Mysql的页面外是什么? [英] What is off page in Mysql?

问题描述

在Innodb Engine中使用 text 和 blob 数据类型列时.该字段中存储的值存储在页面外而不存储在页面中(Innodb页面的默认大小为16kb).

When the text and blob data type column is used in Innodb Engine. The value which are stored in that field is stored in off-page not stored in page (The default Size of Innodb page is 16kb).

我的问题是 1.页外是什么意思? 2.从页外检索值时如何访问它?

My Questions are 1. What is the off-page mean? 2. How its is accessed while retrieving the value from off-page?

推荐答案

1. 页面外的意思是什么

我的意思是它存储在单独的区域中，因此它不会膨胀主索引.这样，页面的大小可以保持相同且精确(其他类型所需的确切存储空间是已知的)，并且可以更快地访问数据.

I means that it is stored in a separate area, so it doesn't bloat the main index. This way, the size of the pages can stay identical and exact (the exact storage space required for everything other types is known), and it makes accessing the data faster.

1. 从页外检索值时如何访问它?

存储了一个20字节的指针，它包含该列其余部分的地址.

A 20-byte pointer is stored and it contains the address of the rest of the column.

PS.我认为这个问题更适合 DBA

PS. I think this question would be better suited for DBA

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