A new SP farm has been setup and the content databases are restored from another farm. All the setup have been made in the search service application but it is not crawling all the documents from the sites even after running full crawl. there is no specific pattern of why the document is not crawled. I edited a document and did check in. Ran an incremental crawl on the corresponding content source. The document is showing up in search. Can anyone please explain why this behavior of SSA occurred and if there is any solution ?