How can I retain certain field values for all events with tstats when some fields may not exist on all events?

[aboese]

I have an accelerated data model where all events contain a duration field (ReqTot). In addition, some events include a field indicating an experiment that was applied to the given transaction. I want to timechart the exactperc99 of the duration field, grouped by the experiment values. The "no experiment" case is valid and should be represented in the results. However, tstats seems to drop some of the relevant data for events that don't have an experiment field, so I only get results for the experiment cases.

I've tried this several ways, but this is the most straightforward version of the query, as I'd hope it would work.

| tstats exactperc99(sla.ReqTot) from datamodel=Datamodel where (nodename=sla) groupby _time sla.Experiments prestats=true 
| timechart span=5m exactperc99(sla.ReqTot) by sla.Experiments

When I run this query, tstats seems to discard the values of ReqTot for any events where Experiments was not present. As a result, I only see correct results for the experiment cases, but no results at all for the case with no experiment.

If I run in verbose mode I can see that the events still appear to be present, but they don't have values for ReqTot. A similar query that determines a count by Experiments value produces correct results, because the value of ReqTot doesn't matter. And if I remove Experiments from the groupby clause, I get a correct result for all events; in verbose mode, all events show a proper histogram of values for ReqTot. The inclusion of the missing field seems to cause the values of all other fields to be excluded.

Why is tstats discarding my data, and is there any way to make this query work correctly?

[datatracker14]

Use

fillnull value=NULL Field_1 Field_2 ..

for the fields you want to fix the null problem

[datatracker14]

use
fillnull value=NULL Field_1 Field_2 ..

for the field list you want to address

[aboese]

I can't explain it, but the original query now seems to work as expected. I wasn't necessarily surprised at the original results, as I am under the impression that stats (and possibly tstats) do throw out null split by values. That doesn't seem to be the case here, as I'm not having to do anything to fill my null values. As a result, I'd still be interested in any information anyone else has on what the expected behavior would be.