Re: pageinspect and hash indexes

On Sat, Mar 18, 2017 at 12:12 AM, Ashutosh Sharma <ashu(dot)coek88(at)gmail(dot)com> wrote:
> On Fri, Mar 17, 2017 at 10:54 PM, Jeff Janes <jeff(dot)janes(at)gmail(dot)com> wrote:
>> While trying to figure out some bloating in the newly logged hash indexes,
>> I'm looking into the type of each page in the index. But I get an error:
>>
>> psql -p 9876 -c "select hash_page_type(get_raw_page('foo_index_idx',x)) from
>> generate_series(1650,1650) f(x)"
>>
>> ERROR: page is not a hash page
>> DETAIL: Expected 0000ff80, got 00000000.
>>
>> The contents of the page are:
>>
>> \xa4000000d8f203bf65c900001800f01ff01f0420...
>>
>> (where the elided characters at the end are all zero)
>>
>> What kind of page is that actually?
>
> it is basically either a newly allocated bucket page or a freed overflow page.
>

What makes you think that it can be a newly allocated page?
Basically, we always initialize the special space of newly allocated
page, so not sure what makes you deduce that it can be newly allocated
page.

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