Re: Cache Hash Index meta page.

On Thu, Dec 22, 2016 at 12:17 PM, Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
> On Wed, Dec 21, 2016 at 9:26 PM, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
>> On Tue, Dec 20, 2016 at 2:25 PM, Mithun Cy <mithun(dot)cy(at)enterprisedb(dot)com> wrote:
>>> -- I think if it is okay, I can document same for each member of HashMetaPageData whether to read from cached from meta page or directly from current meta page. Below briefly I have commented for each member. If you suggest I can go with that approach, I will produce a neat patch for same.
>>
>> Plain text emails are preferred on this list.

Sorry, I have set the mail to plain text mode now.

> I think this will make metpage cache access somewhat
> similar to what we have in btree where we use cache to access
> rootpage. Will something like that address your concern?

Thanks, just like _bt_getroot I am introducing a new function
_hash_getbucketbuf_from_hashkey() which will give the target bucket
buffer for the given hashkey. This will use the cached metapage
contents instead of reading meta page buffer if cached data is valid.
There are 2 places which can use this service 1. _hash_first and 2.
_hash_doinsert.

--
Thanks and Regards
Mithun C Y
EnterpriseDB: http://www.enterprisedb.com