這篇文章給大家介紹怎么進(jìn)行MySQL 5.5 MyISAM表鎖測試，內(nèi)容非常詳細(xì)，感興趣的小伙伴們可以參考借鑒，希望對大家能有所幫助。

成都創(chuàng)新互聯(lián)公司專業(yè)為企業(yè)提供加格達(dá)奇網(wǎng)站建設(shè)、加格達(dá)奇做網(wǎng)站、加格達(dá)奇網(wǎng)站設(shè)計(jì)、加格達(dá)奇網(wǎng)站制作等企業(yè)網(wǎng)站建設(shè)、網(wǎng)頁設(shè)計(jì)與制作、加格達(dá)奇企業(yè)網(wǎng)站模板建站服務(wù)，十年加格達(dá)奇做網(wǎng)站經(jīng)驗(yàn)，不只是建網(wǎng)站，更提供有價(jià)值的思路和整體網(wǎng)絡(luò)服務(wù)。

對于MyISAM表，加的鎖是表級鎖；寫操作會阻塞讀操作，讀操作會阻塞寫操作，寫操作會阻塞寫操作；讀操作不會阻塞讀操作。

測試一，會話①的讀操作阻塞會話②的寫操作
會話①
mysql> create table t2(id tinyint(3) unsigned not null auto_increment,
    ->  name varchar(10) not null,
    ->  primary key(id))
    ->  engine=myisam auto_increment=8 default charset=gbk;
Query OK, 0 rows affected (0.03 sec)
mysql> insert into t2(name) values('Neo');
Query OK, 1 row affected (0.03 sec)
mysql> insert into t2(name) values('Trinity');
Query OK, 1 row affected (0.00 sec)

mysql> select * from t2;
+----+---------+
| id | name    |
+----+---------+
|  8 | Neo     |
|  9 | Trinity |
+----+---------+
2 rows in set (0.00 sec)

mysql> desc t2;
+-------+---------------------+------+-----+---------+----------------+
| Field | Type                | Null | Key | Default | Extra          |
+-------+---------------------+------+-----+---------+----------------+
| id    | tinyint(3) unsigned | NO   | PRI | NULL    | auto_increment |
| name  | varchar(10)         | NO   |     | NULL    |                |
+-------+---------------------+------+-----+---------+----------------+
2 rows in set (0.09 sec)

為表增加讀鎖
mysql> lock table t2 read;
Query OK, 0 rows affected (0.00 sec)

會話②
mysql> select * from t2;
+----+---------+
| id | name    |
+----+---------+
|  8 | Neo     |
|  9 | Trinity |
+----+---------+
2 rows in set (0.00 sec)

會話會處于等待狀態(tài)
mysql> update t2 set name='James' where id=5;

會話①
mysql> show processlist;
+----+-----------------+-----------+------+---------+--------+-----------------------------------------------------------------------------+---------------------------------------+
| Id | User            | Host      | db   | Command | Time   | State                                                                       | Info                                  |
+----+-----------------+-----------+------+---------+--------+-----------------------------------------------------------------------------+---------------------------------------+
|  1 | system user     |           | NULL | Connect | 748155 | Slave has read all relay log; waiting for the slave I/O thread to update it | NULL                                  |
|  2 | system user     |           | NULL | Connect | 748156 | Connecting to master                                                        | NULL                                  |
| 13 | event_scheduler | localhost | NULL | Daemon  | 600105 | Waiting on empty queue                                                      | NULL                                  |
| 74 | neo             | localhost | fire | Query   |      0 | NULL                                                                        | show processlist                      |
| 75 | neo             | localhost | fire | Query   |     83 | Waiting for table level lock                                                | update t2 set name='James' where id=5 |
+----+-----------------+-----------+------+---------+--------+-----------------------------------------------------------------------------+---------------------------------------+
5 rows in set (0.00 sec)

mysql> unlock tables;
Query OK, 0 rows affected (0.00 sec)

會話②
mysql> update t2 set name='James' where id=5;
Query OK, 0 rows affected (1 min 48.96 sec)
Rows matched: 0  Changed: 0  Warnings: 0

