Indeed it's confusing.
最初由 nattyneat 发布
[B]oracle 对数据文件的操作是否要借助OS的IO系统?
对OS的知识了解太欠缺了,要尽快补上。
If your operating system reads the next block during sequential reads,
[/B]
this "block" is io block, or fs block, or disk block,
or db block? my understanding is db block since
it also mentioned "sequential reads"
[B]
and your
application performs many full table scans, the operating system I/O size should be
equal to or greater than the database block size.
这段不是恨明白。os 每次输入输出的时候是osblock size 的倍数 吗?难道这个倍数有时候甚至超过db_block_size(也是osblock size的倍数)呢? [/B]
io blockis the mutiples of 512 bytes,
and could as high as 1MB, 4MB, or more.
and db block sizeis 8k, 16k .....
and usually io block size is multiple of that.
The tricky thing is how to find the default io block sizeof a device. If someone know, please share.
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