I have 10 search definition of exact similar schema in Vespa, I want to merge (union) them all.
Example-
I have search_definition_1.sd
I have search_definition_2.sd
I have search_definition_3.sd
.
.
.
I have search_defination_10.sd
Now I need to search from all of the search definition at once, is it possible to union them all and create new search_definition_1_to_10.sd or search in all of at once.
Vespa will by default query all schemas (document types), so supported out of the box. For more fine-grained control, see https://docs.vespa.ai/documentation/federation.html
I did not get what you mean by 10 exact similar schemas, though, there should be no need to have identical schemas.
Unless you use the restrict parameter to restrict to a document type Vespa federates and searches all document types in a content cluster and merges the hits by relevancy score. See end of this document https://docs.vespa.ai/documentation/schemas.html#querying-multiple-document-types and https://docs.vespa.ai/documentation/reference/query-api-reference.html#model.restrict