I am using ElasticSearch ver. 6.2.3 and I have created three indexes
each of these have common doc type "Subscriber"
All these indexes currently have data which we pushed from 3 SQL databases. Master may or may not have all subscribers details.
If Subscriber is not found under 1st index then it should search under 2 & 3 index.
How can i write query for this? Can i join multiple indexes?