I am working on elasticsearch upgrade from 6.8 to 7.x. i have a date field using format below and i understand that i need to change the mapping to "uuuu-MM-dd HH:mm:ss" before upgrading to elasticsearch 7.8
"type" : "date",
"format" : "yyyy-MM-dd HH:mm:ss"
i have 6 months worth of data in my cluster and i cant wait 6 months to upgrade to 7.x. Do I have to reindex all data with new new mapping enabled? what will happen if i don't reindex data and use new format for the date field going forward. do my searches break?
Thanks for checking.