自动收集统计信息，一直没成功过。--GC life time is shorter

我先调整下tidb_gc_life_time参数，观察观察。

MySQL [(none)]> 
MySQL [(none)]> show variables like  '%tidb_max_auto_analyze_time%' ;
+----------------------------+-------+
| Variable_name              | Value |
+----------------------------+-------+
| tidb_max_auto_analyze_time | 43200 |
+----------------------------+-------+
1 row in set (0.00 sec)

MySQL [(none)]> show variables like  '%tidb_gc_life_time%' ;
+-------------------+-------+
| Variable_name     | Value |
+-------------------+-------+
| tidb_gc_life_time | 10m0s |
+-------------------+-------+
1 row in set (0.00 sec)

MySQL [(none)]> set global tidb_gc_life_time='20m';
Query OK, 0 rows affected (0.04 sec)