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Date: Wed, 6 Jan 2010 10:12:59 +0800
Message-ID: <1e45bf881001051812h3907c6c0w52aeae27197c1c92@mail.gmail.com>
Subject: Re:Three questions about Hadoop
From: =?UTF-8?B?6Z6g5aSn5Y2H?= <dashengju@gmail.com>
To: general@hadoop.apache.org
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1. At the client side, one user's files are small files; but at the server
side, they will not put one user's file as a sperate file, usually they put
the same type content together, like a database. For example, the webpages
crawled from Internet are small pages, but they put them together as large
webpage data warehouse.

 2. "write-once and read-many times" is usually a charactor for data
warehouse. The webpages crawled from Internet are written to hadoop data
warehouse once, then they use those data to do many other analyse, read man=
y
times by different applications. Not all your data is "write-once and
read-many times".

 3. I do not know.

-----------------------------------
dashengju
+86 13810875910
dashengju@gmail.com

------------------ Original ------------------
  From:  "qin.wang"<qin.wang@i-soft.com.cn>;
 Date:  Tue, Jan 5, 2010 05:42 PM
 To:  "general"<general@hadoop.apache.org>;

 Subject:  Three questions about Hadoop


Hi team,


When I try to do some research on Hadoop, I have several high level
questions, if any comments from you it will do great help for me:


1. Hadoop assumes the files are big files, but take Google as an example, i=
t
seems the google result for user are small files, so how to understand the
big files=A3=BFAnd what=A1=AFs the file content for example?


2. Why are the files write-once and read-many times?


3. How to install other softwares on Hadoop, is there any special
requirements for the software? Do they need to support the Map/Reduce modul=
e
and then can be installed?


It will be very appreciated for your help.


=CD=F5 =C7=D9  Annie.Wang


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=A56=C2=A5
Zip code: 200 233
Tel:      +86 21 5497 8666-8004
Fax:     +86 21 5497 7986
Mobile:  +86 137 6108 8369

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