Re: Row migrated in new data blocks

From: Fabio Cannavaro <fatti_at_icazzi.tuoi>
Date: Thu, 17 Aug 2006 17:39:46 +0200
Message-ID: <44e48d86$0$30249$4fafbaef@reader1.news.tin.it>

frank.van.bortel_at_gmail.com wrote:

> someone is mixing up row migration and row chaining here.
> The OP decribes migration, as I read it.
> I have never seen performance tests examining this, so,
> be our guest.
> Chaining is when a row doesn't "fit" and thus uses two (or more)
> blocks.
> Migrated rows will not affect full table scans, it will affect indexed
> reads.

From what I can see from explanation on the book, the more overhead is because of the pointing from old row to new migrated row.

I'll investigate in asktom :) Received on Thu Aug 17 2006 - 10:39:46 CDT