Knowledgebase & FAQ

IFilters for RecFind 6


RecFind 6 uses Microsoft's Text Searching Engine included with Microsoft SQL Server for indexing metadata and attachments stored in the RecFind 6 database.

An IFilter is a plugin that allows Microsoft's search engine to index various file formats (such as documents, email attachments, etc.) so that they become searchable. Without an appropriate IFilter, the contents of a file cannot be indexed and able to be searched upon.

A number of file formats are included with SQL Server however additional steps are required to index a number of commonly occurring document formats.

Please note that IFilters are not specific to RecFind 6 nor developed by Knowledgeone Corporation.

To view the attachments currently supported by your Microsoft SQL Server installation, please refer to the 'Viewing supported file extensions' section below.

Viewing supported file extensions

To view the file extensions currently indexed by your SQL Server FullText Search service, run the following command via SQL Management Studio:

SELECT * FROM sys.fulltext_document_types

Enabling operating system iFilters

By default, operating system iFilters are not enabled in SQL Server. To enable, run the following query:

use master
sp_fulltext_service 'load_os_resources', 1
sp_fulltext_service 'verify_signature', 0
reconfigure with override

After running the above queries, restart the Microsoft SQL Server services.

Please refer to the section on 'Viewing supported file extensions' earlier in this article to confirm that additional file extensions are now included.

Recommended IFilters

We have previously recommended installing the Adobe PDF IFilter, this is no longer the case. Newer versions of Microsoft SQL Server/Windows Server now support a number of common file formats automatically, including DOC, DOCX and PDF. The PDF IFilter provided by Microsoft is recommended over the Adobe IFilter as we have found a number of issues with the Adobe IFilter which do not occur with the Microsoft supplied one

As of writing this article, a number of common file extensions are still not included, such as other Microsoft Office file types (e.g. XLSX, PPTX, MSG) and files stored within ZIP files.

Should you wish to add support for these file extensions you will need to download and install the Microsoft Office iFilter and it's service pack on your SQL Server.


After installing new IFilters (or making other changes to your indexing configuration) you will need to rebuild the full-text catalogs. This causes the existing index information to be removed and all records in the database to be re-processed.

To complete a full-text catalog rebuild, click the "Re-Index The Database" option in the DRM. Depending on the number and size of the records in your database, the re-index may take some time to complete. The system will remain operation while the re-index is occurring however the results returned by text searches may be incomplete.

Please note that periodically re-indexing the database is not necessary. The index is automatically maintained when adding, modifying and deleting records.

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