the allpages-locked table versus the data-only-locked table

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the allpages-locked table
the data-only-locked table

allpages-locked
data-only-locked
分别是什么意思

Rabbit...

两种不同的 lock schema, allpage lock 锁住 data page, 而data-only lock 只锁住 index he date page 的相关 rows.

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但是为什么这两个lock schema：
allpages-locked
data-only-locked
对数据库的影响差别特别大。

比如：

If an allpages-locked table is very small,so that the entire index fits on a single page,there are no intermediate or leaf levels,and the root page stores pointers to the data pages.

Data-only-locked tables always have a leaf level between the root page and the data pages.

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For  clustered indexes on apppages-locked tables,the leaf level is the data.No other level of the index contains one index row for each data row.

For nonculustered indexes and clustered indexes on data-only-locked tables,the leaf level contains the index key value for each row,a pointer to the where the row is stored,and a pointer to the rows on the data page.