转自：列式数据库的简单分析

#include <iostream>#include <fstream>#include <cstdlib>#include <memory>#include <string>#include <cstring>#include <time.h>#include <map> #define MAXINT RAND_MAX#define MAXROWS 1000000#define MINVAL 1#define MAXVAL 150000000 using namespace std;  /*计时器*/class Timer {public :    //构造函数    Timer ();    //析构函数    ~Timer ();    //开始计时    void begin();    //计时结束    void end();    //获取时间,ms    double get_time();private :    clock_t start, finish;    double time;}; Timer::Timer () {    start = 0;    finish = 0;} Timer::~Timer () {    start = 0;    finish = 0;} void Timer::begin () {    start = clock();} void Timer::end () {    finish = clock();} double Timer::get_time() {    time = (double)(finish-start)/CLOCKS_PER_SEC*1000;    return time;} //计时器Timer timer; /*记录各种结构表的空间占用*/struct Size {    struct {        struct {            int _static;            int _dynamic;        } col,row;    } mem,file;} size; /*记录各种结构表的文件指针*/struct File {    struct {        struct {            fstream _static;            fstream _dynamic;        } table,index;    } col,row;} file; /*静态行式表结构*/struct StaticRowTable {    int     id;    char    name[255];    int     num;    double  score;    bool    flag;} * static_row_table; /*静态行式表索引*/struct StaticRowTableIndex {    multimap<int,int>    id;    multimap<char*,int>  name;    multimap<int,int>    num;    multimap<double,int> score;    multimap<bool,int>   flag;} static_row_table_index; /*静态列式表结构*/struct StaticColTable {    int*     id;    char     (*name)[255];    int*     num;    double*  score;    bool*    flag;} static_col_table; /*动态行式表结构*/struct DynamicRowTable {    int    id;    int    char_len;    char   *name;    int    num;    double score;    bool   flag;} * dynamic_row_table; /*动态行式表索引*/struct DynamicRowTableIndex {    multimap<int,int>    id;    multimap<char*,int>  name;    multimap<int,int>    num;    multimap<double,int> score;    multimap<bool,int>   flag;} dynamic_row_table_index; /*动态列式表结构*/struct DynamicColTable {    int*    id;    int*    char_len;    char**  name;    int*    num;    double* score;    bool*   flag;} * dynamic_col_table; /*随机字符*/char randChar() {    return rand()%26+‘A‘;} /*随机字符串*/void randString(char col[], int len) {    for(int i=0; i<len; ++i) {        col[i] = randChar();    }} /*初始化表数据*/void init_StaticTable() {    double time;     cout << "+-----静态数据-----+" << endl;     //分配空间    cout << "分配空间中......" << endl;    timer.begin();    static_row_table = new StaticRowTable[MAXROWS];    static_col_table.id = new int[MAXROWS];    static_col_table.name = new char[MAXROWS][255];    static_col_table.num = new int[MAXROWS];    static_col_table.score = new double[MAXROWS];    static_col_table.flag = new bool[MAXROWS];    timer.end();    time = timer.get_time();    cout << "空间分配完毕!" << endl         << "分配空间耗时: "          << time << "ms" << endl;     //产生随机数据和索引    cout << "生成数据中......" << endl;    timer.begin();    for(int i=0; i<MAXROWS; ++i) {        static_col_table.id[i] =         static_row_table[i].id = i;        static_row_table_index.id.insert(pair<int,int>(static_row_table[i].id,i));         randString(static_row_table[i].name, rand()%20+1);        strcpy(static_col_table.name[i],static_row_table[i].name);        static_row_table_index.name.insert(pair<char*,int>(static_col_table.name[i],i));         static_col_table.num[i] =        static_row_table[i].num = rand();        static_row_table_index.num.insert(pair<int,int>(static_row_table[i].num,i));         static_col_table.score[i] =         static_row_table[i].score = rand()/rand();        static_row_table_index.score.insert(pair<double,int>(static_row_table[i].score,i));         static_col_table.flag[i] =         static_row_table[i].flag = rand()%2;        