On Mon, Jul 16, 2012 at 4:16 PM, Mark Thornton <mthornton@optrak.com> wrote:
>> Actually, it should create a temporary index btree and merge[0] them.
>> Only worth if there are really a lot of rows.
>>
>> [0] http://www.ccs.neu.edu/home/bradrui/index_files/parareorg.pdf
>
> I think 93 million would qualify as a lot of rows. However does any
> available database (commercial or open source) use this optimisation.
Databases, I honestly don't know. But I do know most document
retrieval engines use a similar technique with inverted indexes.
