HDFql – the new HDF tool that speaks SQL

Rick, HDFql team, HDF guest blogger

HDFql (Hierarchical Data Format query language) was recently released to enable users to handle HDF5 files with a language as easy and powerful as SQL. 

By providing a simpler, cleaner, and faster interface for HDF across C/C++/Java/Python/C#, HDFql aims to ease scientific computing, big data management, and real-time analytics. As the author of HDFql, Rick is collaborating with The HDF Group by integrating HDFql with tools such as HDF Compass, while continuously improving HDFql to feed user needs.

Introducing HDFql

HDFqlIf you’re handling HDF files on a regular basis, chances are you’ve had your (un)fair share of programming headaches. Sure, you might have gotten used to the hassle, but navigating the current APIs probably feels a tad like filing expense reports: rarely a complete pleasure!

If you’re new to HDF, you might seek to avoid the format all together. Even trained users have been known to occasionally scout for alternatives.  One doesn’t have to have a limited tolerance for unnecessary complexity to get queasy around these APIs – one simply needs a penchant for clean and simple data management.

This is what we heard from scientists and data veterans when asked about HDF. It’s what challenged our own synapses and inspired us to create HDFql. Because on the flip-side, we also heard something else:

  • HDF has proven immensely valuable in research and science
  • the data format pushes the boundaries on what is achievable with large and complex datasets
  • and it provides an edge on speed and fast access which is critical in the big data / advanced analytics arena

With an aspiration of becoming the de facto language for HDF, we hope that HDFql will play a vital role in the future of HDF data management by:

  • Enabling current users to arrive at (scientific) insights faster via cleaner data handling experiences
  • Inspiring prospective users to adopt the powerful data format HDF by removing current roadblocks
  • Perhaps even grabbing a few HDF challengers or dissenters along the way…

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Whither HDF Java?

Joel Plutchak, The HDF Group

The HDF Group’s support for and use of the Java Programming Language consists of Java wrappers for the HDF4 and HDF5 C libraries, an Object Model definition and implementation, and HDFView, a graphical file viewing application. In this article we’ll discuss what we’re doing now with Java, and look toward the future.

The screen capture shows some of the capabilities of the HDFView application. Being displayed is a JPSS Mission VIIRS (Visible Infrared Imaging Radiometer Suite) Day-Night band dataset in table form and image form with false color palette attached.
The screen capture shows some of the capabilities of the HDFView application.  Displayed is a JPSS Mission VIIRS (Visible Infrared Imaging Radiometer Suite) Day-Night band dataset in table form and image form with false color palette attached.

By the time the first public version of the Java Programming Language was released in 1995, various groups at the University of Illinois were already experimenting with the then-new language.  Among these efforts was a collaboration among several departments; the goal was to produce data browsing tools for use in astronomy and other scientific fields.1  Because The HDF Group was formed to provide access to scientific and engineering data, it seemed natural to extend this early Java work to the display of HDF files and data products.  Continue reading