https://github.com/amplab/spark-indexedrdd

An efficient updatable key-value store for Apache Spark
https://github.com/amplab/spark-indexedrdd

Last synced: 3 months ago
JSON representation

An efficient updatable key-value store for Apache Spark

• Host: GitHub
• URL: https://github.com/amplab/spark-indexedrdd
• Owner: amplab
• License: apache-2.0
• Created: 2014-12-10T23:23:14.000Z (over 9 years ago)
• Default Branch: master
• Last Pushed: 2017-03-11T19:19:30.000Z (over 7 years ago)
• Last Synced: 2024-03-26T08:16:33.774Z (3 months ago)
• Language: Scala
• Size: 101 KB
• Stars: 250
• Watchers: 45
• Forks: 78
• Open Issues: 21
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

Lists

• awesome-spark - Spark Indexedrdd

README

        
# IndexedRDD for Apache Spark

An efficient updatable key-value store for [Apache Spark](http://spark.apache.org).

IndexedRDD extends `RDD[(K, V)]` by enforcing key uniqueness and pre-indexing the entries for efficient joins and point lookups, updates, and deletions. It is implemented by (1) hash-partitioning the entries by key, (2) maintaining a radix tree ([PART](https://github.com/ankurdave/part)) index within each partition, and (3) using this immutable and efficiently updatable data structure to enable efficient modifications and deletions.

## Usage

Add the dependency to your SBT project by adding the following to `build.sbt` (see the [Spark Packages listing](http://spark-packages.org/package/amplab/spark-indexedrdd) for spark-submit and Maven instructions):

```scala

resolvers += "Spark Packages Repo" at "http://dl.bintray.com/spark-packages/maven"

libraryDependencies += "amplab" % "spark-indexedrdd" % "0.3"

```

Then use IndexedRDD as follows:

```scala

import edu.berkeley.cs.amplab.spark.indexedrdd.IndexedRDD

import edu.berkeley.cs.amplab.spark.indexedrdd.IndexedRDD._

// Create an RDD of key-value pairs with Long keys.

val rdd = sc.parallelize((1 to 1000000).map(x => (x.toLong, 0)))

// Construct an IndexedRDD from the pairs, hash-partitioning and indexing

// the entries.

val indexed = IndexedRDD(rdd).cache()

// Perform a point update.

val indexed2 = indexed.put(1234L, 10873).cache()

// Perform a point lookup. Note that the original IndexedRDD remains

// unmodified.

indexed2.get(1234L) // => Some(10873)

indexed.get(1234L) // => Some(0)

// Efficiently join derived IndexedRDD with original.

val indexed3 = indexed.innerJoin(indexed2) { (id, a, b) => b }.filter(_._2 != 0)

indexed3.collect // => Array((1234L, 10873))

// Perform insertions and deletions.

val indexed4 = indexed2.put(-100L, 111).delete(Array(998L, 999L)).cache()

indexed2.get(-100L) // => None

indexed4.get(-100L) // => Some(111)

indexed2.get(999L) // => Some(0)

indexed4.get(999L) // => None

```