PHP提取数据很慢

如何解决PHP提取数据很慢

我有一个包含许多sql语句（postgres-db）的PHP文件，执行查询大约需要1秒钟。但是我认为获取数据需要很长时间。有没有一种方法可以使这部分更快：

<?PHP

// Call this at each point of interest,passing a descriptive string
function prof_flag($str)
{
    global $prof_timing,$prof_names;
    $prof_timing[] = microtime(true);
    $prof_names[] = $str;
}

// Call this when you're done and want to see the results
function prof_print()
{
    global $prof_timing,$prof_names;
    $size = count($prof_timing);
    for($i=0;$i<$size - 1; $i++)
    {
        echo "<b>{$prof_names[$i]}</b><br>";
        echo sprintf("&nbsp;&nbsp;&nbsp;%f<br>",$prof_timing[$i+1]-$prof_timing[$i]);
    }
    echo "<b>{$prof_names[$size-1]}</b><br>";
}

prof_flag("Start");
$time_start = microtime(true);


prof_flag("Connect to DB");

require("PHP/00connection.PHP");


prof_flag("Perform query");

$stmt_dbstorage_helium = $conn->query("SELECT used_space,epoch_time FROM db_storage WHERE host_id = 1 ORDER BY epoch_time;")->fetchAll();
$stmt_dbstorage_neon = $conn->query("SELECT used_space,epoch_time FROM db_storage WHERE host_id = 2 ORDER BY epoch_time;")->fetchAll();
$stmt_dbstorage_argon = $conn->query("SELECT used_space,epoch_time FROM db_storage WHERE host_id = 3 ORDER BY epoch_time;")->fetchAll();
$stmt_dbstorage_krypton = $conn->query("SELECT used_space,epoch_time FROM db_storage WHERE host_id = 4 ORDER BY epoch_time;")->fetchAll();

$stmt_available_tickets_helium =  $conn->query("SELECT read_tickets,write_tickets,epoch_time FROM tickets_available WHERE host_id=1 ORDER BY epoch_time;")->fetchAll();
$stmt_available_tickets_neon =  $conn->query("SELECT read_tickets,epoch_time FROM tickets_available WHERE host_id=2 ORDER BY epoch_time;")->fetchAll();
$stmt_available_tickets_argon =  $conn->query("SELECT read_tickets,epoch_time FROM tickets_available WHERE host_id=3 ORDER BY epoch_time;")->fetchAll();
$stmt_available_tickets_krypton =  $conn->query("SELECT read_tickets,epoch_time FROM tickets_available WHERE host_id=4 ORDER BY epoch_time;")->fetchAll();

$stmt_connections_helium = $conn->query("SELECT connections,epoch_time FROM connections WHERE host_id = 1 ORDER BY epoch_time;")->fetchAll();
$stmt_connections_neon = $conn->query("SELECT connections,epoch_time FROM connections WHERE host_id = 2 ORDER BY epoch_time;")->fetchAll();
$stmt_connections_argon = $conn->query("SELECT connections,epoch_time FROM connections WHERE host_id = 3 ORDER BY epoch_time;")->fetchAll();
$stmt_connections_krypton = $conn->query("SELECT connections,epoch_time FROM connections WHERE host_id = 4 ORDER BY epoch_time;")->fetchAll();


prof_flag("Retrieve data");


foreach ($stmt_dbstorage_argon as $row) { $used_space_argon[] = "[".$row['epoch_time'].",".$row['used_space']."]";  }
foreach ($stmt_dbstorage_helium as $row) {  $used_space_helium[] = "[".$row['epoch_time'].",".$row['used_space']."]";  }
foreach ($stmt_dbstorage_neon as $row) { $used_space_neon[] = "[".$row['epoch_time'].",".$row['used_space']."]"; }  
foreach ($stmt_dbstorage_krypton as $row) { $used_space_krypton[] = "[".$row['epoch_time'].",".$row['used_space']."]";    } 

foreach ($stmt_available_tickets_helium as $row) {
    $read_tickets_helium[] = "[".$row['epoch_time'].",".$row['read_tickets']."]";
    $write_tickets_helium[] = "[".$row['epoch_time'].",".$row['write_tickets']."]";
 }

foreach ($stmt_available_tickets_neon as $row) {
    $read_tickets_neon[] = "[".$row['epoch_time'].",".$row['read_tickets']."]";
    $write_tickets_neon[] = "[".$row['epoch_time'].",".$row['write_tickets']."]"; 
}

foreach ($stmt_available_tickets_argon as $row) {
    $read_tickets_argon[] = "[".$row['epoch_time'].",".$row['read_tickets']."]";
    $write_tickets_argon[] = "[".$row['epoch_time'].",".$row['write_tickets']."]"; 
}

foreach ($stmt_available_tickets_krypton as $row) {
    $read_tickets_krypton[] = "[".$row['epoch_time'].",".$row['read_tickets']."]";
    $write_tickets_krypton[] = "[".$row['epoch_time'].",".$row['write_tickets']."]";
 }

foreach ($stmt_connections_helium as $row) {
    $connections_helium[] = "[".$row['epoch_time'].",".$row['connections']."]";
} 



foreach ($stmt_connections_neon as $row) {
    $connections_neon[] = "[".$row['epoch_time'].",".$row['connections']."]";
}  



foreach ($stmt_connections_argon as $row) {
    $connections_argon[] = "[".$row['epoch_time'].",".$row['connections']."]";
}   

foreach ($stmt_connections_krypton as $row) {
    $connections_krypton[] = "[".$row['epoch_time'].",".$row['connections']."]";
}

prof_flag("Done");

$time_end = microtime(true);
$execution_time = ($time_end - $time_start);

//execution time of the script
echo '<b>Total Execution Time:</b> '.$execution_time.' secs'; 

prof_print();
?>

该脚本的顶部是一个函数，该函数显示慢的部分。这部分的输出：

总执行时间：34.110798120499秒 开始 0.000032 连接到数据库 0.045901 执行查询 9.475136 检索数据 24.588582 完成

使用我的foreach语句检索数据部分花费的时间最多。

您有什么想法可以让我更快吗？一个查询返回大约5万至15万行。

谢谢！

解决方法

您可以通过使用

将所有查询合并为一个查询来优化代码

...WHERE host_id IN (1,2,3,4) 

或使用

UNION

这将最大程度地减少所有数据库访问开销。

4 x 50k-150k行很多，您真的一次需要它们吗？也许您可以使用批处理作业来处理它们，缓存结果并仅访问缓存？