sys_guid() function

1. Purpose

IvorySQL’s sys_guid() is a powerful random number generation function that generates and returns a 16-byte database-level unique identifier (raw value).

2. Implementation Description

The sys_guid() function of IvorySQL is implemented by modifying the code of the uuid-ossp plugin. To make full use of various underlying libraries of uuid, the following logic is adopted:

  1. If the uuid-ossp exists in the system, uuid_make() will be used;

  2. If the uuid-e2fs exists in the system, uuid_generate_random() will be used；

  3. Otherwise use arc4random()；

Meanwhile modify the code so that IvorySQL can load uuid-ossp extension automatically.