Dynamic defaults for index-time field extraction?

[welchatquietple]

I've a couple of index-time field extractions. In events that are missing one of these fields, is there a way to assign the most recently extracted value for that field from this source/sourcetype? The same behavior I see with timestamp inference, I'd like to be able to have for a non-default field extraction.

[woodcock]

Not really at index time but you can at search time like this:

| streamstats MyFieldAlways=last(MyField) | <your normal search stuff but use "MyFieldAlways" instead of "MyField">