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https://issues.apache.org/jira/browse/PARQUET-1883?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17215801#comment-17215801
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ASF GitHub Bot commented on PARQUET-1883:
-----------------------------------------
anantdamle commented on pull request #821:
URL: https://github.com/apache/parquet-mr/pull/821#issuecomment-710758060
Hi team,
How should I proceed? We have many old Parquet files still using INT96, this
patch will at least help in reading those files using ParquertIO.readers in
Apache Beam.
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> int96 support in parquet-avro
> -----------------------------
>
> Key: PARQUET-1883
> URL: https://issues.apache.org/jira/browse/PARQUET-1883
> Project: Parquet
> Issue Type: Bug
> Components: parquet-avro
> Affects Versions: 1.10.1
> Reporter: satish
> Priority: Major
>
> Hi
> It looks like 'timestamp' is being converted to 'int64' primitive type in
> parquet-avro. This is incompatible with hive2. Hive throws below error
> {code:java}
> Error: java.io.IOException: org.apache.hadoop.hive.ql.metadata.HiveException:
> java.lang.ClassCastException: org.apache.hadoop.io.LongWritable cannot be
> cast to org.apache.hadoop.hive.serde2.io.TimestampWritable (state=,code=0)
> {code}
> What does it take to write timestamp field as 'int96'?
> Hive seems to write timestamp field as int96. See example below
> {code:java}
> $ hadoop jar parquet-tools-1.9.0.jar meta hdfs://timestamp_test/000000_0
> creator: parquet-mr version 1.10.6 (build
> 098c6199a821edd3d6af56b962fd0f1558af849b)
> file schema: hive_schema
> --------------------------------------------------------------------------------
> ts: OPTIONAL INT96 R:0 D:1
> row group 1: RC:4 TS:88 OFFSET:4
> --------------------------------------------------------------------------------
> ts: INT96 UNCOMPRESSED DO:0 FPO:4 SZ:88/88/1.00 VC:4
> ENC:BIT_PACKED,RLE,PLAIN_DICTIONARY
> {code}
> Writing a spark dataframe into parquet format (without using avro) is also
> using int96.
> {code:java}
> scala> testDS.printSchema()
> root
> |-- ts: timestamp (nullable = true)
> scala> testDS.write.mode(Overwrite).save("/tmp/x");
> $ parquet-tools meta
> /tmp/x/part-00000-99720ebd-0aea-45ac-9b8c-0eb7ad6f4e3c-c000.gz.parquet
> file:
> file:/tmp/x/part-00000-99720ebd-0aea-45ac-9b8c-0eb7ad6f4e3c-c000.gz.parquet
> creator: parquet-mr version 1.10.1 (build
> a89df8f9932b6ef6633d06069e50c9b7970bebd1)
> extra: org.apache.spark.sql.parquet.row.metadata =
> {"type":"struct","fields":[{"name":"ts","type":"timestamp","nullable":true,"metadata":{}}]}
>
> file schema: spark_schema
> --------------------------------------------------------------------------------
> ts: OPTIONAL INT96 R:0 D:1
> row group 1: RC:4 TS:93 OFFSET:4
> --------------------------------------------------------------------------------
> ts: INT96 GZIP DO:0 FPO:4 SZ:130/93/0.72 VC:4
> ENC:RLE,PLAIN_DICTIONARY,BIT_PACKED ST:[no stats for this column]
> {code}
> I saw some explanation for deprecating int96 [support
> here|https://issues.apache.org/jira/browse/PARQUET-1870?focusedCommentId=17127963&page=com.atlassian.jira.plugin.system.issuetabpanels%3Acomment-tabpanel#comment-17127963]
> from [~gszadovszky]. But given hive and serialization in other parquet
> modules (non-avro) support int96, I'm trying to understand the reasoning for
> not implementing it in parquet-avro.
> A bit more context: we are trying to migrate some of our data to [hudi
> format|https://hudi.apache.org/]. Hudi adds a lot of efficiency for our use
> cases. But, when we write data using hudi, hudi uses parquet-avro and
> timestamp is being converted to int64. As mentioned earlier, this breaks
> compatibility with hive. A lot of columns in our tables have 'timestamp' as
> type in hive DDL. It is almost impossible to change DDL to long as there are
> large number of tables and columns.
> We are happy to contribute if there is a clear path forward to support int96
> in parquet-avro. Please also let me know if you are aware of a workaround in
> hive that can read int64 correctly as timestamp.
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