Help Post(Urgent):Not able to perform Sum in theMetric Field in Grafana v7.1.5

Hi ,

Recently I have migrated to grafana 7.0+ .The same query I used to run previously is not running now.
The issue is regrading to perform sum on one of my field.
The previous setup that worked fine:

After Upgrade:

After upgrade I tried below but got error as “Text fields are not optimised for operations that require per-document field data like aggregations and sorting, so these operations are disabled by default. Please use a keyword field instead. Alternatively, set fielddata=true on [totrec] in order to load field data by uninverting the inverted index. Note that this can use significant memory.” So I set it as true but then I am getting error as “Field [totrec.keyword] of type [keyword(indexed,omitNorms,indexOptions=DOCS)] is not supported for aggregation

Could anyone help me please