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.
Cheers,
Steve