FIle and Block size relationships ...

[Alma J Wetzker]

Ben Duncan wrote:
> Ok, another question ....
> 
> Should I make the POINTERS to blocks or make them the
> actual lseek pointers?
> 
> What I mean, a reference pointer to a block address
> would always be block number times 512 (my default page/block size)
> versus the actual disk address ?
> 
> FWIW, all nodes (interior / leaf ) and data blocks will always be
> a 512 byte page size ...
> 
> The difference is that I would have to use either 8 byte (64 bit 
> addressing)
> versus 4 byte (32 bit) times 512. The cost savings would be
> using 32 bit times block would shave 4 bytes off my node layout for
> each key/item pair but require CPU time to calc it ...
> 
> Thanks ...
> 
> Bill Campbell wrote:
> 
>>
>> Yup.  The block size is the minimum amount of space a file will
>> take on disk.
>>
>> As far as I know, this is pretty much any kind of file system.
>> although it's not as noticeable on *nix file systems as it is on
>> Microsoft DOS style file systems which have other limitations on
>> the numbers of entries in FAT tables and such which makes things
>> very ``intersting'' when dealing with large file systems where
>> the block sizes get truly humongous.
>>

I don't understand.  Are you asking if you should store the actual block 
on the disk?  That would go back to Oracle's raw file system type of 
stuff, a real headache, but fast.  How would you handle backup and 
restore?  Reloading data?

     -- Alma