Multiple Block Sizes (53)

最新推荐文章于 2025-12-17 14:20:19 发布
转载 最新推荐文章于 2025-12-17 14:20:19 发布 · 179 阅读 · 0
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#数据库

本文介绍了Oracle数据库中块大小的配置方法及重要性。标准块大小由DB_BLOCK_SIZE参数控制，范围从2K到32K。文章还提到，可以在初始化参数文件中为不同大小的块配置子缓存，并且所有分区对象必须位于相同块大小的表空间内。

Oracle supports multiple block sizes in a database. The standard block size is used for
the SYSTEM tablespace. This is set when the database is created and can be any valid
size. You specify the standard block size by setting the initialization parameter
DB_BLOCK_SIZE. Legitimate values are from 2K to 32K.
In the initialization parameter file or server parameter, you can configure subcaches
within the buffer cache for each of these block sizes. Subcaches can also be configured
while an instance is running. You can create tablespaces having any of these block
sizes. The standard block size is used for the system tablespace and most other
tablespaces.
Note: All partitions of a partitioned object must reside in tablespaces
of a single block size.

多样的块值大小
1. 有DB_BLOCK_SIZE初始参数控制标准的块大小 ， 2K to 32K为合法的值
2. 分区对象只能是单一的块值

[@more@]

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转载于:http://blog.itpub.net/10599713/viewspace-975629/

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Negative error codes // are propagated to the user. // May return LFS_ERR_CORRUPT if the block should be considered bad. int (*erase)(const struct lfs_config *c, lfs_block_t block); // Sync the state of the underlying block device. Negative error codes // are propagated to the user. int (*sync)(const struct lfs_config *c); #ifdef LFS_THREADSAFE // Lock the underlying block device. Negative error codes // are propagated to the user. int (*lock)(const struct lfs_config *c); // Unlock the underlying block device. Negative error codes // are propagated to the user. int (*unlock)(const struct lfs_config *c); #endif // Minimum size of a block read in bytes. All read operations will be a // multiple of this value. lfs_size_t read_size; // Minimum size of a block program in bytes. All program operations will be // a multiple of this value. lfs_size_t prog_size; // Size of an erasable block in bytes. This does not impact ram consumption // and may be larger than the physical erase size. 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