hadoop - 时间戳是否与 Apache Hive 中的时区一起存储？

Question

下面的讨论似乎表明 Hive 时间戳有一个时区: https://community.hortonworks.com/questions/83523/timestamp-in-hive-without-timezone.html

apache wiki 说“时间戳被解释为无时区并存储为与 UNIX 纪元的偏移量。”

我指的是:https://cwiki.apache.org/confluence/display/Hive/LanguageManual+Types#LanguageManualTypes-TimestampstimestampTimestamps

如果我使用如下代码:

from_unixtime(unix_timestamp(ts_field,'yyyy-MM-dd HH:mm:ss'), 'yyyy-MM-dd HH:mm:ss z') as ts_field_tz

这似乎暴露了一个潜在的时区值。

Answer 1

短语“无时区”具有误导性；它的实际意思是……

If you have data files written by Hive, those TIMESTAMP values represent the local timezone of the host where the data was written

这是 Impala documentation 的摘录-- 他们说得非常明确，因为当您需要从 Hive 和 Impala 访问同一个表时，这真的很痛苦，因为与 Hive 相反...

By default, Impala does not store timestamps using the local timezone, to avoid undesired results from unexpected time zone issues. Timestamps are stored and interpreted relative to UTC