Paver patio inset from rough dug edge?
The rough cut is not dug out to the exact measurement of the finish patio dimension.  So you would not be laying pavers againt the edge of the roughcut.  You still need the space to make laying the last row easy.  After the pavers are laid, you just backfill the roughcut. 

While you do not have to do this. the last row is laid in concrete to lock all the pavers in. Some of the concret is allowed to go up the side of the last row but still beneath the surface.  The other methods is to use commercial paver retainers which uses long spikes to hold the retainer strips in place. This prevents the pavers  over time from creeping outward leaving large gaps.  You would have seen this on older patios where the edge rows become uneven or moved outward where a blocking barrier was not used.