Hi, (1) do persistent aggregates -- as their name says, they aggregate and persist those aggregates into an external datastore. While (2) do aggregations on streams only, without persisting the resulting aggregates.
Regards, Danijel Schiavuzzi www.schiavuzzi.com On Tue, May 13, 2014 at 9:40 AM, Weide Zhang <[email protected]> wrote: > Hi, > > I'm still confused after I read the storm trident documentation. I sort of > not very clear of 4 functions. especially > > 1. partitionpersist and persistaggregate > 2. partitionaggregate and aggregate > > how these functions are different in nature ? if i specify parrallelhint > for each , what does mean ? > > Thanks, > > Weide > -- Danijel Schiavuzzi E: [email protected] W: www.schiavuzzi.com T: +385989035562 Skype: danijels7
