This becomes much more important when many and nested loops are involved.
The ground state is found as a series of nested loops:
In a traditional nested loop join, will be scanned once for every tuple of .
It is conceptually simple, requiring no nested loops.
The naive algorithm using three nested loops uses communication bandwidth.
We still don't understand the effects on mass-energy conservation, or the intricacies of sequential nested loops.
The transformation and generation systems can typically handle imperfectly nested loops.
The evaluation procedure can be thought of as a nested loop.
Imperfectly nested loops and some transformations (such as tiling) do not fit easily into this framework.
The resulting rows from each side will be shown to a nested loops join operator, sorted, then returned as the result set to the connection.