How can I write parquet file with min/max statistic?
2018-01-24 10:30 GMT+09:00 Stephen Joung <step...@vcnc.co.kr>:
> Hi, I am trying to use spark sql filter push down. and specially want to
> use row group skipping with parquet file.
>
> And I guessed that I need parquet file with statistics min/max.
>
> ----
>
> On spark master branch - I tried to write single column with "a", "b", "c"
> to parquet file f1
>
> scala> List("a", "b", "c").toDF("field1").coalesce(
> 1).write.parquet("f1")
>
> But saved file does not have statistics (min, max)
>
> $ ls f1/*.parquet
> f1/part-00000-445036f9-7a40-4333-8405-8451faa44319-c000.snappy.parquet
> $ parquet-tool meta f1/*.parquet
> file:
> file:/Users/stephen/p/spark/f1/part-00000-445036f9-7a40-4333-8405-8451faa44319-
> c000.snappy.parquet
> creator: parquet-mr version 1.8.2 (build
> c6522788629e590a53eb79874b95f6c3ff11f16c)
> extra: org.apache.spark.sql.parquet.row.metadata =
> {"type":"struct","fields":[{"name":"field1","type":"string"
> ,"nullable":true,"metadata":{}}]}
>
> file schema: spark_schema
> -----------------------------------------------------------
> ---------------------
> field1: OPTIONAL BINARY O:UTF8 R:0 D:1
>
> row group 1: RC:3 TS:48 OFFSET:4
> -----------------------------------------------------------
> ---------------------
> field1: BINARY SNAPPY DO:0 FPO:4 SZ:50/48/0.96 VC:3
> ENC:BIT_PACKED,RLE,PLAIN ST:[no stats for this column]
>
> ----
>
> Any pointer or comment would be appreciated.
> Thank you.
>
>
