> On 19 Jun 2018, at 12:40, Alexander Korotkov <a(dot)korotkov(at)postgrespro(dot)ru> wrote:
>
> On Tue, Jun 19, 2018 at 12:15 PM Alexander Korotkov
> <a(dot)korotkov(at)postgrespro(dot)ru> wrote:
>> On Sat, Jun 16, 2018 at 3:57 PM Darafei "Komяpa" Praliaskouski
>> <me(at)komzpa(dot)net> wrote:
>>>>
>>>>> I'm not sure it is usefull in release notes since it is more about API, and not
>>>>> user-facing change. Just in case.
>>>>> GiST opclasses now can omit compress and decompress functions. If compress
>>>>> function is omited, IndexOnlyScan is enabled for opclass without any extra
>>>>> change.
>>>>> https://github.com/postgres/postgres/commit/
>>>>> d3a4f89d8a3e500bd7c0b7a8a8a5ce1b47859128
>>>>
>>>> Uh, we do have this for SP-GiST:
>>>>
>>>> Allow SP-GiST indexes to optionally use compression (Teodor Sigaev,
>>>> Heikki Linnakangas, Alexander Korotkov, Nikita Glukhov)
>>>>
>>>> I am unclear how far downt the API stack I should go in documenting
>>>> changes like this.
>>>
>>>
>>> It is also a bit misleading - the idea in that change is that now index representation can be a lossy version of actual data type (a box instead of polygon as a referende, so a changelog entry can tell "Allow SP-GiST index creation for polygon datatype."). There is no "decompression" for such thing. "compression" sounds like gzip for me in user-facing context.
>>
>> +1 that current wording looks confusing. But I think we need to
>> highlight that we have general SP-GiST improvement, not just support
>> for particular datatype. So, I propose following wording: "Allow
>> SP-GiST to use lossy representation of leaf keys, and add SP-GiST
>> support for polygon type using that".
>
> Oh, I missed that we have separate release notes entry for polygons
> indexing. Then second part of sentence isn't needed, it should be
> just "Allow SP-GiST to use lossy representation of leaf keys". If no
> objections, I'm going to commit that altogether with fixes by
> Liudmila.
Speaking of typos, I think I spotted two more: s/features is/feature is/.
Fixed in the attached diff.
cheers ./daniel