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Home -> Community -> Mailing Lists -> Oracle-L -> RE: ANTs Data Server?
I agree with that 100%.
(Gosh, stop and consider the sheer
*courage* required to agree with
Cary on something :-P).
A lot of the "molasses-point" stuff I've seen is not
in my 15 tb san with 24 Gb of cache, it's in my sad and
sorry little Sun cpus, apocryphally named "Ultra Sparcs".
( Must describe their final catastrophic failure mode and
concomitant fireworks.)
There's a great little article "out there"
ftp://ftp.cs.wisc.edu/wwt/vldb99_dbms_eval.pdf
"Abstract
Recent high-performance processors employ sophisticated techniques to overlap and simultaneously execute multiple computation and memory operations. Intuitively, these techniques should help database applications, which are becoming increasingly compute and memory bound. Unfortunately, recent studies report that faster processors do not improve database system performance to the same extent as scientific workloads. Recent work on database systems focusing on minimizing memory latencies, such as cache-conscious algorithms for sorting and data placement, is one step toward addressing this problem. However, to best design high performance DBMSs we must carefully evaluate and understand the processor and memory behavior of commercial DBMSs on today's hardware platforms.
In this paper we answer the question "Where does time go when a database system is executed on a modern computer platform?"
We examine four commercial DBMSs running on an Intel Xeon and NT 4.0. We introduce a framework for analyzing query execution time on a DBMS running on a server with a modern processor and memory architecture. To focus on processor and memory interactions and exclude effects from the I/O subsystem, we use a memory resident database. Using simple queries we find that database developers should
(a) optimize data placement for the second level
of data cache, and not the first,
(b) optimize instruction placement to reduce
first-level instruction cache stalls, but
(c) not expect the overall execution time to
decrease significantly without addressing stalls related to subtle implementation issues (e.g., branch prediction).
-----Original Message-----
From: Cary Millsap [mailto:cary.millsap_at_hotsos.com]
Sent: Wednesday, September 01, 2004 9:59 AM
To: oracle-l_at_freelists.org
Subject: RE: ANTs Data Server?
I just don't get the whole "cache everything, and everything will be ok" argument. The vast majority of the slow tasks I've seen in the past ten years have all executed "in cache" to begin with!
...And fixing them has, almost every time, required either optimization = of SQL, or optimization of the application code that calls the SQL. I just don't see how /any/ database can defend itself against all the types of abuse that an application developer can throw at it.
Cary Millsap
Hotsos Enterprises, Ltd.
http://www.hotsos.com
* Nullius in verba *
Upcoming events:
- Performance Diagnosis 101: 9/14 San Francisco, 10/5 Charlotte, 10/26
Toronto
- SQL Optimization 101: 9/20 Hartford, 10/18 New Orleans - Hotsos Symposium 2005: March 6-10 Dallas - Visit www.hotsos.com for schedule details...
-----Original Message-----
From: oracle-l-bounce_at_freelists.org = [mailto:oracle-l-bounce_at_freelists.org]
On Behalf Of Peter Robson
Sent: Wednesday, September 01, 2004 8:14 AM
To: Jonathan Gennick
Cc: oracle-l_at_freelists.org
Subject: Re: ANTs Data Server?
Jonathan,
Wednesday, September 1, 2004, 2:03:04 PM, you wrote:
JG> Has anyone ever heard of these guys?
JG> http://www.antssoftware.com/index.htm
No, I have not heard of them.
The web site refers to in-memory products, and Cache immediately springs to mind. If you have ever looked at that product, and can remember Adabas, there are remarkable similarities. The key question to ask of these vendors is what data model their product supports. The answers can be interesting...
peter
edinburgh
.............
--=20
mailto:pgro_at_bgs.ac.uk
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