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  • MySQL 的 read_buffer_size 参数是如何影响写缓冲和写性能的?

    Each thread // that does a sequential scan for a MyISAM table// allocates a buffer of this size (in bytes) for each table it scans. 

    If you do many sequential scans, you might want to increase this value, which defaults to 131072. The value of this variable should be a multiple of 4KB. If

    it is set to a value that is not a multiple of 4KB, its value will be rounded down to the nearest multiple of 4KB. This option is also used in the following context for all storage engines: For caching the indexes in a temporary file (not a temporary table), when sorting rows for ORDER BY.
    用于缓存临时表索引---order by For bulk insert into partitions.
    批量插入到分区 For caching results of nested queries.
    嵌套查询的结果集

    read_buffer_size 设置以顺序扫描的方式扫描表数据的时候使用缓冲区的大小.
    每个线程进行顺序扫描的时候都会产生该buffer ,而且同一个Query中如果有多个表进行全表扫描,会产生多个该buffer.

     

     How read_buffer_size Impacts Write Buffering and Write Performance

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  • 原文地址:https://www.cnblogs.com/zengkefu/p/5600118.html
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