Horton

Re: Pluggable Storage - Andres's take

Haribabu Kommi <kommi.haribabu@gmail.com>

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From: Haribabu Kommi <kommi.haribabu@gmail.com>
To: Andres Freund <andres@anarazel.de>
Cc: Asim R P <apraveen@pivotal.io>, Pg Hackers <pgsql-hackers@postgresql.org>, Ashwin Agrawal <aagrawal@pivotal.io>, Dmitry Dolgov <9erthalion6@gmail.com>, Alvaro Herrera <alvherre@2ndquadrant.com>, Alexander Korotkov <a.korotkov@postgrespro.ru>
Date: 2019-01-22T02:43:36Z
Lists: pgsql-hackers

Attachments

On Tue, Jan 22, 2019 at 12:15 PM Andres Freund <andres@anarazel.de> wrote:

> Hi,
>
> Thanks!
>
> On 2019-01-22 11:51:57 +1100, Haribabu Kommi wrote:
> > Attached the patch for removal of scan_update_snapshot
> > and also the rebased patch of reduction in use of t_tableOid.
>
> I'll soon look at the latter.
>

Thanks.


>
> > > - consider removing table_gimmegimmeslot()
> > > - add substantial docs for every callback
> > >
> >
> > Will work on the above two.
>
> I think it's easier if I do the first, because I can just do it while
> rebasing, reducing unnecessary conflicts.
>
>
OK. I will work on the doc changes.


> > > While I saw an initial attempt at writing smgl docs for the table AM
> > > API, I'm not convinced that's the best approach.  I think it might make
> > > more sense to have high-level docs in sgml, but then do all the
> > > per-callback docs in tableam.h.
> > >
> >
> > OK, I will update the sgml docs accordingly.
> > Index AM has per callback docs in the sgml, refactor them also?
>
> I don't think it's a good idea to tackle the index docs at the same time
> - this patchset is already humongously large...
>

OK.


>
> > diff --git a/src/backend/access/heap/heapam_handler.c
> b/src/backend/access/heap/heapam_handler.c
> > index 62c5f9fa9f..3dc1444739 100644
> > --- a/src/backend/access/heap/heapam_handler.c
> > +++ b/src/backend/access/heap/heapam_handler.c
> > @@ -2308,7 +2308,6 @@ static const TableAmRoutine heapam_methods = {
> >       .scan_begin = heap_beginscan,
> >       .scan_end = heap_endscan,
> >       .scan_rescan = heap_rescan,
> > -     .scan_update_snapshot = heap_update_snapshot,
> >       .scan_getnextslot = heap_getnextslot,
> >
> >       .parallelscan_estimate = table_block_parallelscan_estimate,
> > diff --git a/src/backend/executor/nodeBitmapHeapscan.c
> b/src/backend/executor/nodeBitmapHeapscan.c
> > index 59061c746b..b48ab5036c 100644
> > --- a/src/backend/executor/nodeBitmapHeapscan.c
> > +++ b/src/backend/executor/nodeBitmapHeapscan.c
> > @@ -954,5 +954,9 @@ ExecBitmapHeapInitializeWorker(BitmapHeapScanState
> *node,
> >       node->pstate = pstate;
> >
> >       snapshot = RestoreSnapshot(pstate->phs_snapshot_data);
> > -     table_scan_update_snapshot(node->ss.ss_currentScanDesc, snapshot);
> > +     Assert(IsMVCCSnapshot(snapshot));
> > +
> > +     RegisterSnapshot(snapshot);
> > +     node->ss.ss_currentScanDesc->rs_snapshot = snapshot;
> > +     node->ss.ss_currentScanDesc->rs_temp_snap = true;
> >  }
>
> I was rather thinking that we'd just move this logic into
> table_scan_update_snapshot(), without it invoking a callback.
>

OK. Changed accordingly.
But the table_scan_update_snapshot() function is moved into tableam.c,
to avoid additional header file snapmgr.h inclusion in tableam.h

Regards,
Haribabu Kommi
Fujitsu Australia

Commits

  1. Add default_table_access_method to postgresql.conf.sample.

  2. tableam: Avoid relying on relation size to determine validity of tids.

  3. tableam: Don't assume that every AM uses md.c style storage.

  4. Allow pg_class xid & multixid horizons to not be set.

  5. Fix slot type issue for fuzzy distance index scan over out-of-core table AM.

  6. tableam: comment and formatting fixes.

  7. table: docs: fix typos and grammar.

  8. tableam: basic documentation.

  9. Only allow heap in a number of contrib modules.

  10. tableam: Add table_finish_bulk_insert().

  11. tableam: sample scan.

  12. tableam: bitmap table scan.

  13. tableam: Move heap specific logic from estimate_rel_size below tableam.

  14. tableam: VACUUM and ANALYZE support.

  15. tableam: relation creation, VACUUM FULL/CLUSTER, SET TABLESPACE.

  16. tableam: Support for an index build's initial table scan(s).

  17. tableam: Add table_get_latest_tid, to wrap heap_get_latest_tid.

  18. tableam: Add helper for indexes to check if a corresponding table tuples exist.

  19. tableam: Add and use table_fetch_row_version().

  20. tableam: Use in CREATE TABLE AS and CREATE MATERIALIZED VIEW.

  21. Ensure sufficient alignment for ParallelTableScanDescData in BTShared.

  22. Don't reuse slots between root and partition in ON CONFLICT ... UPDATE.

  23. Use a virtual rather than a heap slot in two places where that suffices.

  24. Store tuples for EvalPlanQual in slots, rather than as HeapTuples.

  25. Use slots in trigger infrastructure, except for the actual invocation.

  26. Store table oid and tuple's tid in tuple slots directly.

  27. Allow to use HeapTupleData embedded in [Buffer]HeapTupleTableSlot.

  28. Add ExecStorePinnedBufferHeapTuple.

  29. Add ArchiveOpts to pass options to ArchiveEntry

  30. Rename RelationData.rd_amroutine to rd_indam.

  31. Rephrase references to "time qualification".

  32. Move remaining code from tqual.[ch] to heapam.h / heapam_visibility.c.

  33. Move generic snapshot related code from tqual.h to snapmgr.h.

  34. Remove superfluous tqual.h includes.

  35. Don't duplicate parallel seqscan shmem sizing logic in nbtree.

  36. Move vacuumlazy.c into access/heap.

  37. Support parallel bitmap heap scans.