In STREAM mode, the clock may have to have advanced beyond the latest fact so
that certain conditions can be evaluated safely.

For instance, another event could still be inserted at the same millisecond. If
a condition such as
  not Event( this coincides $event )
were evaluated prematurely, it would produce an incorrect result.

Is this the explanation?
-W

On 4 November 2010 10:09, Wolfgang Laun <wolfgang.laun@gmail.com> wrote:
The .drl:

declare Leave
  @role( event )
  @timestamp( timestamp )
end

rule "XXX Leave not !="
when
    $leave: Leave()
    not Leave( this != $leave )
then
    System.out.println( "XXX only one Leave - not !=" );
end

rule "YYY Leave not after"
when
    $leave: Leave()
    not Leave( this before $leave )
then
    System.out.println( "YYY only one Leave - not before" );
end


A) The pseudo-clock is advanced according to the timestamp; then
exactly one event Leave is inserted; then fireAllRules() is called.

1) Running in CLOUD mode, both rules fire.
2) But running in STREAM mode, ONLY rule XXX fires.

B) Like A, but the session clock is advanced by (at least) 1ms
prior to calling fireAllRules().

3) Either mode, both rules fire.

I think that A2) is incorrect; why should passing another msec change the logic?

JIRA?

Wolfgang