sys.gen_random_uuid()

Generate a random UUID value (version 4).

SYS.GEN_RANDOM_UUID()

This function does not have any parameters. The parentheses are required. Include sys. before the function name if the sys schema is not in your search path. For information about the UUID data type, see UUID.

For example:

premdb=# select sys.gen_random_uuid();
           gen_random_uuid            
--------------------------------------
 f280eb64-a88f-40d8-9fc0-f345fc4d2726
(1 row)

Add a UUID column to a table called newmatchstats, then generate unique values for it:

premdb=# alter table newmatchstats add column matchid uuid;
ALTER TABLE
premdb=# \d newmatchstats;
        Table "public.newmatchstats"
  Column  |         Type         | Modifiers 
----------+----------------------+-----------
 seasonid | smallint             | 
 matchday | date                 | 
 htid     | smallint             | 
 atid     | smallint             | 
 moment   | character varying(5) | 
 matchid  | uuid                 | 

Distribution: Hash (seasonid)

premdb=# update newmatchstats set matchid=sys.gen_random_uuid();
UPDATE 524966

premdb=# select count(distinct matchid) from newmatchstats;
 count  
--------
 524966
(1 row)

The COUNT(DISTINCT) query verifies the uniqueness of the generated UUID values.