| From: | Merlin Moncure <mmoncure(at)gmail(dot)com> |
|---|---|
| To: | Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com> |
| Cc: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, Peter Geoghegan <peter(at)2ndquadrant(dot)com>, Stefan Keller <sfkeller(at)gmail(dot)com>, pgsql-performance(at)postgresql(dot)org |
| Subject: | Re: Hash index use presently(?) discouraged since 2005: revive or bury it? |
| Date: | 2011-09-15 20:00:28 |
| Message-ID: | CAHyXU0w3e1reYpebLU93bdhwJFpRkdGBz9FhXWFW6s-Bb0sp5g@mail.gmail.com |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-performance |
On Wed, Sep 14, 2011 at 4:03 AM, Heikki Linnakangas
<heikki(dot)linnakangas(at)enterprisedb(dot)com> wrote:
> On 14.09.2011 03:24, Tom Lane wrote:
>>
>> The big picture though is that we're not going to remove hash indexes,
>> even if they're nearly useless in themselves, because hash index
>> opclasses provide the foundation for the system's knowledge of how to
>> do the datatype-specific hashing needed for hash joins and hash
>> aggregation. And those things *are* big wins, even if hash indexes
>> themselves never become so.
>
> We could drop the hash indexam code but keep the opclasses etc. I'm not sure
> that would gain us, though.
HM, what if you junked the current hash indexam, and just implemented
a wrapper over btree so that the 'hash index' was just short hand for
hashing the value into a standard index?
merlin
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Claudio Freire | 2011-09-15 20:28:50 | Re: Hash index use presently(?) discouraged since 2005: revive or bury it? |
| Previous Message | MirrorX | 2011-09-15 09:42:58 | Re: cannot use multicolumn index |