mysql 百万条数据分页优化

/*********************************************
类名： PageSupport
功能：分页显示MySQL中的数据
***********************************************/
class PageSupport{
//属性
var $sql; //所要显示数据的SQL查询语句
var $page_size; //每页显示最多行数

var $start_index; //所要显示记录的首行序号
var $total_records; //记录总数
var $current_records; //本页读取的记录数
var $result; //读出的结果

var $total_pages; //总页数 
var $current_page; //当前页数
var $display_count = 30; //显示的前几页和后几页数

var $arr_page_query; //数组，包含分页显示需要传递的参数

var $first;
var $prev;
var $next;
var $last;

//方法
/*********************************************
构造函数：__construct()
输入参数：
$ppage_size：每页显示最多行数
***********************************************/
function PageSupport($ppage_size)
{
$this->page_size=$ppage_size;
$this->start_index=0;
}

/*********************************************
构造函数：__destruct()
输入参数：
***********************************************/
function __destruct()
{

}

/*********************************************
get函数：__get()
***********************************************/
function __get($property_name)
{ 
if(isset($this->$property_name))
{
return($this->$property_name);
}
else
{
return(NULL);
}
}

/*********************************************
set函数：__set()
***********************************************/
function __set($property_name, $value)
{
$this->$property_name = $value;
}

/*********************************************
函数名：read_data
功能： 根据SQL查询语句从表中读取相应的记录
返回值：属性二维数组result[记录号][字段名]
***********************************************/
function read_data()
{
$ql=$this->sql;

//查询数据，数据库链接等信息应在类调用的外部实现
$result=_query($psql) or die(mysql_error());
$this->total_records=mysql_num_rows($result);

//利用LIMIT关键字获取本页所要显示的记录
if($this->total_records>0)
{
$this->start_index = ($this->current_page-1)*$this->page_size;
$psql=$psql. " LIMIT ".$this->start_index." , ".$this->page_size;

$result=mysql_query($psql) or die(mysql_error());
$this->current_records=mysql_num_rows($result);

//将查询结果放在result数组中
$i=0;
while($row=mysql_fetch_Array($result))
{
$this->result[$i]=$row;
$i++;
}
}

//获取总页数、当前页信息
$this->total_pages=ceil($this->total_records/$this->page_size); 

$this->first=1;
$this->prev=$this->current_page-1;
$this->next=$this->current_page+1;
$this->last=$this->total_pages;
}

/*********************************************
函数名：standard_navigate()
功能： 显示首页、下页、上页、未页
***********************************************/
function standard_navigate()
{
echo "

}

/*********************************************
函数名：full_navigate()
功能： 显示首页、下页、上页、未页 
生成导航链接 如1 2 3 ... 10 11
***********************************************/
function full_navigate()
{
echo "

}

}
?>

调用:

include_once("../config_jj/sys_conf.inc");
include_once("../PageSupportClass.php");//分页类
include_once('../Smarty_JsnhClass.php');

$smarty = new Smarty_Jsnh();
include_once("../include/Smarty_changed_dir.php");
$smarty->assign('title', "Smarty新闻分页测试");

$pageSupport = new PageSupport($PAGE_SIZE); //实例化PageSupport对象

$current_page=$_GET["current_page"];//分页当前页数

if (isset($current_page)) {

$pageSupport->__set("current_page",$current_page);

} else {

$pageSupport->__set("current_page",1);

}

?>
$pageSupport->__set("sql"," * from news ");
$pageSupport->read_data();//读数据

if ($pageSupport->current_records > 0) //如果数据不为空，则组装数据
{
for ($i=0; $icurrent_records; $i++)
{
$title = $pageSupport->result[$i]["title"];
$id = $pageSupport->result[$i]["id"];

$news_arr[$i] = array('news' => array('id' => $id,'title' => $title));

}
}

//关闭数据库
mysql_close($db);

$pageinfo_arr = array(
'total_records' => $pageSupport->total_records,
'current_page' => $pageSupport->current_page,
'total_pages' => $pageSupport->total_pages,
'first' => $pageSupport->first,
'prev' => $pageSupport->prev,
'next' => $pageSupport->next,
'last' => $pageSupport->last
);

$smarty->assign('results', $news_arr);
$smarty->assign('pageSupport', $pageinfo_arr);
$smarty->display('news/list.tpl');

?>
模板list.tpl
{* I am a Smarty comment, I don't exist in the compiled output *}
{*
{$pageSupport.total_records}

{$pageSupport.current_page}

{$pageSupport.total_pages}

{$pageSupport.first}

{$pageSupport.prev}

{$pageSupport.next}

{$pageSupport.last}

*}

{foreach item=o from=$results}
{$o.news.id} {$o.news.title}

 
{foreachelse}
娌℃湁鎮ㄨ