Mysql使用高流量数据库上的过滤器计算行数

Let's say you have a search form, with multiple select fields, let's say a user selects from a dropdown an option, but before he submits the data I need to display the count of the rows in the database .

假设您有一个搜索表单,有多个选择字段,假设用户从下拉列表中选择一个选项,但在提交数据之前,我需要显示数据库中的行数。

So let's say the site has at least 300k(300.000) visitors a day, and a user selects options from the form at least 40 times a visit, that would mean 12M ajax requests + 12M count queries on the database, which seems a bit too much .

所以假设该网站每天至少有300k(300.000)个访问者,并且用户从访问表中选择至少40次访问的选项,这意味着12M ajax请求+ 12M计数查询数据库,这似乎有点太多了

The question is how can one implement a fast count (using php(Zend Framework) and MySQL) so that the additional 12M queries on the database won't affect the load of the site .

问题是如何实现快速计数(使用php(Zend Framework)和MySQL),以便数据库上额外的12M查询不会影响站点的负载。

One solution would be to have a table that stores all combinations of select fields and their respective counts (when a product is added or deleted from the products table the table storing the count would be updated). Although this is not such a good idea when for 8 filters (select options) out of 43 there would be +8M rows inserted that need to be managed.

一种解决方案是具有存储所选字段的所有组合及其各自计数的表(当从产品表中添加或删除产品时,将更新存储计数的表)。虽然这对于43个中的8个过滤器(选择选项)来说并不是一个好主意,但是会插入需要管理的+ 8M行。

Any other thoughts on how to achieve this?

关于如何实现这一点的任何其他想法?

p.s. I don't need code examples but the idea itself that would work in this scenario.

附:我不需要代码示例,但想法本身可以在这种情况下工作。

10 个解决方案

#1

I would suggest a separate table that caches the counts, combined with triggers.

我会建议一个单独的表来缓存计数,并结合触发器。

In order for it to be fast you make it a memory table and you update it using triggers on the inserts, deletes and updates.

为了使它快速,你可以使它成为一个内存表,并使用插入,删除和更新的触发器来更新它。

pseudo code:

CREATE TABLE counts (
  id unsigned integer auto_increment primary key
  option integer indexed using hash key
  user_id integer indexed using hash key
  rowcount unsigned integer
  unique key user_option (user, option)
) engine = memory

DELIMITER $$

CREATE TRIGGER ai_tablex_each AFTER UPDATE ON tablex FOR EACH ROW
BEGIN
  IF (old.option <> new.option) OR (old.user_id <> new.user_id) THEN BEGIN
    UPDATE counts c SET c.rowcount = c.rowcount - 1 
      WHERE c.user_id = old.user_id and c.option = old.option; 
    INSERT INTO counts rowcount, user_id, option  
      VALUES (1, new.user_id, new.option)
      ON DUPLICATE KEY SET c.rowcount = c.rowcount + 1; 
  END; END IF;
END $$

DELIMITER ;

Selection of the counts will be instant, and the updates in the trigger should not take very long either because you're using a memory table with hash indexes which have O(1) lookup time.

计数的选择将是即时的,并且触发器中的更新不会花费很长时间,因为您正在使用具有O(1)查找时间的哈希索引的内存表。

Links:
Memory engine: http://dev.mysql.com/doc/refman/5.5/en/memory-storage-engine.html
Triggers: http://dev.mysql.com/doc/refman/5.5/en/triggers.html

链接:内存引擎:http://dev.mysql.com/doc/refman/5.5/en/memory-storage-engine.html触发器:http://dev.mysql.com/doc/refman/5.5/en/ triggers.html

10 个解决方案

#1

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