>
> I modify the tech query5 to DataFrame:
> val forders =
> spark.read.parquet("hdfs://dell127:20500/SparkParquetDoubleTimestamp100G/orders
>
> <hdfs://dell127:20500/SparkParquetDoubleTimestamp100G/orders>”).filter("o_orderdate
> < 1995-01-01 and o_orderdate >= 1994-01-01").select("o_custkey",
> "o_orderkey")
> val flineitem =
> spark.read.parquet("hdfs://dell127:20500/SparkParquetDoubleTimestamp100G/lineitem
> <hdfs://dell127:20500/SparkParquetDoubleTimestamp100G/lineitem>")
> val fcustomer =
> spark.read.parquet("hdfs://dell127:20500/SparkParquetDoubleTimestamp100G/customer
> <hdfs://dell127:20500/SparkParquetDoubleTimestamp100G/customer>")
> val fsupplier =
> spark.read.parquet("hdfs://dell127:20500/SparkParquetDoubleTimestamp100G/supplier
> <hdfs://dell127:20500/SparkParquetDoubleTimestamp100G/supplier>")
> val fregion =
> spark.read.parquet("hdfs://dell127:20500/SparkParquetDoubleTimestamp100G/region
>
> <hdfs://dell127:20500/SparkParquetDoubleTimestamp100G/region>”).where("r_name
> = 'ASIA'").select($"r_regionkey")
> val fnation =
> spark.read.parquet("hdfs://dell127:20500/SparkParquetDoubleTimestamp100G/nation
> <hdfs://dell127:20500/SparkParquetDoubleTimestamp100G/nation>”)
> val decrease = udf { (x: Double, y: Double) => x * (1 - y) }
> val res = flineitem.join(forders, $"l_orderkey" === forders("o_orderkey"))
> .join(fcustomer, $"o_custkey" === fcustomer("c_custkey"))
> .join(fsupplier, $"l_suppkey" === fsupplier("s_suppkey") &&
> $"c_nationkey" === fsupplier("s_nationkey"))
> .join(fnation, $"s_nationkey" === fnation("n_nationkey"))
> .join(fregion, $"n_regionkey" === fregion("r_regionkey"))
> .select($"n_name", decrease($"l_extendedprice",
> $"l_discount").as("value"))
> .groupBy($"n_name")
> .agg(sum($"value").as("revenue"))
> .sort($"revenue".desc).show()
>
> My environment is one master(Hdfs-namenode), four workers(HDFS-datanode),
> each with 40 cores and 128GB memory. TPCH 100G, stored data on hdfs with
> parquet format.
> It executed about 1.5m, I found that read these 6 tables using
> spark.read.parqeut is sequential, How can I made this to run parallelly ?
> I’ve already set data locality and spark.default.parallelism,
> spark.serializer, using G1, But the runtime is still not reduced.
> And is there any advices for me to tuning this performance?
> Thank you.
Wenting He.