Update Managed Property & Manually Re-Index a SharePoint Library

The SharePoint crawler picks up content that has changed since the last crawl and updates the search index.

When you change a managed property or when you change the mapping of crawled and managed properties then the site must be re-crawled before he changes are reflected in the search index. Since changes are made in the search schema and not to the actual site, the crawler will not automatically re-index. To make sure that the changes are crawled and fully re-indexed, you must request a re-indexing. The site content will be re-crawled and re-indexed so that you can start using the managed properties in queries, query rules and display templates.

In my case I updated several managed property. After the update a re-indexing of the SharePoint library was required for the items to show up in the search.

Mapping the Managed property with the Crawled property

• In the Central Administration go to the Search Service Application.
• Go to Search Schema
• Search for you Managed Property

• Click on property in the search results.
• Make the property Queryable so that this appear in search items
• Click on the "Add a mapping" button and map with the crawled property

[Note: you can do the mapping other way around too.. By searching the crawled property and map the managed property to the crawled property, depending on your scenario]

• Save changes

Re-Indexing the SharePoint library

• Go to the  library settings page of the target SP library.
• Select Advanced settings
• Scroll down and click on the "Reindex Document Library" button
• Click on "Reindex document library" button as shown below

• The re-indexing will happen in the next scheduled crawl.