Re: Compression of full-page-writes

On Thu, Jan  1, 2015 at 10:40:53AM +0530, Amit Kapila wrote:
> Good question,  I think there might be some impact due to that, but in
> general for page level compression still there will be much more to
> compress. 
> 
> In general, I think this idea has merit with respect to compressible data,
> and to save for the cases where it will not perform well, there is a on/off
> switch for this feature and in future if PostgreSQL has some better
> compression method, we can consider the same as well.  One thing
> that we need to think is whether user's can decide with ease when to
> enable this global switch.

Yes, that is the crux of my concern.  I am worried about someone who
assumes compressions == good, and then enables it.  If we can't clearly
know when it is good, it is even harder for users to know.  If we think
it isn't generally useful until a new compression algorithm is used,
perhaps we need to wait until the we implement this.


--  Bruce Momjian  <bruce@momjian.us>        http://momjian.us EnterpriseDB
http://enterprisedb.com
 + Everyone has their own god. +