streamstats clarification

[echalex]

Hi,

I'm using streamstats to calculate the median for a field and timechart to see the count of events where the field has a value less than a median.

... | streamstats median(bytes) as meby|eval snap=if(bytes>=meby, bytes, "smaller") |timechart count by snap

I just want a clarification whether my assumption is correct. My assumption being that meby will contain the median for all the values of bytes from the entire search. Is my assumption correct?

[Ayn · Accepted solution]

No, streamstats handles calculation of stats in a streaming manner (as is implied by the name). From the docs (http://docs.splunk.com/Documentation/Splunk/latest/SearchReference/Streamstats 😞

The streamstats command, similar to the stats command, calculates summary statistics on search results. Unlike, stats (which works on the results as a whole), streamstats calculates statistics for each event at the time the event is seen.

If you want to calculate stats on all search results, you'll want to use eventstats instead.

[echalex]

Great answer! Thanks!
The reason I needed the clarification was that my results with streamstats happened to coincide with the median of the entire result set. So in this case, the result looks identical to using eventstats, but some further testing highlights the differences.