Php 如何提高MySQL查询执行速度
您必须填写表格1至1000000:Php 如何提高MySQL查询执行速度,php,mysql,sql,sql-insert,recursive-query,Php,Mysql,Sql,Sql Insert,Recursive Query,您必须填写表格1至1000000: Table view CREATE TABLE `test` ( `id` INT UNSIGNED NOT NULL AUTO_INCREMENT , `value` INT UNSIGNED NOT NULL , PRIMARY KEY (`id`)) ENGINE = InnoDB;" 我写了一个函数来实现这一点,但是向表中添加数据太慢了,如何提高插入数据的性能 function InsertData(){ global $MySQ
Table view
CREATE TABLE `test` ( `id` INT UNSIGNED NOT NULL AUTO_INCREMENT , `value` INT UNSIGNED NOT NULL , PRIMARY KEY (`id`)) ENGINE = InnoDB;"
我写了一个函数来实现这一点,但是向表中添加数据太慢了,如何提高插入数据的性能
function InsertData(){
global $MySQL;
for($i = 1; $i != 1000000; $i++){
$MySQL->query("INSERT INTO `name` (`id`, `value`) VALUES ($i, $i);");
}
$MySQL->close();
}
使用递归CTE将逻辑移到数据库中如何
insert into name (id, value)
with recursive cte as (
select 1 id
union all select id + 1 from cte where i < 1000000
)
select id, id from cte
这可能需要使用递归同时生成许多行。另一种方法是只生成10行,然后将这些行相乘:
insert into name (id, value)
with recursive cte as (
select 0 id
union all select id + 1 from cte where i < 9
)
select id, id
from (
select 1 + c0.id + c1.id * 10 + c2.id * 100 + c3.id * 1000 + c4.id * 10000 + c5.id * 100000 id
cte c0
cross join cte c1
cross join cte c2
cross join cte c3
cross join cte c4
cross join cte c5
) t
使用递归CTE将逻辑移到数据库中如何
insert into name (id, value)
with recursive cte as (
select 1 id
union all select id + 1 from cte where i < 1000000
)
select id, id from cte
这可能需要使用递归同时生成许多行。另一种方法是只生成10行,然后将这些行相乘:
insert into name (id, value)
with recursive cte as (
select 0 id
union all select id + 1 from cte where i < 9
)
select id, id
from (
select 1 + c0.id + c1.id * 10 + c2.id * 100 + c3.id * 1000 + c4.id * 10000 + c5.id * 100000 id
cte c0
cross join cte c1
cross join cte c2
cross join cte c3
cross join cte c4
cross join cte c5
) t
您可以使用事务,以便每数千次插入只提交一次,或者,如果您勇敢的话,在数百万次查询之后提交一次。下面是一个勇敢的例子:
function InsertData(){
global $MySQL;
// Start transactions
$MySQL->query('SET autocommit=0;');
$MySQL->query('START TRANSACTION;');
for($i = 1; $i != 1000000; $i++){
$MySQL->query("INSERT INTO `name` (`id`, `value`) VALUES ($i, $i);");
}
// So far, nothing as actually been saved to database
// Commit all inserts.
$MySQL->query('COMMIT;');
$MySQL->query('SET autocommit=1;');
$MySQL->close();
}
如果由于某些MySQL限制,这对于单个事务来说太多,您可以每隔大约10000次插入执行一次提交:
function InsertData(){
global $MySQL;
// Start transactions
$MySQL->query('SET autocommit=0;');
$MySQL->query('START TRANSACTION;');
for($i = 1; $i != 1000000; $i++){
$MySQL->query("INSERT INTO `name` (`id`, `value`) VALUES ($i, $i);");
if($i % 10000 == 0) {
$MySQL->query('COMMIT;');
$MySQL->query('START TRANSACTION;');
}
}
// So far, nothing as actually been saved to database
// Commit all inserts.
$MySQL->query('COMMIT;');
$MySQL->query('SET autocommit=1;');
$MySQL->close();
}
请注意最终限制->
当然,这是一个实验或一次脚本。不建议在生产数据库中执行此操作。您可以使用事务,以便每数千次插入只提交一次,或者,如果您勇敢的话,在数百万次查询之后提交一次。下面是一个勇敢的例子:
function InsertData(){
global $MySQL;
// Start transactions
$MySQL->query('SET autocommit=0;');
$MySQL->query('START TRANSACTION;');
for($i = 1; $i != 1000000; $i++){
$MySQL->query("INSERT INTO `name` (`id`, `value`) VALUES ($i, $i);");
}
// So far, nothing as actually been saved to database
// Commit all inserts.
$MySQL->query('COMMIT;');
$MySQL->query('SET autocommit=1;');
$MySQL->close();
}
如果由于某些MySQL限制,这对于单个事务来说太多,您可以每隔大约10000次插入执行一次提交:
function InsertData(){
global $MySQL;
// Start transactions
$MySQL->query('SET autocommit=0;');
$MySQL->query('START TRANSACTION;');
for($i = 1; $i != 1000000; $i++){
$MySQL->query("INSERT INTO `name` (`id`, `value`) VALUES ($i, $i);");
if($i % 10000 == 0) {
$MySQL->query('COMMIT;');
$MySQL->query('START TRANSACTION;');
}
}
// So far, nothing as actually been saved to database
// Commit all inserts.
