Re: old_snapshot_threshold's interaction with hash index

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.



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