Fast file content searches using IFilters

Last update 2017-01-02

Applies to

PDXpert PLM server software release 6.0 and later.

Using IFilters for indexing library file contents

PDXpert indexes file contents within its Library folder using components of the Microsoft Windows Indexing Service. Immediately after you copy a file into the library, the file contents are scheduled for indexing. Because indexing can take significant computing resources, files are indexed as a low-priority task.

An IFilter is used by the PDXpert Application Server, not the PDXpert client. To be effective, the IFilter must be installed on the computer that hosts the PDXpert Application Server.

You can expand the variety of indexed file types by installing code modules (DLLs) called "IFilters". These are designed to parse files that you've checked into the PDXpert library. In most cases it's very simple to download the IFilters directly from software publishers who define the file type you want indexed or who specialize in developing IFilters.

There are separate IFilter DLLs for 32-bit and 64-bit operating systems. Installing the correct version is essential for indexing.

To find relevant IFilters, search the web for

  • ifilter [name] where [name] is the DLL you want, e.g., ifilter RtfFilt.dll
  • ifilter [type] where [type] is the file type you want, e.g., ifilter dwg
  • ifilter [app] where [app] is the application you want, e.g., ifilter Excel

The quality of IFilters remains unpredictable. Some IFilters are quite good: they parse file contents and properties accurately; support multi-threading; provide speedy results; return useful error diagnostics; and offer adequate technical documentation. Some are, frankly, not so good; for example, for Microsoft Visio files you should use the Office 2007 IFilter instead of the Visio IFilter 2003. If a specific IFilter is slow or inaccurate, contact the publisher to ensure you have their latest.

Standard Windows IFilters

You can view which files will be indexed by opening the Indexing Options utility (Start > Control Panel > Indexing Options, then click Advanced > File Types). Recent versions of Windows XP, Vista, Server 2008 and Windows 7 include general-purpose IFilters. You can verify that your server computer has the following IFilters, which are usually found in C:\Windows\System32 or similar folder:

  • Query.dll plain-text files and files of unregistered origin

  • NlHtml.dll HTML files

  • MimeFilt.dll mail files with the extensions .eml and .nws

  • RtfFilt.dll rich text format (.rtf) files

  • OffFilt.dll Office 97-2003 file types (.doc. .xls, .ppt)

If these IFilters aren't installed, you may accept them through the Windows update service (components related to Windows Search 4.0 or higher).

The Windows TIFF IFilter is a component of Windows 7 and Windows Server 2008 R2. It provides optical character recognition (OCR) on images that conform to the Adobe TIFF Revision 6.0 specification.

Downloadable IFilters

If you have Microsoft Office, the Office IFilter is probably also installed. If you don't have Office installed on your server, you can download and install the IFilter to index these file types: .docx, .docm, .pptx, .pptm, .xlsx, .xlsm, .xlsb, .zip, .one, .vdx, .vsd, .vss, .vst, .vdx, .vsx and .vtx.

If you've installed the Adobe Reader XI on your 32-bit system, then the IFilter for .pdf files is already available. However, you'll require a separate download for 64-bit systems.

A .pdf IFilter is also available from Foxit:

CiTekNet offers a number of IFilters for various files including .cab, .chm, .exe, .rar, and .zip formats.

OpenText has developed a TIFF (.tif) IFilter.

Autodesk offers an IFilter for Autocad DWG files (DWGFilt.dll) and Inventor (INVFilter.dll). These may be available only to licensed Autodesk users via the installer program.

Corel publishes 32b/64b IFilters for their WordPerfect file format.

IFilters for DWG, OpenOffice/StarOffice, RAR, and many others may be found on the IFilterShop website.

The QuiLogic Inc. IFilter indexes files containing XML data.

Ransdell Brown, Inc. publishes an IFilter for DWG files. (Note that the following download site is not the original publisher.)

Other IFilter resources

To examine the IFilters installed on your server and the file types that can be indexed, obtain the IFilter Explorer from CiTekNet:

Technical information about design and implementation of IFilters:


Third-party IFilters and related resources are listed as a convenience, but the listing is not an endorsement of the supplier, product or website. We do not receive compensation for any listing, test these products, nor provide support for any product listed. The IFilters' accuracy, performance, compatibility and licensing are determined exclusively by their publishers. Some IFilters have dependencies and prerequisites that should be verified before installation. We would appreciate learning of any additions or corrections to make this list more useful. Product names on these pages may be trademarks of other companies, and we make no claim to any of them.

This application note was relevant to the PDXpert software release that was current at time of publication. Product changes since that time may affect its utility. We'd be happy to assist you in assessing the applicability of this note to your situation.

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