MySQL 使用自增ID主键和UUID 作为主键的优劣比较详细过程（从百万到千万表记录测试）

mysql> select count(1) from UC_USER;

+----------+

| count(1) |

+----------+

|  5720112 |

+----------+

1 row in set (0.00 sec)

mysql>

# uuid为主键的表

mysql> select count(1) from UC_USER_PK_VARCHAR_1;

+----------+

| count(1) |

+----------+

|  5720112 |

+----------+

1 row in set (1.91 sec)

Mysqldump备份

MySQL恢复

mysql> use test;

Database changed

mysql> select count(1) from UC_USER_1;

+----------+

| count(1) |

+----------+

| 10698102 |

+----------+

1 row in set (27.42 sec)

# uuid为主键的表

mysql> select count(1) from UC_USER_PK_VARCHAR_1;

+----------+

| count(1) |

+----------+

| 10698102 |

+----------+

1 row in set (0.00 sec)

mysql>

修改一天的记录

Mysqldump备份

MySQL恢复

import org.slf4j.Logger;

import org.slf4j.LoggerFactory;

public class IdWorker {

protected static final Logger LOG = LoggerFactory.getLogger(IdWorker.class);

private long workerId;

private long datacenterId;

private long sequence = 0L;

private long twepoch = 1288834974657L;

private long workerIdBits = 5L;

private long datacenterIdBits = 5L;

private long maxWorkerId = -1L ^ (-1L << workerIdBits);

private long maxDatacenterId = -1L ^ (-1L << datacenterIdBits);

private long sequenceBits = 12L;

private long workerIdShift = sequenceBits;

private long datacenterIdShift = sequenceBits + workerIdBits;

private long timestampLeftShift = sequenceBits + workerIdBits + datacenterIdBits;

private long sequenceMask = -1L ^ (-1L << sequenceBits);

private long lastTimestamp = -1L;

public IdWorker(long workerId, long datacenterId) {

// sanity check for workerId

if (workerId > maxWorkerId || workerId < 0) {

throw new IllegalArgumentException(String.format("worker Id can‘t be greater than %d or less than 0", maxWorkerId));

}

if (datacenterId > maxDatacenterId || datacenterId < 0) {

throw new IllegalArgumentException(String.format("datacenter Id can‘t be greater than %d or less than 0", maxDatacenterId));

}

this.workerId = workerId;

this.datacenterId = datacenterId;

LOG.info(String.format("worker starting. timestamp left shift %d, datacenter id bits %d, worker id bits %d, sequence bits %d, workerid %d", timestampLeftShift, datacenterIdBits, workerIdBits, sequenceBits, workerId));

}

public synchronized long nextId() {

long timestamp = timeGen();

if (timestamp < lastTimestamp) {

LOG.error(String.format("clock is moving backwards.  Rejecting requests until %d.", lastTimestamp));

throw new RuntimeException(String.format("Clock moved backwards.  Refusing to generate id for %d milliseconds", lastTimestamp - timestamp));

}

if (lastTimestamp == timestamp) {

sequence = (sequence + 1) & sequenceMask;

if (sequence == 0) {

timestamp = tilNextMillis(lastTimestamp);

}

} else {

sequence = 0L;

}

lastTimestamp = timestamp;

return ((timestamp - twepoch) << timestampLeftShift) | (datacenterId << datacenterIdShift) | (workerId << workerIdShift) | sequence;

}

protected long tilNextMillis(long lastTimestamp) {

long timestamp = timeGen();

while (timestamp <= lastTimestamp) {

timestamp = timeGen();

}

return timestamp;

}

protected long timeGen() {

return System.currentTimeMillis();

}

}

import java.util.HashSet;

import java.util.Set;

public class IdWorkerTest {

static class IdWorkThread implements Runnable {

private Set<Long> set;

private IdWorker idWorker;

public IdWorkThread(Set<Long> set, IdWorker idWorker) {

this.set = set;

this.idWorker = idWorker;

}

public void run() {

while (true) {

long id = idWorker.nextId();

System.out.println("            real id:" + id);

if (!set.add(id)) {

System.out.println("duplicate:" + id);

}

}

}

}

public static void main(String[] args) {

Set<Long> set = new HashSet<Long>();

final IdWorker idWorker1 = new IdWorker(0, 0);

final IdWorker idWorker2 = new IdWorker(1, 0);

Thread t1 = new Thread(new IdWorkThread(set, idWorker1));

Thread t2 = new Thread(new IdWorkThread(set, idWorker2));

t1.setDaemon(true);

t2.setDaemon(true);

t1.start();

t2.start();

try {

Thread.sleep(30000);

} catch (InterruptedException e) {

e.printStackTrace();

}

}

}