When working out the storage requirements on a per-row basis, how is the size of the NULL bitmap determined?
I know that there are CEILING(n / 8) bytes of NULL bitmap per n columns - but what I don't know is whether there are always two column count bytes or not.
CEILING(n / 8)
Can anyone confirm / deny?
Apr 21, 2011 at 02:04 AM
Matt Whitfield ♦♦
I'm sure Klaus covered this in his talk at SQLBits... but I can't remember
According the MSDN, there are the 2 bytes alwas: Null_Bitmap = 2 + ((Num_Cols + 7) / 8)
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Apr 21, 2011 at 02:47 AM
Awesome, cheers - was clearly having an information finding fail day :)
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asked: Apr 21, 2011 at 02:04 AM
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