Returns the current connection ID.

mysql> select CONNECTION_ID();
+-----------------+
| CONNECTION_ID() |
+-----------------+
| 6               |
+-----------------+
1 row in set (0.00 sec)

Returns KNN vector search distance.

mysql> select id, knn_dist() from test where knn ( image_vector, 5, (0.286569,-0.031816,0.066684,0.032926) ) and match('white') and id < 10;
+------+------------+
| id   | knn_dist() |
+------+------------+
|    2 | 0.81527930 |
+------+------------+
1 row in set (0.00 sec)

Returns the IDs of documents that were inserted or replaced by the last statement in the current session.

The same value can also be obtained via the @@session.last_insert_id variable.

mysql> select @@session.last_insert_id;
+--------------------------+
| @@session.last_insert_id |
+--------------------------+
| 11,32                    |
+--------------------------+
1 rows in set

mysql> select LAST_INSERT_ID();
+------------------+
| LAST_INSERT_ID() |
+------------------+
| 25,26,29         |
+------------------+
1 rows in set   

Returns a "short" universal identifier as a 63-bit unsigned integer following the same algorithm as for auto-id generation.

NOTE: Using uuid_short() will increase the counter used for auto-IDs, so use it carefully. While you can run uuid_short() in queries like SELECT uuid_short() FROM ..., this approach isn't ideal as it may create large gaps in your auto-generated IDs.

mysql> select uuid_short();
+---------------------+
| uuid_short()        |
+---------------------+
| 5839598169280741377 |
+---------------------+
1 row in set (0.00 sec)

mysql> select uuid_short();
+---------------------+
| uuid_short()        |
+---------------------+
| 5839598169280741378 |
+---------------------+
1 row in set (0.00 sec)