$MySQL->query('COMMIT;');
$MySQL->query('SET autocommit=1;');
$MySQL->close();
}
请注意最终限制->
当然,这是一个实验或一次脚本。不建议在生产数据库中执行此操作。尝试此查询:
INSERT INTO `test` (`id`, `value`)
SELECT @row := @row + 1 AS row, @row
FROM (SELECT 0 UNION SELECT 1 UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 UNION SELECT 5 UNION SELECT 6 UNION SELECT 7 UNION SELECT 8 UNION SELECT 9) AS t1,
(SELECT 0 UNION SELECT 1 UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 UNION SELECT 5 UNION SELECT 6 UNION SELECT 7 UNION SELECT 8 UNION SELECT 9) AS t2,
(SELECT 0 UNION SELECT 1 UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 UNION SELECT 5 UNION SELECT 6 UNION SELECT 7 UNION SELECT 8 UNION SELECT 9) AS t3,
(SELECT 0 UNION SELECT 1 UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 UNION SELECT 5 UNION SELECT 6 UNION SELECT 7 UNION SELECT 8 UNION SELECT 9) AS t4,
(SELECT 0 UNION SELECT 1 UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 UNION SELECT 5 UNION SELECT 6 UNION SELECT 7 UNION SELECT 8 UNION SELECT 9) AS t5,
(SELECT 0 UNION SELECT 1 UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 UNION SELECT 5 UNION SELECT 6 UNION SELECT 7 UNION SELECT 8 UNION SELECT 9) AS t6,
(SELECT @row:=0) AS nums;
这是插入到。。。选择SELECT语句本身正在生成一百万行的语句类型,其中填充了对1、1、2、2等。下面是它的工作原理:
表t1、t2、t3、t4、t5、t6各为10行。交叉连接它们会生成10^6=1000000个组合,因此生成的表将包含一百万行;
对于每一行,我们选择@row变量两次。不仅如此,我们还用1来增加它;
nums表仅用于在开始时将变量初始化为0;
生成的表被传递给INSERT语句,数据存储在表中。
一个看起来更干净的解决方案是将递归CTE与较新的MySQL/MariaDB结合使用。它是:
根据我的测试,速度有点慢。我没有监视内存使用情况。请尝试以下查询:
INSERT INTO `test` (`id`, `value`)
SELECT @row := @row + 1 AS row, @row
FROM (SELECT 0 UNION SELECT 1 UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 UNION SELECT 5 UNION SELECT 6 UNION SELECT 7 UNION SELECT 8 UNION SELECT 9) AS t1,
(SELECT 0 UNION SELECT 1 UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 UNION SELECT 5 UNION SELECT 6 UNION SELECT 7 UNION SELECT 8 UNION SELECT 9) AS t2,
(SELECT 0 UNION SELECT 1 UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 UNION SELECT 5 UNION SELECT 6 UNION SELECT 7 UNION SELECT 8 UNION SELECT 9) AS t3,
(SELECT 0 UNION SELECT 1 UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 UNION SELECT 5 UNION SELECT 6 UNION SELECT 7 UNION SELECT 8 UNION SELECT 9) AS t4,
(SELECT 0 UNION SELECT 1 UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 UNION SELECT 5 UNION SELECT 6 UNION SELECT 7 UNION SELECT 8 UNION SELECT 9) AS t5,
(SELECT 0 UNION SELECT 1 UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 UNION SELECT 5 UNION SELECT 6 UNION SELECT 7 UNION SELECT 8 UNION SELECT 9) AS t6,
(SELECT @row:=0) AS nums;
这是插入到。。。选择SELECT语句本身正在生成一百万行的语句类型,其中填充了对1、1、2、2等。下面是它的工作原理:
表t1、t2、t3、t4、t5、t6各为10行。交叉连接它们会生成10^6=1000000个组合,因此生成的表将包含一百万行;
对于每一行,我们选择@row变量两次。不仅如此,我们还用1来增加它;
nums表仅用于在开始时将变量初始化为0;
生成的表被传递给INSERT语句,数据存储在表中。
一个看起来更干净的解决方案是将递归CTE与较新的MySQL/MariaDB结合使用。它是:
根据我的测试,速度有点慢。我没有监控内存使用情况。不幸的是,我不能在5秒以上使用MySQL递归解决方案很好-它与我在下面发布的变量方法相当递归只是稍微慢了一点:8秒,而我的计算机上是6.5秒。然而,第二个非常慢,1分钟18秒。不幸的是,我不能在5秒以上使用MySQL递归解决方案很好-它与我在下面发布的变量方法相比,递归只是慢了一点:8秒,而我的计算机上是6.5秒。然而,第二个是非常缓慢的1分18秒。