UUID_SHORT

Syntax

UUID_SHORT()

Purpose

Returns a "short" universal identifier in the form of a 64-bit unsigned integer.

The return value of UUID_SHORT() is guaranteed to be unique if the following conditions are met:

• The server_id value of the current server is between 0 and 255 and is unique among a group of source servers and replica servers. If the total number of server_id values exceeds 256, the generated "short" universal identifier cannot be guaranteed to be space-unique, although this function will not return an error.

• Do not set the system time of the server host during OBServer restart.

• The average number of calls to UUID_SHORT() per second during OBServer restart is less than 16 million.

The return value of UUID_SHORT() is constructed as follows:

(server_id & 255) << 56
+ (server_startup_time_in_seconds << 24)
+ incremented_variable++;

Examples

obclient> SELECT UUID_SHORT();
+-----------------------+
|          UUID_SHORT() |
+-----------------------+
| 92395783831158784 |
+-----------------------+
1 row in set