com.datastax.spark.connector.streaming
StreamingContextFunctions
Related Doc:
package streaming
Returns a view of a Cassandra table as CassandraRDD.
Returns a view of a Cassandra table as CassandraRDD.
This method is made available on SparkContext by importing
com.datastax.spark.connector._
Depending on the type parameter passed to cassandraTable, every row is converted to one of the following:
Example:
CREATE KEYSPACE test WITH replication = {'class': 'SimpleStrategy', 'replication_factor': 1 };
CREATE TABLE test.words (word text PRIMARY KEY, count int);
INSERT INTO test.words (word, count) VALUES ('foo', 20);
INSERT INTO test.words (word, count) VALUES ('bar', 20);
...// Obtaining RDD of CassandraRow objects: val rdd1 = sc.cassandraTable("test", "words") rdd1.first.getString("word") // foo rdd1.first.getInt("count") // 20 // Obtaining RDD of tuples: val rdd2 = sc.cassandraTable[(String, Int)]("test", "words").select("word", "count") rdd2.first._1 // foo rdd2.first._2 // 20 // Obtaining RDD of user defined objects: case class WordCount(word: String, count: Int) val rdd3 = sc.cassandraTable[WordCount]("test", "words") rdd3.first.word // foo rdd3.first.count // 20
Produces the empty CassandraRDD which does not perform any validation and it does not even try to return any rows.
Produces the empty CassandraRDD which does not perform any validation and it does not even try to return any rows.
Provides Cassandra-specific methods on
org.apache.spark.streaming.StreamingContext.