This topic describes how to use the TRACE statement.
You can execute the TRACE statement to view the execution result of an SQL statement. You must use the TRACE <SQL> statement and the SHOW TRACE statement together.
Note The difference between the TRACE <SQL> statement and the EXPLAIN <SQL> statement is
that the TRACE <SQL> statement is executed.
Examples
Use the TRACE statement to view the execution result of the select 1 statement.
mysql> trace select 1;
+---+
| 1 |
+---+
| 1 |
+---+
1 row in set (0.03 sec)
mysql> show trace;
+------+----------+----------------+-----------------------------------+---------------+--------------------------+------+-----------+--------+
| ID | TYPE | GROUP_NAME | DBKEY_NAME | TIME_COST(MS) | CONNECTION_TIME_COST(MS) | ROWS | STATEMENT | PARAMS |
+------+----------+----------------+-----------------------------------+---------------+--------------------------+------+-----------+--------+
| 0 | Optimize | DRDS | DRDS | 3 | 0.00 | 0 | select 1 | NULL |
| 1 | Query | TDDL5_00_GROUP | db218249098_sqa_zmf_tddl5_00_3309 | 7 | 0.15 | 1 | select 1 | NULL |
+------+----------+----------------+-----------------------------------+---------------+--------------------------+------+-----------+--------+
2 rows in set (0.01 sec)