How to recognize _indextime and _time as values in subseconds ?

Hi Splunkers,

I want to know how does it take for splunk to index the data in subseconds? So I prepared the following configration file.

props.conf

[sampledata]
DATETIME_CONFIG = CURRENT

But in this time, Splunk add timestamps (in this case, system time) in seconds to each events. I know that we cannot use "TIME_FORMAT" option together with "DATETIME_CONFIG = CURRENT". And in default setting, index date (_indextime field) is also in second order.

How can we recognize there fields (_indextime and _time fileds) as values in subsecond order to calculate index time ?

Thank you for your help.