ENTRIES TAGGED "Hadoop query"
Shark is 100X faster than Hive for SQL, and 100X faster than Hadoop for machine-learning
Hadoop’s strength is in batch processing, MapReduce isn’t particularly suited for interactive/adhoc queries. Real-time1 SQL queries (on Hadoop data) are usually performed using custom connectors to MPP databases. In practice this means having connectors between separate Hadoop and database clusters. Over the last few months a number of systems that provide fast SQL access within Hadoop clusters have garnered attention. Connectors between Hadoop and fast MPP database clusters are not going away, but there is growing interest in moving many interactive SQL tasks into systems that coexist on the same cluster with Hadoop.
Having a Hadoop cluster support fast/interactive SQL queries dates back a few years to HadoopDB, an open source project out of Yale. The creators of HadoopDB have since started a commercial software company (Hadapt) to build a system that unites Hadoop/MapReduce and SQL. In Hadapt, a (Postgres) database is placed in nodes of a Hadoop cluster, resulting in a system2 that can use MapReduce, SQL, and search (Solr). Now on version 2.0, Hadapt is a fault-tolerant system that comes with analytic functions (HDK) that one can use via SQL. Read more…
Cloudera ventures into real-time queries with Impala, data centers are the new landfill, and Jesper Andersen looks at the relationship between art and data.
Here are a few stories from the data space that caught my attention this week.
Cloudera’s Impala takes Hadoop queries into real-time
Cloudera ventured into real-time Hadoop querying this week, opening up its Impala software platform. As Derrick Harris reports at GigaOm, Impala — an SQL query engine — doesn’t rely on MapReduce, making it faster than tools such as Hive. Cloudera estimates its queries run 10 times faster than Hive, and Charles Zedlewski, Cloudera’s cloud VP of products, told Harris that “small queries can run in less than a second.”
Harris notes that Zedlewski pointed out that Impala wasn’t designed to replace business intelligence (BI) tools, and that “Cloudera isn’t interested in selling BI or other analytic applications.” Rather, Impala serves as the execution engine, still relying on software from Cloudera partners — Zedlewski told Harris, “We’re sticking to our knitting as a platform vendor.”
Joab Jackson at PC World reports that “[e]ventually, Impala will be the basis of a Cloudera commercial offering, called the Cloudera Enterprise RTQ (Real-Time Query), though the company has not specified a release date.”
Impala has plenty of competition on this playing field, which Harris also covers, and he notes the significance of all the recent Hadoop innovation:
“I can’t underscore enough how critical all of this innovation is for Hadoop, which in order to add substance to its unparalleled hype needed to become far more useful to far more users. But the sudden shift from Hadoop as a batch-processing engine built on MapReduce into an ad hoc SQL querying engine might leave industry analysts and even Hadoop users scratching their heads.”
You can read more from Harris’ piece here and Jackson’s piece here. Wired also has an interesting piece on Impala, covering the Google F1 database upon which it is based and the Googler Cloudera hired away to help build it.
(Cloudera CEO Mike Olson discussed Impala, Hadoop and the importance of real-time at this week’s Strata Conference + Hadoop World.)