MySQL 慢查询日志(Slow Query Log) - 数据库编程

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root@localhost[tempdb]> set global log_queries_not_using_indexes=1;
Query OK, 0 rows affected (0.00 sec)

--查看表tb_slow索引信息，表tb_slow无任何索引
root@localhost[tempdb]> show index from tb_slow;
Empty set (0.00 sec)

root@localhost[tempdb]> select count(*) from tb_slow;
+----------+
| count(*) |
+----------+
| 424448 |
+----------+
1 row in set (0.20 sec)

root@localhost[tempdb]> system tail -n3 /var/lib/mysql/suse11b-slow.log
# Query_time: 0.199840 Lock_time: 0.000152 Rows_sent: 1 Rows_examined: 424448
SET timestamp=1412432188;
select count(*) from tb_slow; --此次查询时间为0.199840，被记录的原因是因为没有走索引，因为表本身没有索引

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MySQL 慢查询日志(Slow Query Log)(三)