RE: Teradata article about exadata

From: Ric Van Dyke <ric.van.dyke_at_hotsos.com>
Date: Wed, 27 Nov 2013 13:07:00 -0600
Message-ID: <C970F08BBE1E164AA8063E01502A71CF0220AF06_at_WIN02.hotsos.com>

About a 1000 years ago I worked on a major Teradata implementation. There are some interesting similarities between the two. However as Tim mentions they don’t have anything like PL/SQL (at least not that I’m aware of) and even the SQL implementation I found lacking. At that time they did have the upper hand on handling massive amounts of data, however today I think they have lost that battle as well. Oracle can easily handle the same volume of data rather easily.  

One of the basic differences between Teradata and Oracle (Exadata or not) is that Teradata works form a “shared nothing” architecture and Oracle is a “shared everything” architecture. Each AMP in Teradata can only access it’s slice of the data. Where as in Oracle any instance connected to a database can access any and all of the data. They work from an idea that data needs to be sliced and diced and only one “engine” so to say should be able to access any part of the data. So this idea of “shared disks” is somewhat of a wild concept to Teradata folks. (BTW- for fault tolerance each AMP can access some other AMP’s data in case an AMP fails, but in normal processing it can only access it’s part.)  

From: oracle-l-bounce_at_freelists.org [mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Tim Gorman Sent: Wednesday, November 27, 2013 9:42 AM To: oracle-l_at_freelists.org
Subject: Re: Teradata article about exadata  

Even prior to 12c ADO, ILM isn't unmanageable; you just have to know what you want and code for it.

In Teradata, which (I believe) still lacks an embedded procedural language equivalent to PL/SQL (is this true?), this is more problematic than for Oracle.  

On 11/27/2013 7:31 AM, Justin Mungal wrote:

        Oracle advocates the SAME allocation policy for data warehousing because it believes that in its shared disk environment this policy optimizes access performance across diverse access patterns to different tables. While it’s possible to control data allocation manually, as the number of tables grows, the complexity of specifying data placement manually becomes quickly unmanageable.          

        Hmm. The paper predates 12c ADO, So I'm guessing they consider 11g ILM to be "manual" data allocation that quickly becomes unmanageable?          

        Marketing...          

        On Wed, Nov 27, 2013 at 8:19 AM, Stephens, Chris <Chris.Stephens_at_adm.com> wrote:

        SGA/buffer cache and all the locks/latches/mutexes necessary to coordinate access to those buffers.         

        Teradata doesn't implement acid as far as I know.                                    

	-----Original Message-----
	From: Dba DBA [oracledbaquestions_at_gmail.com]
	Sent: Tuesday, November 26, 2013 11:02 PM Central Standard Time
	To: ORACLE-L
	Subject: Teradata article about exadata

	This is a marketing article. I have not used teradata or exadata. I think Teradata is basically Oracle running on custom hardware sold by Oracle that is specialized for DB performance.� 

	 

	anyone know what they mean by "shared disk"? Its on page 2.�

	I'd like to avoid an oracle fan argument. I know people who have used teradata and find it a very a good product.�

	 

	www.teradata.com/white-papers/Exadata-is-Still-Oracle/ <http://www.teradata.com/white-papers/Exadata-is-Still-Oracle/> 

	 

	While Exadata improves Oracle�s I/O performance, Exadata

	does not tackle Oracle�s underlying performance and scalability

	problems with large-scale data warehousing that stem from

	its shared disk architectural foundation.

	 

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Received on Wed Nov 27 2013 - 20:07:00 CET