[
https://issues.apache.org/jira/browse/HIVE-4525?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13656226#comment-13656226
]
Eric Hanson commented on HIVE-4525:
-----------------------------------
For vectorized query execution (HIVE-4160), we are going to represent a
timestamp value internally as a vector of 64 bit integers representing the
number of nanos since the epoch (in 1970). Given your proposal to also support
time values before 1970, I'd propose that for vectorized QE we extend this so a
negative number of nanos is used to represent a value before 1970. This gives a
range of 292 years before or after 1970, good enough for practical purposes.
Data outside that range might first not be supported for vectorized QE, and
then later might be supported but revert to a slower code path.
We may want to consider that the storage layer (say ORC) store timestamps
simply as a long, so it is not as expensive to flow this data into vectorized
query execution. With compression, these long values will compress pretty well,
so the storage layout becomes less of a concern and query execution speed
becomes the more pressing issue.
> Support timestamps earlier than 1970 and later than 2038
> --------------------------------------------------------
>
> Key: HIVE-4525
> URL: https://issues.apache.org/jira/browse/HIVE-4525
> Project: Hive
> Issue Type: Bug
> Reporter: Mikhail Bautin
> Assignee: Mikhail Bautin
> Attachments: D10755.1.patch
>
>
> TimestampWritable currently serializes timestamps using the lower 31 bits of
> an int. This does not allow to store timestamps earlier than 1970 or later
> than a certain point in 2038.
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira
