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https://issues.apache.org/jira/browse/DRILL-4763?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Arina Ielchiieva resolved DRILL-4763.
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Resolution: Duplicate
Merged into master with three commits with Jira DRILL-4203:
2f4b5ef717ed78a1ebb65687af9688a902e02041
ae34d5c30582de777db19360abf013bc50c8640b
8461d10b4fd6ce56361d1d826bb3a38b6dc8473c
> Parquet file with DATE logical type produces wrong results for simple SELECT
> ----------------------------------------------------------------------------
>
> Key: DRILL-4763
> URL: https://issues.apache.org/jira/browse/DRILL-4763
> Project: Apache Drill
> Issue Type: Bug
> Components: Execution - Data Types
> Affects Versions: 1.6.0
> Reporter: Paul Rogers
> Assignee: Vitalii Diravka
> Fix For: 1.9.0
>
> Attachments: date.parquet, int_16.parquet
>
>
> Created a simple Parquet file with the following schema:
> message test { required int32 index; required int32 value (DATE); required
> int32 raw; }
> That is, a file with an int32 storage type and a DATE logical type. Then,
> created a number of test values:
> 0 (which should be interpreted as 1970-01-01) and
> (int) (System.currentTimeMillis() / (24*60*60*1000) ) Which should be
> interpreted as the number of days since 1970-01-01 and today.
> According to the Parquet spec
> (https://github.com/Parquet/parquet-format/blob/master/LogicalTypes.md),
> Parquet dates are expressed as "the number of days from the Unix epoch, 1
> January 1970."
> Java timestamps are expressed as "measured in milliseconds, between the
> current time and midnight, January 1, 1970 UTC."
> There is ambiguity here: Parquet dates are presumably local times not
> absolute times, so the math above will actually tell us the date in London
> right now, but that's close enough.
> Generate the local file to date.parquet. Query it with:
> SELECT * from `local`.`root`.`date.parquet`;
> The results are incorrect:
> index value raw
> 1 -11395-10-18T00:00:00.000-07:52:58 0
> Here, we have a value of 0. The displayed date is decidedly not
> 1970-01-01T00:00:00. We actually have many problems:
> 1. The date is far off.
> 2. The output shows time. But, the Parquet DATE format explcitly does NOT
> include time, so it makes no sense to include it.
> 3. The output attempts to show a time zone, but a time zone of -07:52:58,
> while close to PST, is not right (there is no timezine that is of by 7:02
> from UTC.)
> 4. The data has no time zone, Parquet DATE explicilty is a local time, so it
> is impossible to know the relationship between that date an UTC.
> The correct output (in ISO format) would be: 1970-01-01
> The last line should be today's date, but instead is:
> 6 -11348-04-20T00:00:00.000-07:52:58 16986
> Expected:
> 2016-07-04
> Note that all the information to produce the right information is available
> to Drill:
> 1. The DATE annotation says the meaning of the signed 32-bit integer.
> 2. Given the starting point and duration in days, the conversion to Drill's
> own internal date format is unambiguous.
> 3. The DATE annotation says that the date is local, so Drill should not
> attempt to convert to UTC. (That is, a Java Date object can't be used,
> instead a Joda/Java 8 LocalDate is necessary.)
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