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Greg Rahn commented on ARROW-637: --------------------------------- [~julianhyde] - Oracle has 3 timestamp types (from https://docs.oracle.com/database/121/SQLRF/sql_elements001.htm#SQLRF0021) * timestamp w/o time zone * timestamp with local time zone ** Data is normalized to the database time zone when it is stored in the database. ** When the data is retrieved, users see the data in the session time zone. * timestamp with time zone ** Data is stored with an explicit time zone, but not adjusted/normalized for local time zone. ** Value returned contains time zone offset information. The ANSI and Oracle w/o TZ versions are the same, but the ANSI with TZ aligns more to Oracle's with LOCAL TZ. {noformat} create table ts ( ts_string varchar(50), ts_timestamp timestamp, ts_timestamp_tz timestamp with time zone, ts_timestamp_ltz timestamp with local time zone ); insert into ts values ( '2016-01-01 00:00:00 +10:00', timestamp '2016-01-01 00:00:00 +10:00', timestamp '2016-01-01 00:00:00 +10:00', timestamp '2016-01-01 00:00:00 +10:00' ); alter session set NLS_TIMESTAMP_FORMAT = 'YYYY-MM-DD HH24:MI:SSXFF'; alter session set NLS_TIMESTAMP_TZ_FORMAT = 'YYYY-MM-DD HH24:MI:SSXFF TZR'; select dbtimezone from dual; DBTIME ------ +00:00 select sessiontimezone from dual; SESSIONTIMEZONE --------------- -05:00 select * from ts; TS_STRING TS_TIMESTAMP TS_TIMESTAMP_TZ TS_TIMESTAMP_LTZ -------------------------- -------------------------- --------------------------------- -------------------------- 2016-01-01 00:00:00 +10:00 2016-01-01 00:00:00.000000 2016-01-01 00:00:00.000000 +10:00 2015-12-31 09:00:00.000000 {noformat} > [Format] Add time zone metadata to Timestamp type > ------------------------------------------------- > > Key: ARROW-637 > URL: https://issues.apache.org/jira/browse/ARROW-637 > Project: Apache Arrow > Issue Type: New Feature > Components: Format > Reporter: Wes McKinney > Assignee: Wes McKinney > > As a metadata-only convenience, it would be useful to have an optional Olson > time zone name or absolute time offset (e.g. {{+07:30}}) in the {{Timestamp}} > flatbuffers type: > https://github.com/apache/arrow/blob/master/format/Message.fbs#L94 > Null or length-0 string would indicate that the data is time zone naive, and > shall not be considered to be localized. > https://github.com/apache/arrow/pull/388 -- This message was sent by Atlassian JIRA (v6.3.15#6346)