Re: Microvacuum support for Hash Index

On Wed, Mar 15, 2017 at 9:23 PM, Ashutosh Sharma <ashu(dot)coek88(at)gmail(dot)com> wrote:
>
>>
>> Few other comments:
>> 1.
>> + if (ndeletable > 0)
>> + {
>> + /* No ereport(ERROR) until changes are logged */
>> + START_CRIT_SECTION();
>> +
>> + PageIndexMultiDelete(page, deletable, ndeletable);
>> +
>> + pageopaque = (HashPageOpaque) PageGetSpecialPointer(page);
>> + pageopaque->hasho_flag &= ~LH_PAGE_HAS_DEAD_TUPLES;
>>
>> You clearing this flag while logging the action, but same is not taken
>> care during replay. Any reasons?
>
> That's because we conditionally WAL Log this flag status and when we
> do so, we take a it's FPI.
>

Sure, but we are not clearing in conditionally. I am not sure, how
after recovery it will be cleared it gets set during normal operation.
Moreover, btree already clears similar flag during replay (refer
btree_xlog_delete).

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