FAST Search 2010 | Query on Out of the box ContentType Managed Property doesn't return results

  • Article

I was recently working with a customer on FAST Serach Querying and they were using custom search to get results for a specific content type. They were trying to use the OOB Managed Property - ContentType. Somehow it was not returning any results.

As the first step for troubleshooting, I asked them to try whether OOB search works. And that also didnt return any results using the keywords - "ContentType:<NameofContentType>". What was happening.

I checked the central admin Managed property store and found that ContentType Managed property was mapped to the following Crawled properties (In this order)

  • Mime Type
  • Ows_ContentType
  • Basic Text

On the search results page, I changed the xsl to spit out all the properties.

I used the below XSL:

 <?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="https://www.w3.org/1999/XSL/Transform">
<xsl:output method="xml" version="1.0" encoding="UTF-8" indent="yes"/>
<xsl:template match="/">
<xmp><xsl:copy-of select="*"/></xmp>
</xsl:template>
</xsl:stylesheet>

Surprisingly, the Content Type property was showing values like - Text/Html, Application.document, etc. This seemed like MimeType. Now I got it. The Content Type Managed property picks up one of the values from the list of mapped crawled properties and picks the one which comes first. In this case it is MimeType. 
So what you need would be wither changing the OOB property or create a custom managed property and doing a full crawl. Which I did and got the result.

In short in FAST 2010, OOB content Type property doesnt behave the same way as in enterprise search.