Re: Problem: database table/index sizing for Sum Length Columns greater than Available Data Space

From: Brendan Newman <bis_at_ibm.net>
Date: Tue, 27 Jul 1999 12:30:00 -0400
Message-ID: <379ddf6f_at_news1.us.ibm.net>


Thanks for your help - but I need help for tables, not indexes.

fumi wrote in message <7nkic9$g89$3_at_news.seed.net.tw>...
>
>Brendan Newman <bis_at_ibm.net> wrote in message
news:379c4cd5_at_news1.us.ibm.net...
>> Hi there,
>>
>> I am trying to size Oracle 8.x tables and am having difficulty due to
>> the fact that the formulas Oracle gives are only appropriate if your
Space
>> Used Per Row (i.e. Sum Length Columns + Overhead) is less than your
>> Available Data Space (i.e. Block_Size - Header Space - Pct_Free_Space).
>
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>The max total size of indexed columns is "40%*db_block_size - some
overhead".
>In some version, the manual says "half of db_block_size - some overhead".
>
>> What if Space Used Per Row >= Available Data Space? That is, what if
>> you have big columns which are much bigger than your block size and you
>> don't want to increase the block size?
>
>
>You will get an error message 'ORA-01450: maximum key length n exceeded'
>when creating the index.
>In general, such an index is impractical and poor-designed.
>You should re-examine your database design.
>
>> If you could point me to where there are formulas for this particular
>> case please let me know. Thanks. My e-mail is bis_at_ibm.net.
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Received on Tue Jul 27 1999 - 18:30:00 CEST

Original text of this message