RE: Where is IBM?

["Walden H. Leverich III" <WaldenL@xxxxxxxxxxxxxxx>]

>See, SQL Server breaks its queries up into chunks 
>based on the maximum memory in the system

Now we're getting into a discussion of query optimizer design. I'm sure we
can agree that _both_ Microsoft and IBM have experts that are _MUCH_ more
versed in how this works than you or I. 

However, I would expect that both systems evaluate the where clause, open
the index, lookup the keyvalue in the index, get the offset into the
dataspace and then get the row from that offset. Simple enough.

The index appears to store offsets into the dataspace, not addresses of the
rows. (Follow the pointer trail in SST from File->Member->QDSSI row offsets
around x2000 and key vales around x3FF0 working backwards) 

This also makes sense since we can save and restore access paths. If the
address of the rows was stored they would be meaningless on a restore. So,
Single-Level store or not, a database is just a byte stream.

-Walden

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Walden H Leverich III
President
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