Re: Query cost

On Monday, November 11, 2013 12:40:01 PM UTC, Alexander Langer wrote:
> Am 08.11.2013 16:33, schrieb :
>
> > Divison is not a primitive operation; It is implemented using a equivalent RA expression
>
> > ΠR−S((ΠR−S(r)×s)−ΠR−S,S(r))
>
>
>
> Explain the operator Π - is it projection ?
>
>
>
> In general it depends on implementation of the operations.
>
> You know the big O Notation ?

yes it is projection (sorry about the font!) I just wanted a simple approach; like for join br+br*bs using block nested loop join (b=number of blocks) Does it use sort merge or hash functions cause there is set difference? Received on Mon Nov 11 2013 - 13:53:30 CET