mysql 造1亿条记录的单表--大数据表

读写文件

背景及木：现有数据1000w单表，为压力测试准备1亿条数据。

步骤：

1.将1000w条记录，除id外都导入到多个文件中：

//DELIMITER
DROP PROCEDURE if EXISTS createManyTable;
create PROCEDURE createManyTable()
BEGIN
DECLARE i int;
DECLARE fileName VARCHAR(30);
set i=1;


while i<251
DO
SET fileName=CONCAT('f_log_',i,'.txt');

SET @STMT :=CONCAT("select `xx`,`xx`,`xx`,`xx`,.... into outfile 'temp/",fileName,
"' lines terminated by '
' from `f_log` WHERE id>= ",40000*(i-1)," AND id< ",40000*i);

PREPARE STMT FROM @STMT;
EXECUTE STMT;


set i=i+1;
end while;
END;
//DELIMITER
CALL createManyTable();

2. 将上述多个文件合并到同一个文件，并且在第一列加入id列：

    public static void main(String[] args) throws IOException {
        int i=10000000;
        int step=40000;
        File out=new File("E:/data/f_log_data.txt");
        for(int k=1;k<251;k++){
            File file=new File("E:/data/temp/f_log_"+k+".txt");
            StringBuffer sb=new StringBuffer();
            if(file.exists()){
                sb=readFile(file,i+step*k);
                writeFile(out,sb);
            }
        }
        
    }
    
    public static StringBuffer readFile(File file,int start) throws IOException{
        StringBuffer sb=new StringBuffer();
        BufferedReader reader=new BufferedReader(new FileReader(file));
        String line="";    
        

        while(line != null){
            line = reader.readLine();
            if(line == null){
                break;
            }
            if(line.trim().equalsIgnoreCase("")){
                continue;
            }
            start++;
            sb.append(start+"	"+line.trim()+"
");
        }
        reader.close();
        return sb;
    }
    
    public static void writeFile(File file,StringBuffer sb) throws IOException{
        BufferedWriter writer = new BufferedWriter(new FileWriter(file, true));
        writer.write(sb.toString());
        writer.close();
    }
    
    
    
    public void writeFile11() throws IOException{

        // TODO Auto-generated method stub
        BufferedWriter writer = new BufferedWriter(new FileWriter(new File("D:/driver/data.txt"), true));
        for(int i=0;i<1000000;i++){
            if(i%10==0){
                writer.write("赵"+(i/10)+"	"+ (int)(Math.random()*100)+"
");
            }if(i%10==1){
                writer.write("钱"+(i/10)+"	"+ (int)(Math.random()*100)+"
");
            }
            if(i%10==2){
                writer.write("孙"+(i/10)+"	"+ (int)(Math.random()*100)+"
");
            }if(i%10==3){
                writer.write("李"+(i/10)+"	"+ (int)(Math.random()*100)+"
");
            }
            if(i%10==4){
                writer.write("郑"+(i/10)+"	"+ (int)(Math.random()*100)+"
");
            }if(i%10==5){
                writer.write("吴"+(i/10)+"	"+ (int)(Math.random()*100)+"
");
            }
            if(i%10==6){
                writer.write("周"+(i/10)+"	"+ (int)(Math.random()*100)+"
");
            }if(i%10==7){
                writer.write("王"+(i/10)+"	"+ (int)(Math.random()*100)+"
");
            }
            if(i%10==8){
                writer.write("张"+(i/10)+"	"+ (int)(Math.random()*100)+"
");
            }if(i%10==9){
                writer.write("刘"+(i/10)+"	"+ (int)(Math.random()*100)+"
");
            }
        }
        writer.close();
    
    }

3. 将合并后的文件导入到数据表中：

load data local infile '/tmp/finance_log_data.txt' into table f_log(`id`,`xx`,

`xx`,.........................

);

注意事项：开始考虑使用存储过程来逐步导入到数据表中，但load data命令不能在存储过程中使用。

　　另外，数据的合并也可以以shell脚本完成，但习惯使用java了，因此以java来完成，显得比较复杂。不过，可以随便复习一下java的读写文件，有算不错的经历。

Q&A

时间问题：生成1亿条数据(在有索引的情况下)，用时3个小时。如果使用insert语句，估计会疯掉！