Gurjeet Singh skrev: > I missed the ORDER BY clause... Here it goes: > > select t1.id <http://t1.id> as id, t2.id <http://t2.id> as "id+1", > t1.thread as thread, t2.thread as "thread+1", > t1.info <http://t1.info> as info, t2.info <http://t2.info> as > "info+1" > from test as t1, test as t2 > where t2.id <http://t2.id> = ( select min(id) from test as t3 where > t3.id <http://t3.id> > t1.id <http://t1.id> ) > order by t1.id <http://t1.id> asc; > > Also note that this query is much cheaper that the 'distinct on' query > by more than two orders on magnitude ( 217.86 vs. 98040.67): No it isn't. The estimate is much lower, but the actual times are very close: [explain of distinct on] > Time: 5.003 ms [explain of correlated subquery] > Time: 4.125 ms I tried on a larger table (16384 rows), and in this case the numbers are strongly in favor of the subquery. In fact, I am still waiting for the "distinct on" version to return ... /Nis
