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  1. Spark
  2. SPARK-31404 file source backward compatibility after calendar switch
  3. SPARK-31672

Reading wrong timestamps from dictionary encoded columns in Parquet files

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    Details

    • Type: Sub-task
    • Status: Resolved
    • Priority: Major
    • Resolution: Fixed
    • Affects Version/s: 3.0.0, 3.1.0
    • Fix Version/s: 3.0.0
    • Component/s: SQL
    • Labels:
      None

      Description

      Write dates with dictionary encoding enabled to parquet files:

      Welcome to
            ____              __
           / __/__  ___ _____/ /__
          _\ \/ _ \/ _ `/ __/  '_/
         /___/ .__/\_,_/_/ /_/\_\   version 3.1.0-SNAPSHOT
            /_/
      
      Using Scala version 2.12.10 (OpenJDK 64-Bit Server VM, Java 1.8.0_242)
      Type in expressions to have them evaluated.
      Type :help for more information.
      
      scala> spark.conf.set("spark.sql.legacy.parquet.rebaseDateTimeInWrite.enabled", true)
      scala> spark.conf.set("spark.sql.parquet.outputTimestampType", "TIMESTAMP_MICROS")
      
      scala> :paste
      // Entering paste mode (ctrl-D to finish)
      
                      Seq.tabulate(8)(_ => "1001-01-01 01:02:03.123").toDF("tsS")
                        .select($"tsS".cast("timestamp").as("ts"))
                        .repartition(1)
                        .write
                        .option("parquet.enable.dictionary", true)
                        .mode("overwrite")
                        .parquet("/Users/maximgekk/tmp/parquet-ts-dict")
      
      // Exiting paste mode, now interpreting.
      

      Read them back:

      scala> spark.read.parquet("/Users/maximgekk/tmp/parquet-ts-dict").show(false)
      +-----------------------+
      |ts                     |
      +-----------------------+
      |1001-01-07 00:32:20.123|
      |1001-01-07 00:32:20.123|
      |1001-01-07 00:32:20.123|
      |1001-01-07 00:32:20.123|
      |1001-01-07 00:32:20.123|
      |1001-01-07 00:32:20.123|
      |1001-01-07 00:32:20.123|
      |1001-01-07 00:32:20.123|
      +-----------------------+
      

      Expected values must be 1001-01-01 01:02:03.123.

      I checked that the timestamp column is encoded by dictionary via:

      ➜  parquet-ts-dict java -jar ~/Downloads/parquet-tools-1.12.0.jar dump ./part-00000-2c6c89b1-d165-4528-9a9d-796baa07908e-c000.snappy.parquet
      row group 0
      --------------------------------------------------------------------------------
      ts:  INT64 SNAPPY DO:0 FPO:4 SZ:94/90/0.96 VC:8 ENC:BIT_PACKED,RLE,PLA [more]...
      
          ts TV=8 RL=0 DL=1 DS: 1 DE:PLAIN_DICTIONARY
          ----------------------------------------------------------------------------
          page 0:                DLE:RLE RLE:BIT_PACKED VLE:PLAIN_DICTIONARY [more]... VC:8
      
      INT64 ts
      --------------------------------------------------------------------------------
      *** row group 1 of 1, values 1 to 8 ***
      value 1: R:0 D:1 V:1001-01-06T22:02:03.123000+0000
      value 2: R:0 D:1 V:1001-01-06T22:02:03.123000+0000
      value 3: R:0 D:1 V:1001-01-06T22:02:03.123000+0000
      value 4: R:0 D:1 V:1001-01-06T22:02:03.123000+0000
      value 5: R:0 D:1 V:1001-01-06T22:02:03.123000+0000
      value 6: R:0 D:1 V:1001-01-06T22:02:03.123000+0000
      value 7: R:0 D:1 V:1001-01-06T22:02:03.123000+0000
      value 8: R:0 D:1 V:1001-01-06T22:02:03.123000+0000
      

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              • Assignee:
                maxgekk Max Gekk
                Reporter:
                maxgekk Max Gekk
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                • Created:
                  Updated:
                  Resolved: