Hi @alokpaul
Both methods are viable but I think it is best you to decide what the best path for your needs.
Sharegate is a fantastic tool with a huge amount of customisability, if a lot of data remediation and structure changes are needed then I would suggest Sharegate the route to go.
here is the documentation on upgrading to 2019 https://help.nintex.com/en-US/nintex2019/current/sp2019/NW-Upgrade/aa-top-upgradeguide.htm
it is recommended to upgrade first to 2016 from 2013 and then from 2016 to 2019 if you intend to use db migration, I believe there are differences in the data structures between versions that may not be accounted for if you skip versions.
That said I have heard of successful migrations going from 2013 to 2019, I just cannot recommend it.
Hope this helps
Also I have just confirmed the existing instances will move with the db migration they are part of the content dbs.
however it is important to test such migrations extensively.
Hi @alokpaul,
Only when doing a database detach/attach will running workflows continue.
Hi @alokpaul
Did any of these answers solve your question?