UUID_SHORT()
Returns a "short" universal identifier as a 64-bit unsigned integer (rather than a string-form 128-bit identifier as returned by the UUID() function).
The value of UUID_SHORT()
is guaranteed to be unique if the following conditions hold:
server_id
is between 0 and 255 UUID_SHORT()
on average more than 16 million times per second between mysqld restarts The UUID_SHORT() return value is constructed this way:
(server_id & 255) << 56 + (server_startup_time_in_seconds << 24) + incremented_variable++;
Statements using the UUID_SHORT() function are not safe for statement-based replication.
SELECT UUID_SHORT(); +-------------------+ | UUID_SHORT() | +-------------------+ | 21517162376069120 | +-------------------+
create table t1 (a bigint unsigned default(uuid_short()) primary key); insert into t1 values(),(); select * from t1; +-------------------+ | a | +-------------------+ | 98113699159474176 | | 98113699159474177 | +-------------------+
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Licensed under the Creative Commons Attribution 3.0 Unported License and the GNU Free Documentation License.
https://mariadb.com/kb/en/uuid_short/