測試二，會話①的寫操作阻塞會話②的讀操作

會話①
mysql> lock table t2 write;
Query OK, 0 rows affected (0.00 sec)

mysql> insert into t2(name) values('Jack');
Query OK, 1 row affected (0.01 sec)

mysql> commit;
Query OK, 0 rows affected (0.00 sec)

mysql> show processlist;
+----+-----------------+-----------+------+---------+--------+-----------------------------------------------------------------------------+------------------+
| Id | User            | Host      | db   | Command | Time   | State                                                                       | Info             |
+----+-----------------+-----------+------+---------+--------+-----------------------------------------------------------------------------+------------------+
|  1 | system user     |           | NULL | Connect | 748422 | Slave has read all relay log; waiting for the slave I/O thread to update it | NULL             |
|  2 | system user     |           | NULL | Connect | 748423 | Connecting to master                                                        | NULL             |
| 13 | event_scheduler | localhost | NULL | Daemon  | 600372 | Waiting on empty queue                                                      | NULL             |
| 74 | neo             | localhost | fire | Query   |      0 | NULL                                                                        | show processlist |
| 75 | neo             | localhost | fire | Query   |      2 | Waiting for table metadata lock                                             | select * from t2 |
+----+-----------------+-----------+------+---------+--------+-----------------------------------------------------------------------------+------------------+
5 rows in set (0.00 sec)

會話②
查詢會阻塞
mysql> select * from t2;

會話①
mysql> unlock tables;
Query OK, 0 rows affected (0.00 sec)

會話②
mysql> select * from t2;
+----+---------+
| id | name    |
+----+---------+
|  8 | Neo     |
|  9 | Trinity |
| 10 | Jack    |
+----+---------+
3 rows in set (47.89 sec)

當(dāng)同一個(gè)會話中，鎖定一張表后，查詢另外一張表會報(bào)錯(cuò)
mysql> lock table test read;
Query OK, 0 rows affected (0.00 sec)

mysql> select * from test where id=80;
+------+------+
| id   | name |
+------+------+
|   80 | Lily |
+------+------+
1 row in set (0.00 sec)

mysql> select * from t70;
ERROR 1100 (HY000): Table 't70' was not locked with LOCK TABLES

使用表的別名會報(bào)錯(cuò)
mysql> lock table test read;
Query OK, 0 rows affected (0.00 sec)

mysql> select * from test t where id=80;
ERROR 1100 (HY000): Table 't' was not locked with LOCK TABLES

需要對別名進(jìn)行鎖定

mysql> lock table test t read;
Query OK, 0 rows affected (0.00 sec)

mysql> select * from test t where id=80;
+------+------+
| id   | name |
+------+------+
|   80 | Kame |
+------+------+
1 row in set (0.00 sec)

關(guān)于怎么進(jìn)行MySQL 5.5 MyISAM表鎖測試就分享到這里了，希望以上內(nèi)容可以對大家有一定的幫助，可以學(xué)到更多知識。如果覺得文章不錯(cuò)，可以把它分享出去讓更多的人看到。

網(wǎng)頁標(biāo)題：怎么進(jìn)行MySQL5.5MyISAM表鎖測試
本文鏈接：http://aaarwkj.com/article26/pcdecg.html

成都網(wǎng)站建設(shè)公司_創(chuàng)新互聯(lián)，為您提供網(wǎng)站制作、App開發(fā)、品牌網(wǎng)站設(shè)計(jì)、微信公眾號、用戶體驗(yàn)、軟件開發(fā)

廣告

聲明：本網(wǎng)站發(fā)布的內(nèi)容（圖片、視頻和文字）以用戶投稿、用戶轉(zhuǎn)載內(nèi)容為主，如果涉及侵權(quán)請盡快告知，我們將會在第一時(shí)間刪除。文章觀點(diǎn)不代表本網(wǎng)站立場，如需處理請聯(lián)系客服。電話：028-86922220；郵箱：631063699@qq.com。內(nèi)容未經(jīng)允許不得轉(zhuǎn)載，或轉(zhuǎn)載時(shí)需注明來源： 創(chuàng)新互聯(lián)