Read few parquet files at the same time in Spark

问题

I can read few json-files at the same time using * (star):

sqlContext.jsonFile('/path/to/dir/*.json')

Is there any way to do the same thing for parquet? Star doesn't works.

回答1:

See this issue on the spark jira. It is supported from 1.4 onwards.

Without upgrading to 1.4, you could either point at the top level directory:

sqlContext.parquetFile('/path/to/dir/')

which will load all files in the directory. Alternatively, you could use the HDFS API to find the files you want, and pass them to parquetFile (it accepts varargs).

回答2:

FYI, you can also:

• read subset of parquet files using the wildcard symbol * sqlContext.read.parquet("/path/to/dir/part_*.gz")

• read multiple parquet files by explicitly specifying them sqlContext.read.parquet("/path/to/dir/part_1.gz", "/path/to/dir/part_2.gz")

回答3:

InputPath = [hdfs_path + "parquets/date=18-07-23/hour=2*/*.parquet",
             hdfs_path + "parquets/date=18-07-24/hour=0*/*.parquet"]

df = spark.read.parquet(*InputPath)

回答4:

For Read: Give the file's path and '*'

Example

pqtDF=sqlContext.read.parquet("Path_*.parquet")

来源：https://stackoverflow.com/questions/30421162/read-few-parquet-files-at-the-same-time-in-spark