----- Original Message -----
From: ""Martijn Tonies"" <m.tonies@stripped>
Sent: Thursday, March 16, 2006 8:59 PM
Subject: Re: NULL columns
>> When doing an insert using NULL in the insert request,
>> what really is being written in the column?
>> Is the word NULL being written?
>> Is any real space being consumed?
> In the cases that you really want to store NULL ;-)
> No, it's not the word "null".
> Of course space is consumed.
> How much depends, see, for example:
> This is for MyISAM, InnoDB behaves differently.
InnoDB's old table format in 4.1 and earlier kept a fixed-length column the
same length even when the value NULL was stored. That, of course, wasted a
lot of space. The advantage was less fragmentation in updates.
InnoDB's new table format in 5.0 does not use any space to store a NULL. The
column itself needs one bit to indicate whether the value is NULL or not.
> Martijn Tonies
> Database Workbench - development tool for MySQL, and more!
> Upscene Productions
> My thoughts:
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