orc Minimum is error?

[hongli-my]

write orc file:

output = open("/tmp/new.orc", "wb")
writer = pyorc.Writer(output, "struct<col0:int,col1:string,col2:timestamp>", timezone=zoneinfo.ZoneInfo('Asia/Shanghai'))
t = datetime(2022, 4, 10, 9, 30, 30, 0)
writer.write((100, "1000", t))
writer.close()

use orc-statistics to show

--- Column 3 ---
Data type: Timestamp
Values: 1
Has null: no
Minimum: 2022-04-10 03:30:58.800
LowerBound: 2022-04-10 03:30:58.800
Maximum: 2022-04-10 03:30:58.800
UpperBound: 2022-04-10 03:30:58.801

./orc-1.7.3/build/tools/src/orc-contents /tmp/new.orc
{"col0": 100, "col1": "1000", "col2": "2022-04-10 11:30:30.0"}

why Maximum or Minimum is 2022-04-10 03:30:58.800

[hongli-my]

use java example https://www.jianshu.com/p/a9f8b7aa3c28 is right

[noirello]

Thank you for reporting.
It seems like any issue in the C++ core lib with timestamp columns, when the writer's time zone is not UTC.

I opened a PR to fix it.

[noirello]

0.7.0 has been released, using ORC C++ Core 1.7.5 with the time zone fix.