Microsoft TerraServer: A Spatial Data Warehouse.pdf
5墨值下载
? 1 ?
Microsoft TerraServer: A Spatial Data Warehouse
Tom Barclay
Jim Gray
Don Slutz
June 1999
Revised February 2000
Technical Report
MS-TR-99-29
Microsoft Research
Advanced Technology Division
Microsoft Corporation
One Microsoft Way
Redmond, WA 98052
? 2 ?
Microsoft TerraServer: A Spatial Data Warehouse
Tom Barclay
Microsoft Research
301 Howard St., Suite 830
San Francisco, CA 94105
415 778 8223
tbarclay@microsoft.com
Jim Gray
Microsoft Research
301 Howard St., Suite 830
San Francisco, CA 94105
415 778 8222
gray@microsoft.com
Don Slutz
Microsoft Research
301 Howard St., Suite 830
San Francisco, CA 94105
415 778 8226
dslutz@microsoft.com
ABSTRACT
Microsoft® TerraServer stores aerial, satellite, and topographic
images of the earth in a SQL database available via the Internet. It
is the world’s largest online atlas, combining eight terabytes of
image data from the United States Geological Survey (USGS) and
SPIN-2. Internet browsers provide intuitive spatial and text
interfaces to the data. Users need no special hardware, software,
or knowledge to locate and browse imagery. This paper describes
how terabytes of “Internet unfriendly” geo-spatial images were
scrubbed and edited into hundreds of millions of “Internet
friendly” image tiles and loaded into a SQL data warehouse. All
meta-data and imagery are stored in the SQL database.
TerraServer demonstrates that general-purpose relational database
technology can manage large scale image repositories, and shows
that web browsers can be a good geo-spatial image presentation
system.
Keywords
Geo-spatial, VLDB, image databases, internet.
1 Overview
The TerraServer is the world's largest public repository of
high-resolution aerial, satellite, and topographic data. It is
designed to be accessed by thousands of simultaneous users
using Internet protocols via standard web browsers.
TerraServer is an image “tile” server that delivers a set of
raster images based on a users search criteria. Once an
image of interest is located, users can pan, zoom in, zoom
out, or display meta-data about the image they are viewing.
The TerraServer is a multi-media data warehouse. It differs
from a traditional data warehouse in several ways: (1) it is
accessed by millions of users, (2) the users extract
relatively few records (thousands) in a particular session
and, (3) the records are relatively large (10 kilobytes). By
contrast, classic data warehouses are (1) accessed by a few
hundred users via proprietary interfaces, (2) queries
examine millions of records, to discover trends or
anomalies, (3) the records themselves are generally less
than a kilobyte. In addition, classic data warehouse queries
may run for days before delivering results. Initial results
typically cause users to modify and re-run queries to further
refine results.
One thing the TerraServer has in common with classic data
warehouses is that both manage huge databases: several
terabytes of data. TerraServer’s topographic maps cover all
of the United States at 2 meter resolution 10 million square
kilometers), the aerial photos cover 40% of the United
States today (3 million square kilometers) at one-meter
resolution, and 1% of the urban areas outside the United
States (1 million square kilometers) at 2 meter resolution.
This report describes the design of the TerraServer and its
operation over the last 18 months. It also summarizes what
we have learned from building and operating the
TerraServer.
Our research group explores scaleable servers. We wanted
first-hand experience building and operating a large
Internet server with a large database and heavy web traffic.
To generate the traffic we needed to build an application
that would be interesting to millions of web users.
Based on our exposure to the EOS/DIS project [2], we
settled on building a web site that serves aerial, satellite,
and topographic imagery. We picked this application for
four reasons:
1. The web is inherently a graphical environment, and these
images of neighborhoods are recognizable and interesting
throughout the world.
2. We believed this application would generate the billions of
web hits needed to test our scalability ideas.
3. The data was available. The USGS was cooperative, an
since the cold war had ended, other agencies were more able
to share satellite image data. The thaw relaxed regulations
that had previously limited the access to high-resolution
imagery on a global basis.
4. The solution as we defined it – a wide-area, client/server
imagery database application stored in a commercially
© ACM 2000.
This article appeared in the Proceedings of the ACM
SIGMOD, May 2000 in Austin, TX.
Permission to make digital or
hard copies of part or all of this work for personal or classroom use
is granted without fee pro
vided that copies are not made or
distributed for profit or commercial advan
tage and that copies bear
this notice and the full cit
ation on the first page. Copy
rights for
components of this work owned by others than ACM must be
honored. Abstracting with credit is permitted. To copy other
wise, to
republish, to post on servers or to redistribute to lists, re
quires prior
specific permission and/or a fee.
of 15
5墨值下载
【版权声明】本文为墨天轮用户原创内容，转载时必须标注文档的来源（墨天轮），文档链接，文档作者等基本信息，否则作者和墨天轮有权追究责任。如果您发现墨天轮中有涉嫌抄袭或者侵权的内容，欢迎发送邮件至：contact@modb.pro进行举报，并提供相关证据，一经查实，墨天轮将立刻删除相关内容。
下载排行榜
文档被以下合辑收录
评论