RE: How to calculate sizes of individual rows

From: Rich Jesse <>
Date: Thu, 21 May 2015 15:12:10 -0500 (CDT)
Message-ID: <>

Hey Jonathan,

> Your suspicion is correct - vsize() calculates the length of the data
> stored, but doesn't include the length byte(s).
> (In passing, Oracle switched from using vsize() to using sys_op_opnsize() a
> long time ago during stats collection).

Interesting that my samples using vsize and sys_op_opnsize return the same values. Hmmm...


Ahhh, now that you show me that link, I do remember, but it was while I was investigating the differences in storing histogram information between the two methods.

> For a simple picture, just add one per column - knowing that this won't be
> correct for columns holding more than 250 data bytes, and knowing that your
> introducing anomalies with any trailing null columns.

Yeah, that's what I'm doing, but I was hoping for some documentation, like the no-longer-documented block header size calculation. If I get the time (HA!), I might just start dumping blocks...

Thanks much!

Received on Thu May 21 2015 - 22:12:10 CEST

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