> В Вт., 27/09/2011 в 10:23 +0200, Dimitry Sibiryakov пишет:
>> 27.09.2011 10:18, Thomas Steinmaurer wrote:
>>>> Records are already compressed as delta + RLE. Page level compression is pointless
>>>> because page of variable size is a headache.
>>>
>>> Still fixed page size on disk with compressed data.
>>
>> And this is exactly why page compression is pointless: you are writing to disk full
>> page size anyway, no difference between page with uncompressed data and page with
>> compressed data + some filling zeros.
>>
>
> Must say that for example NTFS supports writing compressed pages to disk
> and does not fill it with 0, instead puts more data to the page. We
> probably can do something like this - when adding new record/version to
> the page compress it and when result does not fit, use another page for
> that record/version.

I don't know what algorith is used here, but AFAIK it decompress stuff
before going over the network etc ...

Regards,
Thomas