good point. But when you use a LIMIT in a SELECT statement you WANT n RANDOM tuples - its wrong to get RANDOM tuples ? So, in the same logic, its wrong to exclude n random tuples ? Besides, if you want DELETE just 1 tuple, why the executor have to scan the entire table, and not just stoping after find the 1 tuple ? Why the LIMIT clause should be used to speedup only SELECT statements ? if the programmer know the expected number of affected rows why not use it to speed up DELETE/UPDATE ?
cheers, -- Daniel Loureiro http://diffcoder.blogspot.com/ 2010/11/30 Jaime Casanova <ja...@2ndquadrant.com> > On Mon, Nov 29, 2010 at 9:08 PM, Daniel Loureiro <loureir...@gmail.com> > wrote: > > > > 3) change the executor to stop after “n” successful iterations. Is > > this correct ? > > > > no. it means you will delete the n first tuples that happen to be > found, if you don't have a WHERE clause that means is very possible > you delete something you don't want to... the correct solution is to > use always try DELETE's inside transactions and only if you see the > right thing happening issue a COMMIT > > besides i think this has been proposed and rejected before > > -- > Jaime Casanova www.2ndQuadrant.com > Professional PostgreSQL: Soporte y capacitación de PostgreSQL >
