18 2월 2011

0.15.0 Released

By Shay Banon

elasticsearch version 0.15.0 has just been released. You can download it here. This is another major release that includes several major features and of course, the typical set of bug fixes and enhancements. Some of the major features include:

Versioning

Versioning got its own blog post detailing how to use the feature. It now allows for a more interesting interaction model where we can use optimistic concurrency control when creating and updating documents.

Percolator

Percolator is an interesting feature, basically turning search upside down: Instead of indexing docs and searching for them, during the indexing process docs are “percolated” to find out which queries match them. I can’t wait to see all of the cool things that will be built on top of elasticsearch utilizing this feature!.

Date Histogram

One of the more powerful features of elasticsearch are facets, and one of my favorite facets is the histogram facet (think "number of comments per month). When using it on a date field though, it lacks some important features.

The date_histogram facet comes to solve and enhance the regular histogram by allowing you to “bucket” results by uneven intervals, like months and years.

On top of that, you can provide a time zone to control exactly how the “buckets” of hits are defined – something you can’t really do on the client side.

Search Filter

The new filter element to the search API will now allow you to do facet based navigation in a much simpler way. The new element filters out returned hits, but will not be applied to facet calculations. (although each facet can still have its own filters as well using the facet_filter element).

This allows things like navigation-by-facets to be done in a much simpler manner, while controlling which facets are affected by it and which ones still apply only to the original user-supplied query.

Many More

There are many more performance improvements, enhancements, features, and bug fixes, all listed in the 0.15 download page.

-shay.banon