Deepak j-thepac

Indexes to query data faster, speed up sort operation, and enforce unique constraints.
A DB table each row has rowid and sequence number to identify row
Eg :table = list of pairs (rowid, row) )
Index is created on a seperate table which has opposite relationship: (row, rowid)
SQLite uses B-tree ie., balanced-tree ie., Actual table rows = Index table rows

Mac:

Create xml file .../spark-3.0.0-bin-hadoop2.7/conf/hive-site.xml

<configuration> 
    <property> 
      <name>hive.metastore.warehouse.dir</name> 
      <value>/Users/deepakjayaprakash/Downloads/spark_database/</value> 
    </property> 
  </configuration>

Save

Principles

Loose Coupling
High Cohesion
Change is Local
It is Easy to Remove

Smells

Rigidity ( A -> B -> C . something hardcoded in C )
Fragility
Immobility

postgres-Django

Ref:Tutorial

Azure App Service

Creat APP

    git clone https://github.com/Azure-Samples/djangoapp
    cd djangoapp
    az webapp up \

--resource-group DjangoPostgres-tutorial-rg \

	package ch06
	import org.apache.spark.sql.SparkSession
	import org.apache.spark.sql.functions.lit
	import org.apache.spark.sql.types.StringType
	//nc -l -p 9999
	object SimpleStream extends App {

	val spark = SparkSession.builder
	.master("local")
	.appName("StructuredNetworkWordCount")

	import org.apache.spark.{SparkConf, SparkContext}
	import org.apache.spark.streaming.{Seconds, StreamingContext}
	import org.apache.spark.streaming.dstream.DStream
	//nc -l -p 9999
	object DStreamSoacket extends App {
	val conf = new SparkConf().setMaster("local[*]").setAppName("App name")
	val sc = new SparkContext(conf)
	val ssc = new StreamingContext(sc, Seconds(5))
	val lines: DStream[String] = ssc.socketTextStream(hostname = "localhost", port = 9999)
	val wordCounts = lines.flatMap(_.split(" ")).map(word => (word, 1)).reduceByKey(_ + _)

	import org.apache.spark._
	import org.apache.spark.streaming._
	import org.apache.spark.streaming.dstream.DStream
	object DStreamSimpleText extends App {
	val conf = new SparkConf().setMaster("local[*]").setAppName("App name")
	val sc = new SparkContext(conf)
	val ssc = new StreamingContext(sc, Seconds(5))
	val filestream: DStream[String] = ssc.textFileStream(
	"/Users/deepakjayaprakash/Downloads/testing"
	) // read new file


	import org.apache.spark.rdd.RDD
	import org.apache.spark.{SparkConf}
	import org.apache.spark.streaming.{Seconds, StreamingContext}

	object DStreamSendRDD extends App {
	val conf = new SparkConf().setMaster("local[*]").setAppName("StreamingTransformExample")
	val ssc = new StreamingContext(conf, Seconds(5))
	val rdd1 = ssc.sparkContext.parallelize(Array(1, 2, 3))
	val rddQueue = scala.collection.mutable.Queue[RDD[Int]]() //scala.collection.mutable.Queue[RDD[MyObject]]()

	import org.apache.spark.sql.SparkSession

	object SimpleStream extends App {

	val spark = SparkSession.builder
	.master("local")
	.appName("StructuredNetworkWordCount")
	.getOrCreate()
	spark.sparkContext.setLogLevel("ERROR")

	// Ref -https://sttp.softwaremill.com/en/latest/examples.html

	/*
	libraryDependencies += "com.softwaremill.sttp.client3" %% "core" % "3.5.1"

	Bazel Dependencies :
	com.softwaremill.sttp.client3.core
	com.softwaremill.sttp.client3.model
	com.softwaremill.sttp.client3.shared
	*/