Steve Atkins wrote:
>
> On Oct 29, 2008, at 9:50 PM, Grant Allen wrote:
>>
>>
>> One other thing I forgot to mention: Compression by the DB trumps
>> filesystem compression in one very important area - shared_buffers!
>> (or buffer_cache, bufferpool or whatever your favourite DB calls its
>> working memory for caching data). Because the data stays compressed
>> in the block/page when cached by the database in one of its buffers,
>> you get more bang for you memory buck in many circumstances! Just
>> another angle to contemplate :-)
>
> The additional latency added by decompression is reasonably small
> compared with traditional disk access time. It's rather large compared
> to memory access time.
The one place where Compression is an immediate benefit is the wire. It
is easy to forget that one of our number one bottlenecks (even at
gigabit) is the amount of data we are pushing over the wire.
Joshua D. Drake
>
> Cheers,
> Steve
>
>