Re: GIN improvements part 1: additional information

On Mon, Dec 9, 2013 at 1:18 PM, Heikki Linnakangas
<hlinnakangas(at)vmware(dot)com>wrote:

> On 12/08/2013 09:56 PM, Alexander Korotkov wrote:
>
>> On Fri, Nov 29, 2013 at 11:17 PM, Heikki Linnakangas <
>> hlinnakangas(at)vmware(dot)com> wrote:
>>
>> I'll continue reviewing next week..
>>>
>>
> Got dragged into other things and didn't make any progress on this last
> week. I'm trying again now.
>
>
> Good. Thanks for debug and fixing bugs.
>> Can I do anything for this patch now?
>>
>
> I wonder if we're leaving some money on the table, by using varbyte
> encoding. Googling around, there are many other compression methods out
> there for compressing integer deltas that compress better, and/or
> decompress faster.
>

Ok, I'll try to google around. Probably, there are some better options.

> Even if we use varbyte encoding, I wonder if it would be better to treat
> block + offset number as a single 48-bit integer, rather than encode them
> separately. That would allow the delta of two items on the same page to be
> stored as a single byte, rather than two bytes. Naturally it would be a
> loss on other values, but would be nice to see some kind of an analysis on
> that. I suspect it might make the code simpler, too.

Yeah, I had that idea, but I thought it's not a better option. Will try to
do some analysis.

------
With best regards,
Alexander Korotkov.