On Wed, Aug 23, 2017 at 11:59 PM, Amit Kapila <amit.kapil...@gmail.com> wrote:
> On Wed, Aug 23, 2017 at 11:05 AM, Haribabu Kommi > <kommi.harib...@gmail.com> wrote: > > > > > > On Mon, Aug 21, 2017 at 7:25 PM, Amit Kapila <amit.kapil...@gmail.com> > > wrote: > >> > >> On Mon, Aug 21, 2017 at 12:58 PM, Haribabu Kommi > >> <kommi.harib...@gmail.com> wrote: > >> > > >> > On Sun, Aug 13, 2017 at 5:17 PM, Amit Kapila <amit.kapil...@gmail.com > > > >> > wrote: > >> >> > >> >> > >> >> Also, it is quite possible that some of the storage Am's don't even > >> >> want to return bool as a parameter from HeapTupleSatisfies* API's. I > >> >> guess what we need here is to provide a way so that different storage > >> >> am's can register their function pointer for an equivalent to > >> >> satisfies function. So, we need to change > >> >> SnapshotData.SnapshotSatisfiesFunc in some way so that different > >> >> handlers can register their function instead of using that directly. > >> >> I think that should address the problem you are planning to solve by > >> >> omitting buffer parameter. > >> > > >> > > >> > Thanks for your suggestion. Yes, it is better to go in the direction > of > >> > SnapshotSatisfiesFunc. > >> > > >> > I verified the above idea of implementing the Tuple visibility > functions > >> > and assign them into the snapshotData structure based on the snapshot. > >> > > >> > The Tuple visibility functions that are specific to the relation are > >> > available > >> > with the RelationData structure and this structure may not be > available, > >> > > >> > >> Which functions are you referring here? I don't see anything in > >> tqual.h that uses RelationData. > > > > > > > > With storage API's, the tuple visibility functions are available with > > RelationData > > and those are needs used to update the SnapshotData structure > > SnapshotSatisfiesFunc member. > > > > But the RelationData is not available everywhere, where the snapshot is > > created, > > but it is available every place where the tuple visibility is checked. > So I > > just changed > > the way of checking the tuple visibility with the information of > snapshot by > > calling > > the corresponding tuple visibility function from RelationData. > > > > If SnapshotData provides MVCC, then the MVCC specific tuple visibility > > function from > > RelationData is called. The SnapshotSatisfiesFunc member is changed to a > > enum > > that holds the tuple visibility type such as MVCC, DIRTY, SELF and etc. > > Whenever > > the visibility check is needed, the corresponding function is called. > > > > It will be easy to understand and see if there is some better > alternative once you have something in the form of a patch. Sorry for the delay. I will submit the new patch series with all comments given in the upthread to the upcoming commitfest. Regards, Hari Babu Fujitsu Australia
