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Estimating size of a table with LOB column

Hi all,

The table in question has 4 fields:
UNID 19 chars
DATA 2147483647 (BLOB)
ROW 19 chars
DT 10 chars

Second column can take upto 2GB (attachments etc). So I am trying to figure out the growth of these attachments in the database in terms of space.

But the actual value in this column in not the attachment itself but a pointer/descriptor to this attachment stored somewhere on disk.

So when you estimate the size of the table it doesn't include the attachments size. It just estimates the size using the average size of the 3 fields plus the average size of the pointer.

So where are these LOB's stored on disk (Is it in the same tablespace) if so how do we estimate the growth of these attachments (as the tablespace has several other tables).

Thanks in advance
Dec 18 '07 #1
2 3444
Yeah, I've been looking for this information, too.
The thing about the descriptor is, it seems to be fairly useless for retrieving significant information, especially if your LOBS aren't logged. I haven't seen anything that will give you actual size info for the tablespace where the LOB is actually stored.

I really need this info, so any help from out there is appreciated.
Jan 8 '08 #2
No way.
We seriously have to upgrade to DB2 9 to have this capability?
Come on. How basic should that functionality be to DB operations and app development?

To anyone who is at 9, you do a select * from sysibmadm.admintabinfo because YOU have the structure that we don't. Presumably, you'll need to know the attachment's data object ID, which I assume you can get from the RID.

Unless I'm missing something. Pipe up, anybody who knows more.

I guess we're not alone, though. The functionality didn't exist in Oracle until this latest release, 11, either.
Jan 10 '08 #3

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