Tom Lane wrote: > [EMAIL PROTECTED] (Bruce Momjian) writes: > > Re-add item with better description: > > >> * Allow ORDER BY ... LIMIT 1 to select high/low value without sort or > >> index using a sequential scan for highest/lowest values > >> > >> Right now, if no index exists, ORDER BY ... LIMIT 1 requires we sort > >> all values to return the high/low value. Instead The idea is to do a > >> sequential scan to find the high/low value, thus avoiding the sort. > > That's not much better, as it simply begs the question "why not use > MIN/MAX"?
> I think the real point of Oleg's suggestion is a better way to do "top N" > queries. This does not get interesting unless N > 1. Good point, updated: * Allow ORDER BY ... LIMIT # to select high/low value without sort or index using a sequential scan for highest/lowest values Right now, if no index exists, ORDER BY ... LIMIT # requires we sort all values to return the high/low value. Instead The idea is to do a sequential scan to find the high/low value, thus avoiding the sort. MIN/MAX already does this, but not for LIMIT > 1. -- Bruce Momjian | http://candle.pha.pa.us [email protected] | (610) 359-1001 + If your life is a hard drive, | 13 Roberts Road + Christ can be your backup. | Newtown Square, Pennsylvania 19073 ---------------------------(end of broadcast)--------------------------- TIP 2: you can get off all lists at once with the unregister command (send "unregister YourEmailAddressHere" to [EMAIL PROTECTED])
