Re: Setting pd_lower in GIN metapage

On Wed, Sep 20, 2017 at 9:19 AM, Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
> On Wed, Sep 20, 2017 at 4:25 AM, Michael Paquier
> <michael(dot)paquier(at)gmail(dot)com> wrote:
>> On Wed, Sep 20, 2017 at 12:47 AM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>>> Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> writes:
>>>> On Tue, Sep 19, 2017 at 9:27 AM, Michael Paquier
>>>> <michael(dot)paquier(at)gmail(dot)com> wrote:
>>>>> I am not saying that no index AMs take advantage FPW compressibility
>>>>> for their meta pages. There are cases like this one, as well as one
>>>>> code path in BRIN where this is useful, and it is useful as well when
>>>>> logging FPWs of the init forks for unlogged relations.
>>>
>>>> Hmm, why is it useful for logging FPWs of the init forks for unlogged
>>>> relations? We don't use REGBUF_STANDARD in those cases.
>>>
>>> But if we started to do so, that would be a concrete benefit of this
>>> patch ...
>>
>> In the proposed set of patches, all the empty() routines part of index
>> AMs which use log_newpage_buffer() (brin, gin, spgst) are doing the
>> right thing by updating log_newpage_buffer(). btree also should have
>> its call to log_newpage updated in btbuildempty(), and your patch is
>> missing that.
>>
>
> We can add that for btree patch.
>

Added and updated the comments for both btree and hash index patches.

--
With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com