Re: mysql overhead

[David T-G]

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Stefan, et al --

...and then Stefan Hinz said...
% 
% MyISAM tables (the default table type in MySQL) become fragmented
...
% 
% If you don't optimize fragmented MyISAM tables, they will become slow
% to scan because the operating system will need more time for disk
% operations.
% 
% Details: http://www.mysql.com/doc/en/OPTIMIZE_TABLE.html

Very interesting.

A) Is this the sort of thing that people do from a cron job to make sure
that they don't have too much fragmentation?  Does it actually show up
more than once in a milennium for most people?

B) What about the postscript at that URL describing problems with this
command?

  1) Are there still problems?

  2) Is there yet any concrete data on the problems?

a) Is it repeatable and deterministic or still an unknown target?

b) Is it better to OPTIMIZE more often, and thereby make little
optimizations, to avoid such problems, or is any OPTIMIZE a game
of roulette and so one should do it only when absolutely needed?

  3) What does one do if one has a fragmented table and yet cannot
  optimize it because of said problems?


TIA & HAND

mysql query,
:-D
- -- 
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(play) [EMAIL PROTECTED] * society and not sufficient moral courage.
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Re: mysql overhead

[Stefan Hinz]

Ciprian,

> I am using PhpMyAdmin and today I got a red message saying that one
> table has overhead and I need to optimize the table. 
> This is the first time I got this message, I looked online and I
> understood why it shows. But my question is: can I do something to avoid
> it? What effects daoe the overhead have on a table?

MyISAM tables (the default table type in MySQL) become fragmented
when you delete records (this can even happen when you update records,
if your table format is dynamic). You cannot avoid this effect if
you're using MyISAM tables.

If you don't optimize fragmented MyISAM tables, they will become slow
to scan because the operating system will need more time for disk
operations.

Details: http://www.mysql.com/doc/en/OPTIMIZE_TABLE.html

Regards,
--
  Stefan Hinz <[EMAIL PROTECTED]>
  iConnect GmbH 
  Heesestr. 6, 12169 Berlin (Germany)
  Telefon: +49 30 7970948-0  Fax: +49 30 7970948-3


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mysql overhead

[Ciprian I. Acatrinei]

Hi,

I am using PhpMyAdmin and today I got a red message saying that one
table has overhead and I need to optimize the table. 

This is the first time I got this message, I looked online and I
understood why it shows. But my question is: can I do something to avoid
it? What effects daoe the overhead have on a table?


Thank you,
-- 
Ciprian <[EMAIL PROTECTED]>


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MYSQL Overhead

[John Chang]

In some of my tables I see overheard.  What does it mean and does it mean I 
have to optimize it every time?  I seem to see it everyday. SQL


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