flink-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "sunjincheng (JIRA)" <j...@apache.org>
Subject [jira] [Created] (FLINK-7205) Add UUID supported in TableAPI/SQL
Date Sun, 16 Jul 2017 23:48:00 GMT
sunjincheng created FLINK-7205:

             Summary: Add UUID supported in TableAPI/SQL
                 Key: FLINK-7205
                 URL: https://issues.apache.org/jira/browse/FLINK-7205
             Project: Flink
          Issue Type: Sub-task
    Affects Versions: 1.4.0
            Reporter: sunjincheng

UUID() returns a value that conforms to UUID version 1 as described in RFC 4122. The value
is a 128-bit number represented as a utf8 string of five hexadecimal numbers in aaaaaaaa-bbbb-cccc-dddd-eeeeeeeeeeee

The first three numbers are generated from the low, middle, and high parts of a timestamp.
The high part also includes the UUID version number.

The fourth number preserves temporal uniqueness in case the timestamp value loses monotonicity
(for example, due to daylight saving time).

The fifth number is an IEEE 802 node number that provides spatial uniqueness. A random number
is substituted if the latter is not available (for example, because the host device has no
Ethernet card, or it is unknown how to find the hardware address of an interface on the host
operating system). In this case, spatial uniqueness cannot be guaranteed. Nevertheless, a
collision should have very low probability.
See: [RFC 4122: http://www.ietf.org/rfc/rfc4122.txt|http://www.ietf.org/rfc/rfc4122.txt]
See detailed semantics:
   MySql: [https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_uuid|https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_uuid]

Welcome anybody feedback -:).

This message was sent by Atlassian JIRA

View raw message