more...)

Creating and scaling Dynamic Clusters using wlst

In my previous article, Creating and scaling Dynamic Clusters in Weblogic 12c, I described the creation and scaling of Dynamic Clusters. I used the Weblogic Console to create the Dynamic Clusters and change the number of servers.

Most of the time you will use some wlst scripting to create and manage your Weblogic environments.
In this article I will show you how to create Dynamic Clusters en how you can scale them.

The example (more...)

Avoiding the COMMIT bomb!

I’m an Oracle dinosaur, so I like using SQL Plus.  Its simple, fast, comes with every version and installation and platform, and I’m very familiar with it.  (And who knows, it might still be at the forefront of the Oracle development teams!  http://www.slideshare.net/hillbillyToad/sqlcl-overview-a-new-command-line-interface-for-oracle-database )

But there is one important thing I always take care of when I’m using SQL Plus, and it’s easiest to explain with an example.

You start (more...)

Oaktable World Las Vegas April 15, 2015 at Collaborate

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Wednesday April 15 at Collaborate 2015 Las Vegas room Mandalay K
For more information see Pythian’s Blog post.

Screen Shot 2015-04-08 at 10.03.53 AM

 

Screen Shot 2015-04-08 at 10.06.48 AM

 

 

What is Oaktable World ? Oaktable World is a day organized by members of the Oaktable network. The Oaktable network is a network of Oracle database tuning geeks. Among the members are Tanel Poder, Jonathan Lewis, Cary Millsap etc.  Oaktable network was created by Mogens Nørgaard back in 2001 or so and Mogens started (more...)

ADF 12.2.1 New Features

Oracle has just updated their ADF Statement of Direction, announcing that ADF 12.2.1 will be out in 2015. Here is what they are promising for this release:

The Next Version of Oracle ADF

Oracle is planning to deliver the next version of Oracle ADF – 12.2.1 – as part of the next release of Oracle Fusion Middleware 12.2.1 in 2015. Some of the focus areas for this version include:

Creating and scaling Dynamic Clusters in Weblogic 12c

Introduced in Weblogic 12.1.2, dynamic clusters is a great feature to scale your private cloud.
Dynamic clusters provides you easy scaling of Weblogic clusters by adding and removing managed server instances on demand. They contain one or more dynamic servers. These dynamic servers are based on a single servertemplate that guarantees that every member of the cluster is exactly the same.

Creating Dynamic Clusters

Let’s take a look at some of the possibilities (more...)

(OT) an idea for Easter (and well…every day)

I don’t travel as frequently as some people do, but with OpenWorld and various Oracle conferences each year, I definitely see my fair share of the inside of a plane and a hotel room.  To pass the time on flights, I try to read, but when you’re reading on a work-based trip, it’s a case of reading a page or two here and there, rather than a true extended session of relaxed reading.

The (more...)

Edition based redefinition – an apology

In April 2008 (wow, does time fly!) I used the following picture in my "11g features for Developers" presentation at the Australian Oracle User Group conference.

image

I think the picture is from the movie "Indiana Jones and the Last Crusade"… where they sought the Holy Grail.

I used the picture because I said that Edition Based Redefinition (EBR) was the Holy Grail of 24/7 Oracle based applications.  (Like most Oracle presentations at the (more...)

Observer effect

In physics, one important limitation of any experiment is the fact that an act of observation inevitably interferes with the observed process (“observer effect”). Same thing is true about databases. It is a well known fact that, for example, turning on tracing can significantly slow down the process for which it’s enabled. But there exist even nastier forms of this effect: for example, when you try to trace a SQL statement using nested loop batching mechanism, (more...)

sar -d on Linux

I started using sar -d to look at disk performance on a Linux system this week and had to look up what some of the returned numbers meant.  I’ve used sar -d on HP Unix but the format is different.

Here is an edited output from a Linux VM that we are copying files to:

$ sar -d 30 1
Linux 2.6.32-504.3.3.el6.x86_64 (myhostname)  04/01/2015      _x86_64_        (4 CPU)

05:26:55 PM        (more...)

In-memory – can you REALLY drop those indexes ?

