Schema and User 101

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| Jan 22, 2013

Schemas and users are frequently used interchangeably as if they were the same thing. For the most part, that's ok. In Oracle the concepts are so tightly coupled that thinking of them as the same thing is not really that far wrong. 


In reality, a user is a database account that is given a password and permissions. A schema is a container, or namespace, for containing schema objects. Schema objects are things like tables, views and indexes.


In Oracle, when a us

How long did Oracle materialized view refresh run?

The LAST_REFRESH_DATE column of the DBA_MVIEWS or the LAST_REFRESH column of the DBA_MVIEW_REFRESH_TIMES indicates the start refresh time. But what if we’d like to find out how long the refresh of the materialized view really takes. Well, we can query the DBA_MVIEW_ANALYSIS.

For Complete Refresh, the refresh duration will be in the FULLREFRESHTIM column of the DBA_MVIEW_ANALYSIS. For Fast Refresh duration, it will be in the INCREFRESHTIM column.

Both values are in seconds.

SELECT mview_name,  (more...)

My Presentations

I finally created a page and put up all my presentations. Actually, it's not all of them. I can't find about a half dozen or so that I know I've done and I think there are a couple more. For example, I used to do a security presentation and I can't find that one. I have several that I created while working different places and I can't find those either. Those would be my data (more...)

Reinstalling an Oracle Database Appliance Part 3

An Oracle Database appliance is a set of standard hardware and software molded together to created a 2 node RAC cluster that is easy to deploy. In parts 1 & 2 i talked about what methods you can use to reformat or erase the Oracle Database Appliance and rebuild it. (more...)

Restoring a Database with Rman Controlfile Parameters

There are occasions when you recieve a complete backup of a database from a  place different then yours and have to do a restore. normally a restore is simple . put the files in a directory run rman catalog on them and you are done. but what if you have rman (more...)

Oracle Throws in the Towel on VMware Licensing – Reprise

Given the incredible number of comments I received on my last blog post, and the content of those comments, it is very obvious that folks are extremely confused by what I meant by that post, as well as the comments by Mr. Garsthagen (Oracle Director Level Employee), referenced in that post.

The confusion is typified by the following comment, the most recent I have received:

Oracle does not recognize either (Vmware/DRS Affinity) as a hard partition

First, to be completely clear, I have never stated, nor do I believe, that VMware (or any other software hypervisor for that matter) (more...)

Oracle Throws in the Towel on VMware Licensing

As all of my readers know, I have been a strong proponent of VMware virtualization of Oracle Database servers for license cost savings purposes. Predictably, Oracle has pushed back on this issue in the past. Well, they have now thrown in the towel.

In an online video, Richard Garsthagen, Director of Cloud Business Development EMEA for Oracle, has stated publicly that VMware host affinity rules (when combined with vMotion logging) work just fine, thank you very much, for purposes of establishing where Oracle software is "installed and/or running" for purposes of the Oracle Software License Agreement (OSLA).

Previously, (more...)

Oracle Database 12c – New Feature: Identity Columns


Well, Oracle Database 12c is not yet available but new features seems to be popping out in MOS. While troubleshooting Oracle Enterprise Manager Cloud Control 12c startup issues I came across Oracle Database 12c new feature called “Identity Columns”.

An Identity Columns is auto-incremented at the time of insertion just like in SQL Server. Going forward, I think you will not use Oracle Sequence anymore to generate unique values instead use Identity Columns.

For more information on this read:



Happy reading!!!

VMware: Maritz out, Gelsinger in. What does it mean for Oracle?

As many of you have heard by now, Paul Mauritz is out as CEO of VMware, and Pat Gelsinger (formerly COO of EMC, reporting directly to Joe Tucci) is replacing him.

The relevant question for those of us who care passionately about Oracle virtualization using VMware vSphere is:

What does this mean for VMware's BCA (Business Critical Applications: stuff like Oracle) strategy (which under Maritz was somewhat lacking)?

In my view, this is very, very good news indeed. The reason is simple: Paul Maritz was former Microsoft, and thus very Microsoft-centric. Under Maritz, VMware very successfully penetrated the Microsoft (more...)

Comments by Dave Welch of House of Brick on Oracle on VMware Licensing

I thought it worth republishing Dave Welch's (of House of Brick) comments to my discussion on the Everything Oracle at EMC online community on the subject of Oracle licensing costs on VMware vSphere configurations. Here are Dave's comments:

All,

Let me start by bringing all of you into the courtroom. There are three issues that you will observe me as counsel provide to the jury as part of my allowed instruction (I am not an attorney in real life).

I offer the definitions in this paragraph only to make this post as self-sufficient as possible and not with intent (more...)