static_row_table_index.flag.insert(pair<bool,int>(static_row_table[i].flag,i));    }    timer.end();    time = timer.get_time();    cout << "数据生成完毕!" << endl;    cout << "生成数据耗时: "          << time << "ms" << endl;      //初始化文件指针    timer.begin();    file.row.table._static.open("row_table_static.dat", ios::binary | ios::out);    file.row.index._static.open("row_index_static.dat", ios::binary | ios::out);    file.col.table._static.open("col_table_static.dat", ios::binary | ios::out);     if( !file.row.table._static ||        !file.row.index._static ||        !file.col.table._static) {        cout << "打开文件失败" << endl;    }     cout << "正在将数据写入文件......" << endl;    for(int i=0; i<MAXROWS; ++i) {        file.row.table._static.write(reinterpret_cast<char *>(&static_row_table[i]),                                    sizeof(StaticRowTable));    }    file.row.table._static.close();    for(int i=0; i<MAXROWS; ++i) {        file.row.index._static.write(reinterpret_cast<char *>(&static_row_table_index),                                    sizeof(StaticRowTableIndex));    }    file.row.index._static.close();     for(int i=0; i<MAXROWS; ++i) {        file.col.table._static.write(reinterpret_cast<char *>(&static_col_table.id[i]),                                    sizeof(int));    }    for(int i=0; i<MAXROWS; ++i) {        file.col.table._static.write(reinterpret_cast<char *>(static_col_table.name[i]),                                    sizeof(char[255]));    }    for(int i=0; i<MAXROWS; ++i) {        file.col.table._static.write(reinterpret_cast<char *>(&static_col_table.num[i]),                                    sizeof(int));    }    for(int i=0; i<MAXROWS; ++i) {        file.col.table._static.write(reinterpret_cast<char *>(&static_col_table.score[i]),                                    sizeof(double));    }    for(int i=0; i<MAXROWS; ++i) {        file.col.table._static.write(reinterpret_cast<char *>(&static_col_table.flag[i]),                                    sizeof(bool));    }    file.col.table._static.close();    timer.end();    time = timer.get_time();    cout << "数据写入完毕!" << endl;    cout << "写入数据耗时: "          << time << "ms" << endl;     //计算总占用空间    size.mem.row._static = sizeof(*static_row_table)*MAXROWS                    +sizeof(static_row_table_index)*MAXROWS;    size.mem.col._static = (sizeof(int)*2+sizeof(double)                    +sizeof(bool)                    +sizeof(char)*255)*MAXROWS;     cout << "静态行式存储耗费空间: "          << size.mem.row._static/1024/1024 << "M" << endl;    cout << "静态列式存储耗费空间: "          << size.mem.col._static/1024/1024 << "M" << endl;} void init_DynamicTable() {    double time;     cout << "+-----动态数据-----+" << endl;} void init() {    double time1, time2;     srand(time(0));     cout << "======生成数据======" << endl;     init_StaticTable();    init_DynamicTable();} /*SELECT nameFROM table WHERE num BETWEEN MINVAL AND MAXVAL;*/  /*测试内存中静态行存储*/int Mem_Static_testRow() {    double time;    int count = 0;    int id;    multimap<int,int>::iterator it,itlow,itup;     cout << "正在测试内存中读取行式静态表......" << endl;    timer.begin();    itlow = static_row_table_index.num.lower_bound (MINVAL);    itup = static_row_table_index.num.upper_bound (MAXVAL);     for (it=itlow; it!=itup; ++it) {        id = (*it).second;        StaticRowTable row = static_row_table[id];        //结果        //cout << row.id;        /*cout << ‘\t‘ << */row.name;        //cout << ‘\t‘ << row.num;        //cout << endl;        //计数        ++count;    }    timer.end();    time = timer.get_time();    cout << "内存中行式静态表读取测试完毕!" << endl;    cout << "读取耗时:" << time << " ms" << endl;     return count;} /*测试磁盘中静态行存储*/int File_Static_testRow() {    double time;    int count = 0;    int id;    char *name;    int num;    int pos;    StaticRowTable row;    multimap<int,int>::iterator it,itlow,itup;     //初始化文件指针    cout << "正在测试磁盘中读取行式静态表......" << endl;    timer.begin();    file.row.table._static.open("row_table_static.dat", ios::binary | ios::in);    //file.row.index._static.open("row_index_static.dat", ios::binary | ios::in);     if(!file.row.table._static) {        cout << "打开文件失败" << endl;    }    //假设索引在内存中    itlow = static_row_table_index.num.lower_bound (MINVAL);    itup = static_row_table_index.num.upper_bound (MAXVAL);     for (it=itlow; it!