Its not a hard sell to convince anyone that a whopping huge great chunk of compressed column-based memory is going to assist with those analytic-style queries.  The In-memory option seems a natural fit, especially for those people where the bottleneck in their infrastructure is the capacity to consume data from storage.

What perhaps a more interesting area of investigation is the claim that In-memory will also be of benefit in OLTP systems, where (to (more...)

Enterprise Manager is not able to connect to the database instance

Solution :

check the sysman and dbsnmp account status, If expired, please activate
SQL> select username,account_status from dba_users where username =’SYSMAN';

USERNAME ACCOUNT_STATUS
—————————— ——————————–
SYSMAN EXPIRED

SQL> select username,account_status from dba_users where username =’DBSNMP';

USERNAME ACCOUNT_STATUS
—————————— ——————————–
DBSNMP OPEN

 

So sysman account has been expired.  Please activate with old password and also Please check if this account has been locked, please unlock this account.

 

SQL> alter user sysman identified by Admin123;

(more...)

Try Oracle 12c VM with Delphix download


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 photo by Jose Maria Cuellar (CC 2.0)

Thanks to Leighton Nelson who pointed out  that :

Oracle has a pre-installed Linux VM with 12c

Delphix as well has a pre-installed   trial version 

Download both of these and start them up in Virtualbox and you can start virtualizing your PDBs.
The Oracle pre-installed VM has a few eccentricities that have to be addressed before using it. There is no IP address and there (more...)

Oracle Database Transactions and Locking Revealed, by Tom Kyte and Darl Kuhn

I recently came across the book called “Oracle Database Transactions and Locking Revealed” by Tom Kyte and Darl Kuhn. Usually, any new book by Tom Kyte is a big deal and acquires a huge following very quickly. Strangely enough there was only a single review on the Amazon, before I added my own.

For the reasons unknown to me, this book is literally ignored. I haven’t seen posts on the oracle-l about it, on the (more...)

PostgreSQL Hints and DBMS_STATS

For those who don’t know,‭ ‬it is now possible to use hints on PgSQL.‭ ‬Here
is how things work:

-‭ ‬Download and install the extension from the home page:

‭  ‬http://sourceforge.jp/projects/pghintplan/

If you are using Red Hat derivative,‭ ‬like me,‭ ‬it’s a simple RPM package.‭ ‬Check the content of the package,‭ ‬like this:

[‬mgogala@pg91‭ ~]‬$‭ ‬rpm‭ ‬-qa|grep pg_hint

pg_hint_plan93-1.1.3-1.el6.x86‭_‬64‭
[‬mgogala@pg91‭ ~]‬$
‭[‬mgogala@pg91‭ ~]‬$‭ ‬rpm‭ ‬-ql pg_hint_plan93-1. (more...)

WHEN OTHERS … sometimes just not enough

We currently are working on a bug with Oracle Support with dbms_stats in 12.1.0.2.

That may be the subject of a latter post, but in a nutshell, here’s the issue

SQL> exec dbms_stats.gather_table_stats('MY_SCHEMA', 'MY_SCHEMA');
BEGIN dbms_stats.gather_table_stats('MY_SCHEMA', 'MY_SCHEMA'); END;
 
*
ERROR at line 1:
ORA-21700: object does not exist or is marked for delete

Now obviously that’s not meant to be happening, and it pertains to incremental stats on a database (more...)

DCLI to back up Oracle home and inventory before patch

I was preparing for my weekend patch of our Exadata system and I needed to back up all of our Oracle homes and inventories on our production system.  On our 2 node dev and qa clusters I just ran the backups by hand like this:

login as root

cd /u01/app/oracle/product/11.2.0.4

tar -cvf - dbhome_1 | gzip > dbhome_1-20150211.tgz

cd /u01/app

cp -r oraInventory oraInventory.20150211

But the production cluster has 12 nodes (more...)

v$object_usage catches me out every time :-)

 

Every …. single …. time….

Why does index monitoring make me scratch my head and charge off to google so many times…Well, I’m over it, so time to put it on my blog (even though its already on many other places) so I do not get caught out anymore :-)

It always starts like this:

  • Turn on index monitoring on some indexes
  • Wait…
  • Come back later, and get ready to check on my results
  • (more...)