Alvaro Herrera <alvherre(at)commandprompt(dot)com>, Richard Huxton <dev(at)archonet(dot)com>, Simon Riggs <simon(at)2ndquadrant(dot)com>, Mark Kirkwood <markir(at)paradise(dot)net(dot)nz>, Jeff Davis <pgsql(at)j-davis(dot)com>, postgres hackers <pgsql-hackers(at)postgresql(dot)org>
> Considering that the FK part is unique, the ^^PK^^ > skewness in the relationship is completely determined by the FK part's > histogram. That would give at least a lower/upper bound and MCVs to the > relationship.