Re: By default, LOB store in line or out of line?

From: du shenglin <shenglin.du_at_gmail.com>
Date: Sun, 22 Apr 2012 05:15:56 +0800
Message-ID: <CAGpGbohnYmcY_am7bBxxnNHAONynVybH8Hfcw=tkk0=j+Kt=Yg_at_mail.gmail.com>

I think the dba_lobs.in_row can tell you about enable/disable in row by default when creating table.
If you use UTF8, LOB will use double size than varchar2 because the multiple charact sets.(i am not sure if it's good to say as this). Tanel Poder have a good document about LOB 'LOB Internals and Performance Tuning' , you can search it on google
Thanks
Shenglin
On Sat, Apr 21, 2012 at 11:34 PM, Leyi Kamus Zhang <kamusis_at_gmail.com>wrote:

> Hi Lists
> According to the Doc as below:
> *Oracle® Database Application Developer's Guide - Large Objects
> 10g Release 2 (10.2)*
> Part Number B14249-01
>
> In Chapter 4 there are 2 graph：
> 1. LOB values are stored out-of-line when any of the following situations
> apply:
>
> *By default. That is, if you do not specify a LOB parameter for the LOB
> storage clause when you create the table.*
>
> 2. ENABLE or DISABLE STORAGE IN ROW Clause
>
> You use the ENABLE | DISABLE STORAGE IN ROW clause to indicate whether the
> LOB should be stored inline (in the row) or out-of-line.
>
> Note:
> You may not alter this specification once you have made it: if you ENABLE
> STORAGE IN ROW, then you cannot alter it to DISABLE STORAGE IN ROW and vice
> versa.
> *The default is ENABLE STORAGE IN ROW.*
>
> Document error? Which one is the TRUTH? or I misunderstanding something?
>
> Based on our test, even every LOB has only 2080bytes(less than 4000bytes),
> LOB is stored OUT of line, but dba_lobs.in_row=YES.
>
> --
> Kamus <kamusis_at_gmail.com>
>
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Received on Sat Apr 21 2012 - 16:15:56 CDT