Re: Write Ahead Logging for Hash Indexes

On Thu, Dec 1, 2016 at 9:44 PM, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
> On Thu, Dec 1, 2016 at 1:03 AM, Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
>> On Wed, Nov 9, 2016 at 7:40 PM, Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
>>> On Tue, Nov 8, 2016 at 10:56 PM, Jeff Janes <jeff(dot)janes(at)gmail(dot)com> wrote:
>>>> Unless we want to wait until that work is committed before doing more review
>>>> and testing on this.
>>>
>>> The concurrent hash index patch is getting changed and some of the
>>> changes needs change in this patch as well. So, I think after it gets
>>> somewhat stabilized, I will update this patch as well.
>>
>> Now that concurrent hash index patch is committed [1], I will work on
>> rebasing this patch. Note, I have moved this to next CF.
>
> Thanks. I am thinking that it might make sense to try to get the
> "microvacuum support for hash index" and "cache hash index meta page"
> patches committed before this one, because I'm guessing they are much
> simpler than this one, and I think therefore that the review of those
> patches can probably move fairly quickly.
>

I think it makes sense to move "cache hash index meta page" first,
however "microvacuum support for hash index" is based on WAL patch as
the action in this patch (delete op) also needs to be logged. One
idea could be that we can try to split the patch so that WAL logging
can be done as a separate patch, but I am not sure if it is worth.

> Of course, ideally I can
> also start reviewing this one in the meantime. Does that make sense
> to you?
>

You can start reviewing some of the operations like "Create Index",
"Insert". However, some changes are required because of change in
locking strategy for Vacuum. I am planning to work on rebasing it and
making required changes in next week.

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