Bozhidar Karaargirov created SPARK-30926:
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Summary: Same SQL on CSV and on Parquet gives different result
Key: SPARK-30926
URL: https://issues.apache.org/jira/browse/SPARK-30926
Project: Spark
Issue Type: Bug
Components: SQL
Affects Versions: 2.4.4
Environment: I run this locally on a windows 10 machine.
The java runtime is:
{color:#cccccc}openjdk 11.0.5 2019-10-15
OpenJDK Runtime Environment AdoptOpenJDK (build 11.0.5+10)
OpenJDK 64-Bit Server VM AdoptOpenJDK (build 11.0.5+10, mixed mode){color}
Reporter: Bozhidar Karaargirov
SO I played around with a data set from here:
[https://www.kaggle.com/hmavrodiev/sofia-air-quality-dataset]
I ran the same query for the base CSVs and against a parquet version of them:
{color:#008000}SELECT * FROM airQualityP WHERE P1 > 20{color}
Here is the csv code:
{color:#000080}import
{color}{color:#660e7a}session{color}.{color:#660e7a}sqlContext{color}.implicits._
{color:#000080}val {color}df =
{color:#660e7a}session{color}.read.option({color:#008000}"header"{color},
{color:#008000}"true"{color}).csv({color:#660e7a}originalDataset{color})
df.createTempView({color:#008000}"airQuality"{color})
{color:#000080}val {color}result =
{color:#660e7a}session{color}.sql({color:#008000}"SELECT * FROM airQuality
WHERE P1 > 20"{color})
.map(ParticleAirQuality.{color:#660e7a}mappingFunction{color})
println(result.count())
Here is the parquet code:
{color:#000080}import
{color}{color:#660e7a}session{color}.{color:#660e7a}sqlContext{color}.implicits._
{color:#000080}val {color}df =
{color:#660e7a}session{color}.read.option({color:#008000}"header"{color},
{color:#008000}"true"{color}).parquet({color:#660e7a}bigParquetDataset{color})
df.createTempView({color:#008000}"airQualityP"{color})
{color:#000080}val {color}result = {color:#660e7a}session
{color} .sql({color:#008000}"SELECT * FROM airQualityP WHERE P1 > 20"{color})
.map(ParticleAirQuality.{color:#660e7a}namedMappingFunction{color})
println(result.count())
And this is how I transform the csv into parquets:
{color:#000080}import
{color}{color:#660e7a}session{color}.{color:#660e7a}sqlContext{color}.implicits._
{color:#000080}val {color}df =
{color:#660e7a}session{color}.read.option({color:#008000}"header"{color},
{color:#008000}"true"{color})
.csv({color:#660e7a}originalDataset{color})
.map(ParticleAirQuality.{color:#660e7a}mappingFunction{color})
df.write.parquet({color:#660e7a}bigParquetDataset{color})
These are the two mapping functions:
{color:#000080}val {color}{color:#660e7a}mappingFunction {color}= {
r: Row => ParticleAirQuality(
r.getString({color:#0000ff}1{color}),
r.getString({color:#0000ff}2{color}),
r.getString({color:#0000ff}3{color}),
r.getString({color:#0000ff}4{color}),
r.getString({color:#0000ff}5{color}),
{
{color:#000080}val {color}p1 = r.getString({color:#0000ff}6{color})
{color:#000080}if{color}(p1 == {color:#000080}null{color})
Double.{color:#660e7a}NaN
{color} {color:#000080}else {color}p1.toDouble
},
{
{color:#000080}val {color}p2 = r.getString({color:#0000ff}7{color})
{color:#000080}if{color}(p2 == {color:#000080}null{color})
Double.{color:#660e7a}NaN
{color} {color:#000080}else {color}p2.toDouble
}
) }
{color:#000080}val {color}{color:#660e7a}namedMappingFunction {color}= {
r: Row => ParticleAirQuality(
r.getAs[{color:#20999d}String{color}]({color:#008000}"sensor_id"{color}),
r.getAs[{color:#20999d}String{color}]({color:#008000}"location"{color}),
r.getAs[{color:#20999d}String{color}]({color:#008000}"lat"{color}),
r.getAs[{color:#20999d}String{color}]({color:#008000}"lon"{color}),
r.getAs[{color:#20999d}String{color}]({color:#008000}"timestamp"{color}),
r.getAs[Double]({color:#008000}"P1"{color}),
r.getAs[Double]({color:#008000}"P2"{color})
)
}
If it matters this is the paths:
{color:#000080}val {color}{color:#660e7a}originalDataset {color}=
{color:#008000}"D:{color}{color:#000080}\\{color}{color:#008000}source{color}{color:#000080}\\{color}{color:#008000}datasets{color}{color:#000080}\\{color}{color:#008000}sofia-air-quality-dataset{color}{color:#000080}\\{color}{color:#008000}*sds*.csv"
{color}{color:#000080}val {color}{color:#660e7a}bigParquetDataset {color}=
{color:#008000}"D:{color}{color:#000080}\\{color}{color:#008000}source{color}{color:#000080}\\{color}{color:#008000}datasets{color}{color:#000080}\\{color}{color:#008000}air-tests{color}{color:#000080}\\{color}{color:#008000}all-parquet"{color}
The count from the csvs I get is: 33934609
While the count from the parquets is: 35739394
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