Solutions - Problem 4ΒΆ
Check if there are any origins in airtraffic data which do not have correpsonding records in airport-codes.
This is an example for outer join.
We need to get those airports which are in Origin field in January 2008 airtraffic data set but not in airport-codes. We need to consider all the valid records from airport codes.
Based on the side of the airtraffic data set, we can say left or right. We will be invoking join using airtraffic data set and hence we will use left outer join.
We will also apply distinct on Origin before performing left outer join.
Let us start spark context for this Notebook so that we can execute the code provided. You can sign up for our 10 node state of the art cluster/labs to learn Spark SQL using our unique integrated LMS.
from pyspark.sql import SparkSession
import getpass
username = getpass.getuser()
spark = SparkSession. \
builder. \
config('spark.ui.port', '0'). \
config("spark.sql.warehouse.dir", f"/user/{username}/warehouse"). \
enableHiveSupport(). \
appName(f'{username} | Python - Joining Data Sets'). \
master('yarn'). \
getOrCreate()
If you are going to use CLIs, you can use Spark SQL using one of the 3 approaches.
Using Spark SQL
spark2-sql \
--master yarn \
--conf spark.ui.port=0 \
--conf spark.sql.warehouse.dir=/user/${USER}/warehouse
Using Scala
spark2-shell \
--master yarn \
--conf spark.ui.port=0 \
--conf spark.sql.warehouse.dir=/user/${USER}/warehouse
Using Pyspark
pyspark2 \
--master yarn \
--conf spark.ui.port=0 \
--conf spark.sql.warehouse.dir=/user/${USER}/warehouse
spark.conf.set("spark.sql.shuffle.partitions", "2")
airtrafficPath = "/public/airtraffic_all/airtraffic-part/flightmonth=200801"
airtraffic = spark. \
read. \
parquet(airtrafficPath)
airtraffic. \
select(
"Year", "Month", "DayOfMonth",
"Origin", "Dest", "CRSDepTime"
). \
show()
+----+-----+----------+------+----+----------+
|Year|Month|DayOfMonth|Origin|Dest|CRSDepTime|
+----+-----+----------+------+----+----------+
|2008| 1| 16| BGR| CVG| 1735|
|2008| 1| 17| SYR| CVG| 1701|
|2008| 1| 17| SAV| BOS| 1225|
|2008| 1| 17| CVG| GRR| 1530|
|2008| 1| 17| STL| CVG| 1205|
|2008| 1| 18| STL| JFK| 1150|
|2008| 1| 18| MCI| CVG| 1009|
|2008| 1| 19| TUL| CVG| 835|
|2008| 1| 20| JFK| PHL| 1935|
|2008| 1| 20| RDU| CVG| 830|
|2008| 1| 21| CVG| DTW| 1640|
|2008| 1| 21| MSY| LGA| 1204|
|2008| 1| 21| JFK| PHL| 1935|
|2008| 1| 21| DCA| JFK| 1830|
|2008| 1| 21| HSV| DCA| 700|
|2008| 1| 22| ORD| CVG| 1910|
|2008| 1| 22| CVG| JFK| 1320|
|2008| 1| 23| LGA| SAV| 908|
|2008| 1| 23| CLT| CVG| 1252|
|2008| 1| 23| GSP| LGA| 635|
+----+-----+----------+------+----+----------+
only showing top 20 rows
airtraffic.count()
605659
airportCodesPath = "/public/airtraffic_all/airport-codes"
def getValidAirportCodes(airportCodesPath):
airportCodes = spark. \
read. \
option("sep", "\t"). \
option("header", True). \
option("inferSchema", True). \
csv(airportCodesPath). \
filter("!(State = 'Hawaii' AND IATA = 'Big')")
return airportCodes
airportCodes = getValidAirportCodes(airportCodesPath)
airportCodes.count()
524
airtraffic. \
select("Origin"). \
distinct(). \
show()
+------+
|Origin|
+------+
| BGR|
| SYR|
| CVG|
| STL|
| JFK|
| MSY|
| DCA|
| HSV|
| ORD|
| CLT|
| GSP|
| BOS|
| COS|
| BNA|
| ATL|
| SJC|
| GJT|
| AZO|
| ELP|
| PDX|
+------+
only showing top 20 rows
airtraffic. \
select("Origin"). \
distinct(). \
count()
286
airtraffic. \
select("Origin"). \
distinct(). \
join(airportCodes, airtraffic["Origin"] == airportCodes["IATA"], "left"). \
show()
+------+----------------+-----+-------+----+
|Origin| City|State|Country|IATA|
+------+----------------+-----+-------+----+
| BGR| Bangor| ME| USA| BGR|
| SYR| Syracuse| NY| USA| SYR|
| CVG| Cincinnati| OH| USA| CVG|
| STL| St. Louis| MO| USA| STL|
| JFK| New York| NY| USA| JFK|
| MSY| New Orleans| LA| USA| MSY|
| DCA| Washington DC| null| USA| DCA|
| HSV| Huntsville| AL| USA| HSV|
| ORD| Chicago| IL| USA| ORD|
| CLT| Charlotte| NC| USA| CLT|
| GSP| Greenville| SC| USA| GSP|
| BOS| Boston| MA| USA| BOS|
| COS|Colorado Springs| CO| USA| COS|
| BNA| Nashville| TN| USA| BNA|
| ATL| Atlanta| GA| USA| ATL|
| SJC| San Jose| CA| USA| SJC|
| GJT| Grand Junction| CO| USA| GJT|
| AZO| Kalamazoo| MI| USA| AZO|
| ELP| El Paso| TX| USA| ELP|
| PDX| Portland| OR| USA| PDX|
+------+----------------+-----+-------+----+
only showing top 20 rows
airtraffic. \
select("Origin"). \
distinct(). \
join(airportCodes, airtraffic["Origin"] == airportCodes["IATA"], "left"). \
filter("IATA IS NULL"). \
show()
+------+----+-----+-------+----+
|Origin|City|State|Country|IATA|
+------+----+-----+-------+----+
| HDN|null| null| null|null|
| SJU|null| null| null|null|
| ITO|null| null| null|null|
| STT|null| null| null|null|
| CEC|null| null| null|null|
| CDC|null| null| null|null|
| PSG|null| null| null|null|
| ADK|null| null| null|null|
| KOA|null| null| null|null|
| OTZ|null| null| null|null|
| BQN|null| null| null|null|
| STX|null| null| null|null|
| PMD|null| null| null|null|
| PSE|null| null| null|null|
| SCC|null| null| null|null|
| SLE|null| null| null|null|
+------+----+-----+-------+----+
airtraffic. \
select("Origin"). \
distinct(). \
join(airportCodes, airtraffic["Origin"] == airportCodes["IATA"], "left"). \
filter("IATA IS NULL"). \
count()
16