understand eval vs stats vs max values

[Skwerl23]

i'm trying to grab all items based on a field. the field is a "index" identifier from my data. but i only want the most recent one in my dashboard.

Since eval doesn't have a max function ... e.g.

eval max_value = max(index)  | where index=max_value

is eventstats the only way to do this? These seems like a lot of overhead vs just getting a max value

eventstats max(index) as max_value | where index=max_value

is there another way to do this betteR?

[bowesmana]

eval + max applies to a single field in an event, rather than across all the events. If you have a multivalue field in an event, than max(field) will get the highest value.

To get 'max' across events, if 'index' in your case is numeric, then eventstats + max is appropriate, however, eventstats + latest(index) would be a more general solution if you want the 'latest' value of index based on the time of the event - as @ITWhisperer says, events are normally chronological order, so dedup can work, but it's not always true that it does.

If you're only interested in some fields from the event that has the latest 'index', then you may be able to use stats rather than eventstats, but that will depend on what you're intending to do after this with the results

[ITWhisperer]

Events are usually retrieved in reverse chronological order and dedup keeps the first one it finds so you could try this

| dedup index

[yuanliu]

A solution more efficient than eventstats quite depends on how this index identifier is populated, where it is populated, and how frequently it is populated.  I suspect that this index identifier is not the field index itself as your demo code implies.  Is it?

---

i only want the most recent one in my dashboard.

---

The word "recent" suggests that different indices are populated at different times.  Why is max(index) an effective method to determine which one contains the most recent data?

Because of these conflicting references, it is unclear what you mean by "the most recent one".  Do you mean one index is populated only after another index stopped population? (I.e., no two indices contain overlapping time periods.)  Or do you mean you want the index that contains data that is populated last?