Re: Hash Indexes

On 25/09/16 18:18, Amit Kapila wrote:
> On Sat, Sep 24, 2016 at 10:49 PM, Greg Stark <stark@mit.edu> wrote:
>> On Thu, Sep 22, 2016 at 3:23 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>>> But to kick the hash AM as such to the curb is to say
>>> "sorry, there will never be O(1) index lookups in Postgres".
>> Well there's plenty of halfway solutions for that. We could move hash
>> indexes to contrib or even have them in core as experimental_hash or
>> unlogged_hash until the day they achieve their potential.
>>
>> We definitely shouldn't discourage people from working on hash indexes
>>
> Okay, but to me it appears that naming it as experimental_hash or
> moving it to contrib could discourage people or at the very least
> people will be less motivated.  Thinking on those lines a year or so
> back would have been a wise direction, but now when already there is
> lot of work done (patches to make it wal-enabled, more concurrent and
> performant, page inspect module are available) for hash indexes and
> still more is in progress, that sounds like a step backward then step
> forward.
>

+1

I think so too - I've seen many email threads over the years on this 
list that essentially state "we need hash indexes wal logged to make 
progress with them"...and Amit et al has/have done this (more than this 
obviously - made 'em better too) and I'm astonished that folk are 
suggesting anything other than 'commit this great patch now!'...

regards

Mark