How can I avoid getting error "Events may not be returned in sub-second order due to search memory limits configured in limits.conf:[search]:max_rawsize_perchunk"?

Hi, I have got below error message Events may not be returned in sub-second order due to search memory limits configured in limits.conf:[search]:max_rawsize_perchunk. See search.log for more information. I have uploaded data into summary index as one batch. I think this caused the issue because _time is as uploaded date. How can I avoid this error message? What can I change in conf files? thanks