=itup; ++it) {        id = (*it).second;        pos = sizeof(StaticRowTable)*id;        file.row.table._static.seekg(pos);        file.row.table._static.read(reinterpret_cast<char *>(&row),                                    sizeof(StaticRowTable));        //结果        //cout << row.id;        /*cout << ‘\t‘ << */row.name;        //cout << ‘\t‘ << row.num;        //cout << endl;        //计数        ++count;    }    file.row.table._static.close();    //file.row.index._static.close();    timer.end();    time = timer.get_time();    cout << "磁盘中行式静态表读取测试完毕!" << endl;    cout << "读取耗时:" << time << " ms" << endl;     return count;} /*测试磁盘中静态列存储*/int Mem_Static_testCol() {    double time;    int count = 0;    int id;    int num;    char *name;     cout << "正在测试内存中列式静态表读取......" << endl;    timer.begin();    for(int i=0; i<MAXROWS; ++i) {        int num = static_col_table.num[i];        if(num>MINVAL and num<MAXVAL) {            //结果            //cout << i;            /*cout << ‘\t‘ << */static_col_table.name[i];            //cout << ‘\t‘ << static_col_table.num[i];            //cout << endl;            //计数            ++count;        }    }    timer.end();    time = timer.get_time();    cout << "内存中列式静态存储表读取测试完毕!" << endl;    cout << "读取耗时:" << time << " ms" << endl;     return count;} /*测试磁盘中静态列存储*/int File_Static_testCol() {    double time;    int count = 0;    int id;    int num;    char *name = new char[255];    int pos_num;    int pos_name;    int pos;     cout << "正在测试磁盘中列式静态表读取......" << endl;    timer.begin();    file.col.table._static.open("col_table_static.dat", ios::binary | ios::in);    fstream tmpfile("col_table_static.dat", ios::binary | ios::in);     if(!file.col.table._static || !tmpfile) {        cout << "打开文件失败" << endl;    }     pos_name = sizeof(int)*MAXROWS;    pos_num = (sizeof(int)            +sizeof(char[255]))*MAXROWS;    file.col.table._static.seekg(pos_num);    for(int i=0; i<MAXROWS; ++i) {        file.col.table._static.read(reinterpret_cast<char *>(&num),                                    sizeof(int));        if(num>MINVAL and num<MAXVAL) {            //结果            id = i;            //cout << id;            pos = pos_name+sizeof(char[255])*id;            tmpfile.seekg(pos);            tmpfile.read(reinterpret_cast<char *>(name),                        sizeof(char[255]));            /*cout << ‘\t‘ << */name;            //cout << ‘\t‘ << num;            //cout << endl;            //计数            ++count;        }    }    file.col.table._static.close();    timer.end();    time = timer.get_time();    cout << "磁盘中列式静态存储表读取测试完毕!" << endl;    cout << "读取耗时:" << time << " ms" << endl;     return count;} void test() {    int count1, count2, count3, count4;     cout << "=====内存存取测试=====" << endl;    cout << "+----静态表测试中----+" << endl;    cout << "*行式存储*" << endl;    //内存中静态行式存储表    count1 = Mem_Static_testRow();    //内存中静态列式存储表    count2 = Mem_Static_testCol();    cout << "*列式存储*" << endl;    //磁盘中静态行式存储表    count3 = File_Static_testRow();    //磁盘中静态行式存储表    count4 = File_Static_testCol();     if (count1==count2 and count2==count3 and count3==count4) {        cout << "共匹配:" << count1 << " 行" << endl;    } else {        cout << "错误:每次匹配行数不同" << endl;    } } int main() {    init();    test();    cout << "All OK!" << endl;    return 0;}