Re: jsonb format is pessimal for toast compression - Mailing list pgsql-hackers

From Claudio Freire
Subject Re: jsonb format is pessimal for toast compression
Date
Msg-id CAGTBQpZYr+QVrN+eH5r34vVuF4QW9ciXjCgkmNWMd21bg+TYrA@mail.gmail.com
Whole thread Raw
In response to Re: jsonb format is pessimal for toast compression  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
On Tue, Aug 26, 2014 at 4:01 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Josh Berkus <josh@agliodbs.com> writes:
>> On 08/26/2014 11:40 AM, Tom Lane wrote:
>>> I was hoping you'd get some useful data from that, but so far it seems
>>> like a rehash of points made in the on-list thread :-(
>
>> Unfortunately even the outside commentors don't seem to understand that
>> storage size *is* related to speed, it's exchanging I/O speed for CPU speed.
>
> Yeah, exactly.  Given current hardware trends, data compression is
> becoming more of a win not less as time goes on: CPU cycles are cheap
> even compared to main memory access, let alone mass storage.  So I'm
> thinking we want to adopt a compression-friendly data format even if
> it measures out as a small loss currently.
>
> I wish it were cache-friendly too, per the upthread tangent about having
> to fetch keys from all over the place within a large JSON object.


What about my earlier proposal?

An in-memory compressed representation would greatly help cache
locality, more so if you pack keys as you mentioned.



pgsql-hackers by date:

Previous
From: Tom Lane
Date:
Subject: Re: jsonb format is pessimal for toast compression
Next
From: Andres Freund
Date:
Subject: Re: jsonb format is pessimal for toast compression