实例讲解MySQL统计库表大小

SELECT table_schema,table_name,table_rows,data_length+index_length+ data_free data_size
 FROM information_schema.`TABLES` WHERE table_schema IN ('db1','db2')；

mkdir -p /usr/local/data_size

SQL> create database bak_db;

SQL> use bak_db;
SQL>CREATE PROCEDURE `p_db_size`()
BEGIN
DECLARE v_id INT;
DECLARE v_maxid INT;
DECLARE v_tbname VARCHAR(50);
DECLARE v_dbname VARCHAR(50);
DECLARE v_sql_upd VARCHAR(200);
SET v_id =(SELECT MIN(id) FROM bak_db.tb_size);
SET v_maxid =(SELECT MAX(id) FROM bak_db.tb_size);
WHILE v_id <=v_maxid
DO
SET v_tbname = (SELECT tbname FROM bak_db.tb_size WHERE id=v_id);
SET v_dbname = (SELECT dbname FROM bak_db.tb_size WHERE id=v_id);
SET v_sql_upd = CONCAT('update bak_db.tb_size set tb_rows=(select count(*) from ',v_dbname,".",v_tbname,") where id=",v_id);
  SET @v_sql_upd := v_sql_upd;
  PREPARE stmt FROM @v_sql_upd;
  EXECUTE stmt ;
  DEALLOCATE PREPARE stmt;
  SET v_id = v_id +1;
END WHILE;
  END;

vim    data.sh
/* 插入如下内容*/

#! /bin/bash
cd /usr/local/data_size
du -s /data/mysql/mysql3306/data/db1/* |grep -v ".frm" |grep -v ".opt" >/usr/local/data_size/data_size     
du -s /data/mysql/mysql3306/data/db2/* |grep -v ".frm" |grep -v ".opt"/usr/local/data_size/data_size

# 后面4步是拼接成sql 
awk '{print "insert into bak_db.tb_size(size,tb_route)values("""$0}' /usr/local/data_size/data_size >/usr/local/data_size/data_size1  
awk '{print $0";"}' /usr/local/data_size/data_size1 >/usr/local/data_size/data_size.sql
sed -i "s#\t#,'#g" /usr/local/data_size/data_size.sql
sed -i "s#;#');#g" /usr/local/data_size/data_size.sql

# 创建统计表
 /usr/local/mysql5.7/bin/mysql -uroot -p'Test#123456' -h 192.168.28.132 -e "drop table if exists bak_db.tb_size;CREATE TABLE IF NOT EXISTS bak_db.tb_size ( id INT(11) NOT NULL PRIMARY KEY AUTO_INCREMENT ,size INT,tb_route VARCHAR(200),tbname VARCHAR(50),dbname VARCHAR(50),tb_rows INT(11));" 

# 导入数据
 /usr/local/mysql5.7/bin/mysql -uroot -p'Test#123456' -h 192.168.28.132 -e "use bak_db;truncate table bak_db.tb_size;source /usr/local/data_size/data_size.sql;"

# 生成库名及表名，当然该步骤也可以从数据字段中获取
 /usr/local/mysql5.7/bin/mysql -uroot -p'Test#123456' -h 192.168.28.132 -e "use bak_db;UPDATE bak_db.tb_size SET tbname=REPLACE(SUBSTRING_INDEX(tb_route,'/',-1),'.ibd','');"
 /usr/local/mysql5.7/bin/mysql -uroot -p'Test#123456' -h 192.168.28.132 -e "UPDATE bak_db.tb_size SET dbname=LEFT (SUBSTRING_INDEX(tb_route,'/',-2),INSTR(SUBSTRING_INDEX(tb_route,'/',-2),'/')-1);"
sleep 10       # 如果之前的步骤在主库金学习学习，则建议暂停一段时间 以免后面统计的时候无法获得表及内容，如果前面的步骤都在从库，则可以省略该步骤
echo 'start call procedure' 
# 调用存储过程 统计每个表的记录条数
/usr/local/mysql5.7/bin/mysql -uroot -p'Test#123456' -h 192.168.28.132 -e "use bak_db;call bak_db.p_db_size();"

# 把表及数据导出
/usr/local/mysql5.7/bin/mysqldump -uroot -p'Test#123456' -h 192.168.28.132 --single-transaction bak_db tb_size >/usr/local/data_size/tb_size.sql

# 将表及结果导入主库（从库相当于删除在重建了一次）
/usr/local/mysql5.7/bin/mysql -uroot -p'Test#123456' -h 192.168.28.128 -e "use bak_db;source /usr/local/data_size/tb_size.sql;"