Problem when change datatype and index of predicate in Dgraph

Hi everyone,
I have Dgraph Database with huge data (over 10 million nodes). After i change price predicate from string to float (current with over 5 million nodes has price data) and index it, Dgraph server has been freeze and i can’t query or mutate. This is the error:

It seem to be hang forever and can’t excute any query.
I have restart Dgraph service, but still got the problem.
What happen, is it the bug on Dgraph when run with huge data?
Please help me resolve the problem

When you index a predicate Dgraph must finish the generating the index to completion before being able to complete any queries or mutations.

For large data sets you can use bulk loader to create a Dgraph cluster with the updated schema and index.

i think current Dgraph does not resolve problem with huge data. many problem about speed, delay, freeze… i hope it can be more better