demo@127.0.0.1:26257/defaultdb> create table t (u uuid);
CREATE TABLE


Time: 5ms total (execution 5ms / network 0ms)

demo@127.0.0.1:26257/defaultdb> insert into t values ('eb64afe6-ade7-40ce-8352-4bb5eec39075');
INSERT 0 1


Time: 5ms total (execution 5ms / network 0ms)

demo@127.0.0.1:26257/defaultdb> select u || 'a' from t;
                     ?column?
--------------------------------------------------
  \xebd\xaf\xe6\xad\xe7@\u0383RK\xb5\xee\u00d0ua
(1 row)


Time: 1ms total (execution 1ms / network 0ms)

demo@127.0.0.1:26257/defaultdb> set vectorize = off;
SET


Time: 0ms total (execution 0ms / network 0ms)

demo@127.0.0.1:26257/defaultdb> select u || 'a' from t;
                ?column?
-----------------------------------------
  eb64afe6-ade7-40ce-8352-4bb5eec39075a
(1 row)