Re: old_snapshot_threshold's interaction with hash index

On Sun, May 1, 2016 at 1:43 AM, Amit Kapila <amit.kapila16@gmail.com> wrote:
> On Sun, May 1, 2016 at 12:05 PM, Amit Kapila <amit.kapila16@gmail.com> wrote:
>>
>> Currently we do the test for old snapshot (TestForOldSnapshot) for hash
>> indexes while scanning them.  Does this test makes any sense for hash
>> indexes considering LSN on hash index will always be zero (as hash indexes
>> are not WAL-logged)?  It seems to me that PageLSN check in
>> TestForOldSnapshot() will always return false which means that the error
>> "snapshot too old" won't be generated for hash indexes.
>>
>> Am I missing something here, if not, then I think we need a way to
>> prohibit pruning for hash indexes based on old_snapshot_threshold?
>
> What I mean to say here is prohibit pruning the relation which has hash
> index based on old_snapshot_threshold.

Good spot; added to the open issues page.

Thanks!

-- 
Kevin Grittner
EDB: http://www.enterprisedb.com
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