用MySQL管理大数据

By the end of this course,you will be able to

1.Describe the structure of relational databases,

2.Interpret and create entity relationship diagrams and relational schamas that describe the contents of specific criteria, and retrieve such data from MySQL an teradata databases that contain over one million rows of data.

3.Execute practices that limit the impact of your queries on other coworkers.

4. Summarize rows of data using aggregate function and segment aggregations according to specified variables.

5. Combine and manipulate data from multiple tables, across a database.

6.Retrieve records and compute calculations that are dependent on dynamic data features. And translate data analysis questions into SQL queries.

查询大量数据的,如果出现如下情况,就说明最大内存已经耗尽:

可临时修改脚本使用内存大小进行处理:

注意：

当使用libmysqlclient作为库时，PHP的内存限制将不会计算用于结果集的内存，除非将数据读入PHP变量。与mysqlnd的内存占用将包括完整的结果集。

由于缓冲查询是默认的，下面的示例将演示如何使用每个API执行无缓冲的查询。

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