This may give you some answers:
http://arswiki.org/wiki/Oracle_Performance_Tuning#LOB_Storage

Regards,
Jarl

2009/4/24 Misi Mladoniczky <m...@rrr.se>:
> Hi David,
>
> Can anyone explain how it can get som MUCH bigger.
>
> I estimate that the new system took up 3-4 times as much data in the
> database, 45+Gb instead of 15Gb.
>
> The size of the CLOB for the empty 32000-char-field was 12000 bytes per
> record, 500Mb for 44000 records... Note that the data was empty on all
> rows.
>
> Does the system allocate empty space for each record in advance???
>
>        Best Regards - Misi, RRR AB, http://rrr.se
>
>> By default, 7.x is configured to always store LOB's out of row.  Once the
>> value is set all forms created after will store in row and out of row
>> depending on the data size for that field within the record.
>>
>> Not all the data is stored in row.  There is a limit where the switch is
>> made to store out of row for that record.  The issue was that data was
>> always stored out of row even if there was space to store the data in row.
>>
>> We were on 7.0.1 for a year or so before we found out about this behavior.
>>  Under 7.0.1 the size of the instance was growing faster than under 6.3.
>> We finally identified it was this issue with out of row storage of the
>> data.  BMC/Remedy sent me a procedure to switch our data.  I haven't run
>> it yet.  At this point I think we will wait until we migrate to a new
>> server.
>>
>> If I remember right Rick Cook did a lot of testing of in row and out of
>> row back under 7.0.1.
>>
>> Dave
>>
>> -----Original Message-----
>> From: Action Request System discussion list(ARSList)
>> [mailto:arsl...@arslist.org] On Behalf Of Misi Mladoniczky
>> Sent: Friday, April 24, 2009 8:04 AM
>> To: arslist@ARSLIST.ORG
>> Subject: Re: Oracle LOB getting very big
>>
>> Thanks David,
>>
>> That did the trick!
>>
>> You had to specify this before the forms were created, but we are still in
>> the testing environment, so this is ok.
>>
>> In this case I guess that the CLOB-data will be stored within the actual
>> row instead of the external table? Is there a size limit where the
>> CLOB-data is stored outside of the row?
>>
>>         Best Regards - Misi, RRR AB, http://www.rrr.se
>>
>> Products from RRR Scandinavia:
>> * RRR|License - Not enough Remedy licenses? Save money by optimizing.
>> * RRR|Log - Performance issues or elusive bugs? Analyze your Remedy logs.
>> * RRR|Translator - Manage and automate your language translations.
>> Find these products, and many free tools and utilities, at http://rrr.se.
>>
>>> Misi,
>>>
>>> I think you're seeing the in row/out of row issue with storage of LOB's.
>>> By default version 7.x stores out of row.  There is a switch so that new
>>> forms will store in row.  There is also a conversion routine from
>>> BMC/Remedy but I've not been comfortable running it.
>>>
>>> If your 7.1 server is not in production, you could try setting the in
>>> row
>>> parameter.  Deleting the form and importing the form definition again.
>>> Dave
>>> -------------------------
>>> dave.shell...@tycoelectronics.com
>>> (Wireless)
>>>
>>> ----- Original Message -----
>>> From: Action Request System discussion list(ARSList)
>>> <arslist@ARSLIST.ORG>
>>> To: arslist@ARSLIST.ORG <arslist@ARSLIST.ORG>
>>> Sent: Fri Apr 24 07:05:27 2009
>>> Subject: Oracle LOB getting very big
>>>
>>> Hi,
>>>
>>> I am moving data from a ARS 6.3.0 server to a 7.1.0 patch 6 server. Both
>>> are accessing an Oracle 10 database.
>>>
>>> In the target server, 3 LOBs are becomming very big. They are connected
>>> to
>>> large text fields (32000 chars) and a diary field.
>>>
>>> For example one of these text fields has no data in the column for any
>>> of
>>> the 44361 records. The resulting LOB is about 512 Mb in size...
>>>
>>> In the source 6.3 machine, the size is very small.
>>>
>>> Has anyone seen anything similar?
>>>
>>> The real problem is another form with 4 million records, where one LOB
>>> is
>>> 13 Gb in size...
>>>
>>> I am moving the data with RRR|Chive, which is exactly the same as using
>>> AR
>>> Import of an ARX-file. In other words by doing the API-calls
>>> ARGetEntry()
>>> and ARMergeEntry().
>>>
>>>         Best Regards - Misi, RRR AB, http://www.rrr.se
>>>
>>> Products from RRR Scandinavia:
>>> * RRR|License - Not enough Remedy licenses? Save money by optimizing.
>>> * RRR|Log - Performance issues or elusive bugs? Analyze your Remedy
>>> logs.
>>> * RRR|Translator - Manage and automate your language translations.
>>> Find these products, and many free tools and utilities, at
>>> http://rrr.se.
>>>
>>> _______________________________________________________________________________
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>>>
>>>
>>
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>
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