Cloudera Engineering Blog · Hive Posts
Migrating from the Hive CLI to Beeline isn’t as simple as changing the executable name, but this post makes it easy nonetheless.
In its original form, Apache Hive was a heavyweight command-line tool that accepted queries and executed them utilizing MapReduce. Later, the tool split into a client-server model, in which HiveServer1 is the server (responsible for compiling and monitoring MapReduce jobs) and Hive CLI is the command-line interface (sends SQL to the server).
Cloudera provides docs and a sample build environment to help you get easily started writing your own Impala UDFs.
User-defined functions (UDFs) let you code your own application logic for processing column values during a Cloudera Impala query. For example, a UDF could perform calculations using an external math library, combine several column values into one, do geospatial calculations, or other kinds of tests and transformations that are outside the scope of the built-in SQL operators and functions.
Impala’s speed now beats the fastest SQL-on-Hadoop alternatives. Test for yourself!
Since the initial beta release of Cloudera Impala more than one year ago (October 2012), we’ve been committed to regularly updating you about its evolution into the standard for running interactive SQL queries across data in Apache Hadoop and Hadoop-based enterprise data hubs. To briefly recap where we are today:
A quick on-ramp (and demo) for using the new Sentry module for RBAC in conjunction with Hive
One attribute of the Enterprise Data Hub is fine-grained access to data by users and apps. This post about supporting infrastructure for that goal was originally published at blogs.apache.org. We republish it here for your convenience.
The following post was originally published by the Hue Team at the Hue blog in a slightly different form.
Hue, the open source web GUI that makes Apache Hadoop easy to use, has supported Cloudera Impala since its inception to enable fast, interactive SQL queries from within your browser. In this post, you’ll see a demo of Hue’s Impala app in action and explore its impressive query speed for yourself.
Impala App Demo
This installment of the Hue demo series is about accessing the Hive Metastore from Hue, as well as using HCatalog with Hue. (Hue, of course, is the open source Web UI that makes Apache Hadoop easier to use.)
What is HCatalog?
HCatalog is a module in Apache Hive that enables non-Hive scripts to access Hive tables. You can then directly load tables with Apache Pig or MapReduce without having to worry about re-defining the input schemas, or caring about or duplicating the data’s location.
The ecosystem is evolving at a rapid pace – so rapidly, that important developments are often passing through the public attention zone too quickly. Thus, we think it might be helpful to bring you a digest (by no means complete!) of our favorite highlights on a regular basis. (This effort, by the way, has different goals than the fine Hadoop Weekly newsletter, which has a more expansive view – and which you should subscribe to immediately, as far as we’re concerned.)
Find the first installment below. Although the time period reflected here is obviously more than a month long, we have some catching up to do before we can move to a truly monthly cadence.
Every day, more data, users, and applications are accessing ever-larger Apache Hadoop clusters. Although this is good news for data driven organizations overall, for security administrators and compliance officers, there are still lingering questions about how to enable end-users under existing Hadoop infrastructure without compromising security or compliance requirements.
While Hadoop has strong security at the filesystem level, it lacks the granular support needed to adequately secure access to data by users and BI applications. Today, this problem forces organizations in industries for which security is paramount (such as financial services, healthcare, and government) to make a choice: either leave data unprotected or lock out users entirely. Most of the time, the preferred choice is the latter, severely inhibiting access to data in Hadoop.
Editor’s note (added Feb. 2, 2014): You can review the latest (and exciting) Impala performance benchmark results by Cloudera here.
In the presentation below, Scott Leberknight of Near Infinity has done such a good and thorough job of dissecting Cloudera Impala, we want to share it with you here.
Apache Hive was one of the first projects to bring higher-level languages to Apache Hadoop. Specifically, Hive enables the legions of trained SQL users to use industry-standard SQL to process their Hadoop data.
However, as you probably have gathered from all the recent community activity in the SQL-over-Hadoop area, Hive has a few limitations for users in the enterprise space. Until recently, two in particular – concurrency and security – were largely unaddressed.