From: Dan Nelson
Date: March 21 2002 4:41pm
Subject: Re: delete vs delete quick
List-Archive: http://lists.mysql.com/mysql/103782
Message-Id: <20020321164122.GC98076@dan.emsphone.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii

In the last episode (Mar 21), Viraj Alankar said:
> sql
> 
> I'm confused as to what 'delete quick' does and when to use it. The
> manual states:
> 
> If you specify the word QUICK then the table handler will not merge
> index leafs during delete, which may speed up certain kind of
> deletes.

Normally when you delete an entry from an index, if the deletion causes
an index block to become half-empty (or 25%, or whatever; depends on
the algorithm), mysql will start coalescing index blocks.  This results
in a smaller, more efficient index.

If you are simply deleting a bunch of records only to re-insert new
ones, there's not much use in trying to optimize the index halfway
through the operation.

-- 
	Dan Nelson
	dnelson@stripped