Re: Query on DB block size

>can anyone explain this for me ? I have a Oracle RDBMS server on Unix.
>Now, it so happens that my Unix block size is 8K and the DB block size
>is 4K. Does it result in space wastage or more I/O ? Why does Oracle say
>that the Oracle DB block size has to be equal to or multiples of the OS
>block size ? Could somebody please explain the relation between the OS
>block size and DB block size.

Oracle cannot store data belonging to different Oracle blocks in one OS blocks. (It can store data belonging to one block in more than one OS block) This means that all space in an OS block that is not occupied by a DB block is wasted.
If your OS block size is 8k and your DB block size is 4k, you will waste 4k of each OS block. On the other hand, if your OS block size is 8k and your DB block size is 12k, you will waste 4k of each second OS block.

Stefan.

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