VMware’s Official Support Statement Regarding Oracle Certification and Licensing

Stake in the Ground

VMware has put a stake in the ground with respect to Oracle licensing of VMware VMs running Oracle. The gist of this statement regarding certification, support, and licensing is that DRS host affinity rules, combined with vCenter audit trails showing where VMs have actually run, are sufficient for Oracle licensing purposes. The summary of the document states:

DRS Host Affinity rules can be used to run Oracle on a subset of the hosts within a cluster. In many cases, customers can use vSphere to achieve substantial licensing savings.

vCenter VMotion Logging

Concerning vCenter VMotion logging, the (more...)

NetApp’s ExaData Backup Play Reprise

I have received a fair number of responses to my previous post on this subject (some via comments and some via email). I thought the discussion worthwhile enough to punch it up a bit more here.

Backup

As I pointed out in the previous post, EMC can easily match NetApp's play to back up ExaData with the following:

EMCBackupSolution

As Geoff Rosser so correctly pointed out, this answer is incomplete. Yes, Data Domain is an awesome Oracle backup solution. Yes, it provides incredible deduplication rates for Oracle database environments. (Thanks, dynamox.) However, it is not the only viable solution from (more...)

NetApp’s ExaData Backup Play

There has been lots of material on the web recently concerning NetApp being able to backup ExaData. The purpose of this blog is to respond to that content, and state why NetApp's offering is rather lame, and actually offers nothing new.

The items on the web produced by NetApp are easy to find. I will not increase their Google hit rate by linking to them here. Suffice it to say, Neil Gerren's blog contains the principle content to which I will respond here. There is also NetApp technical report TR 4022, a 34 page tome, which I have read thoroughly. (more...)

Is ExaData an "Appliance"

My boss, Sam Lucido, raised the following question on the Everything Oracle at EMC website:

Appliances such as microwave ovens, refrigerators, iPods, iPads and TVs are excellent examples of the ease-of-use approach. Bringing the inherently complex world of Oracle databases together with the ease-of-use approach of appliances is challenging. By definition if Oracle Exadata is an appliance then its use should be simple, require relatively little maintenance and like a refrigerator do its job which in this case is run databases at extreme performance levels. If Oracle Exadata isn’t an appliance than what is it?

I found this question (more...)

Oracle: Rename single/RAC Database

Method 1: Recreate control file with the new DB name, the old tried and tested method.
Method 2: Use new utility called NID
Steps to rename Databases using the new NID utility:
1.) Stop database

[oracle@testing1]~% srvctl status database -d test
Instance test1 is running on node testing1
Instance test2 is running on node testing2

srvctl stop database -d test


2.) startup mount the database:

[oracle@testing1]~% sqlplus / as sysdba

SQL*Plus: Release 11.2.0.2.0 Production on Thu Jul 21 00:50:44 2011
Copyright (c) 1982, 2010, Oracle. All rights reserved.
Connected to an idle instance.
SQL> (more...)

Finding the Best Match With a Top-N Query

There was an interesting index related performance problem on Stack Overflow recently. The problem was to check an input string against a table that holds about 2000 prefix patterns (e.g., LIKE 'xyz%'). A fast select is needed that returns one row if any pattern matches the input string, or no row otherwise.

I believe my solution is worth a few extra words to explain it in more detail. Even though it’s a perfect fit for Use The Index, Luke it’s a little early to put it as an exercise there. It is, however, a very good complement (more...)

Clustering Factor: Row Migration’s Victim

This article describes the effects of a high row migration rate on the clustering factor and the optimizer’s ability to select the best execution plan.

In my previous article—Row Migration and Row Movement—I have demonstrated that the “insert empty, update everything” anti-pattern can lead to 100% row migration. This article continues the research on row migration and unveils surprising effects on the clustering factor. To be precise, the clustering factor can become completely bogus in presence of a very high row migration rate. Once the clustering factor is “wrong”, it’s just a finger exercise to construct an optimizer (more...)

Ten Years Gone

I've been pretty quiet lately, because I'm in a transitional period. After 10 years on documentation for Oracle Database and other enterprise server products, I'm switching to the InnoDB group that already works with MySQL. New development environments, new customers, it's an exciting time!A decade seems to be the right timeframe for me. It was 10 years at IBM before that. Check back in 2019, I'm

Future of Relational Database

I read an interesting article on RWW about future of relational database; thought it might be of interest to you too!

This article talks about the emerging database (key/value database) and compares it to RDBMS. One of the interesting things being that you may not be able to perform JOIN operation. It is being described as the suitable model for cloud service provides (and pay-as-you-go service providers) and big players like Amazon (SimpleDB), Google (AppEngine Datastore), Microsoft (SQL Data services) have already started the offering. There are non-cloud providers too like - CouchDB (more...)

You’ve Got to Fight for Your Invoker’s Rights

This post is about a PL/SQL feature that doesn't get enough respect, "invoker's rights".First off, what's its real name? Depending on the source, you'll see the feature name spelled "invoker's rights", "invokers' rights", or "invoker rights". That makes a difference -- you'll get different results in Google depending on what combination of singular, plural, and possessive you use. And to be