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From:Michael Widenius Date:September 1 1999 11:07am
Subject:Re: Index files surprisingly large
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>>>>> "Jules" == Jules Bean <jmlb2@stripped> writes:

Jules> Bother...
Jules> Something broken on the machine I'm running mysqlbug on, and mails don't
Jules> go through to the list (or, apparently, Monty).

<cut>

>> # isamchk -dvv my_table
>> ISAM file:     my_table
>> Isam-version:  2
>> Creation time: 1999-08-26 15:40:16
>> Recover time:  1999-08-26 17:33:13
>> Data records:           9655579  Deleted blocks:              0
>> Datafile  Parts:        9655579  Deleted data:                0
>> Datafile pointer (bytes):     4  Keyfile pointer (bytes):     3
>> Recordlength:               180
>> Record format: Packed
>> table description:
>> Key Start Len Index   Type                       Root  Blocksize    Rec/key
>> 1   1     4   unique  long                   78710784       1024          1
>> 2   5     160 multip. text                  2056176640       1024      16940
>> 3   165   16  multip. text packed stripped  2140120064       1024          1

>> Field Start Length Type
>> 1     1     4      no zeros
>> 2     5     160    no endspace
>> 3     165   16     no endspace

hi!

Compare key 2 & 3

The difference is that key 2 is 'packed and stripped' while key 2
isn't.  This means that every key will take 160 bytes!

The reason is that the old ISAM code can't compress keys > 127 bytes.

This is fixed in MyISAM.

Fix:

Change the key to 127 character or upgrade to MySQL 3.23

Regards,
Monty
Thread
Re: Index files surprisingly largeJules Bean1 Sep
  • Re: Index files surprisingly largeMichael Widenius1 Sep
Re: Index files surprisingly largeJules Bean1 Sep
  • Re: Index files surprisingly largeMichael Widenius2 Sep