Oracle 快速load数据的方法--SQL*Loader

Oracle 快速load数据的方法--SQL*Loader

Oracle可以快速load数据，相比之前测试过的批量插入方法（1KW条记录耗时近2分钟）也要快很多

准备数据文件

在内存的vector中生成1KW条记录，然后写到指定的数据文件中

#include <string.h>
#include <stdio.h>

#include <unistd.h>
#include <vector>
using namespace std;

#include "clocktool.h"

typedef struct User_Record
{
    char id[16];
    char name[32];
    char passwd[16];
}USER_RECORD;

int main(int argc, char** argv)
{
    int iTimes = 10000000;

    vector<User_Record*> vec;
    TimeTool cktool;

    User_Record* pRecord = NULL;
    cktool.begin();
    for (int i = 0; i < iTimes; ++i)
    {
        pRecord = new User_Record;
        memset(pRecord, 0, sizeof(struct User_Record));
        sprintf(pRecord->id, "%d", i);
        sprintf(pRecord->name, "%ld", 18600000000+i);
        strcpy(pRecord->passwd, "111111");
        vec.push_back(pRecord);
    }
    cktool.end();
    printf("cost %f\n", cktool.getInterval());

    cktool.reset();

    cktool.begin();
    FILE* pf = fopen("./load.data", "w");
    if (pf)
    {
        char buff[256];
        int iResult = 0;
        for (int i = 0; i < iTimes; ++i)
        {
            memset(buff, 0, sizeof(buff));
            iResult = sprintf(buff, "%s, %s, %s\n", vec[i]->id, vec[i]->name, vec[i]->passwd);
            fwrite(buff, 1, iResult, pf);
        }
        fclose(pf);
    }
    cktool.end();
    printf("cost %f\n", cktool.getInterval());

    vector<User_Record*>::iterator it = vec.begin();
    for (; it != vec.end(); ++it)
    {
        delete (*it);
    }
    return 0;
}

执行结果：

cost 2.796853
cost 3.715381

通过SQL*Loader加载数据

编写load.ctl文件

load data
infile 'load.data'
into table base_users
fields terminated by ","
(userid, username, passwd)

清除原有数据

SQL> truncate table base_users;

对于大数据量的加载，追求效率的时候建议关闭log

SQL> alter table base_users nologging;

运行load加载命令

sqlldr userid=cat/cat control=load.ctl log=load.log direct=y

通过测试发现其中direct=y非常重要，大幅提升了数据加载的效率。检查load.log日志可以发现执行时间大概就是在12秒左右

Total logical records skipped:          0
Total logical records read:      10000000
Total logical records rejected:         0
Total logical records discarded:        0
Total stream buffers loaded by SQL*Loader main thread:     2204
Total stream buffers loaded by SQL*Loader load thread:        0

Run began on Sat Mar 31 22:47:07 2012
Run ended on Sat Mar 31 22:47:19 2012

Elapsed time was:     00:00:11.73
CPU time was:         00:00:05.31

更多Oracle相关信息见Oracle 专题页面 http://www.bkjia.com/topicnews.aspx?tid=12