size of index

From: karsten reincke <kreincke_at_cl-ki.uni-osnabrueck.de>
Date: Mon, 21 Jun 1999 09:45:04 +0200
Message-ID: <376DED80.89B4B912@cl-ki.uni-osnabrueck.de>

hello;

(1) does exist any rule for computing the necessary size of an index?

we will have a table of more than 4 Million rows, each row containing more that 3K. and we want to create an index for two columns of that table, both being of type VARCHAR(40). what is the method for computing the size ofn that index?

(2) is this a good rule for computing the size of an index:

( (size of columntype) [+ (size of columntype) ...] ) * expected number
of rows )

in our example:

[ 40 B + 40 B ] * 4000000 = 320 MB

many thanks for your comments and/or your hints?

--

       salut d'Allemagne kr

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les chats cont les vrais hédonistes
et devraient être donc notre idéal.

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 karsten reincke [ 0541/9696223 ]
 kreincke_at_cl-ki.uni-osnabrueck.de Received on Mon Jun 21 1999 - 02:45:04 CDT