Horton

Re: Pluggable Storage - Andres's take

Haribabu Kommi <kommi.haribabu@gmail.com>

View thread View on postgr.es
From: Haribabu Kommi <kommi.haribabu@gmail.com>
To: Amit Langote <Langote_Amit_f8@lab.ntt.co.jp>
Cc: Dmitry Dolgov <9erthalion6@gmail.com>, Andres Freund <andres@anarazel.de>, Alvaro Herrera <alvherre@2ndquadrant.com>, Alexander Korotkov <a.korotkov@postgrespro.ru>, Pg Hackers <pgsql-hackers@postgresql.org>
Date: 2019-02-20T03:44:21Z
Lists: pgsql-hackers 
On Tue, Nov 27, 2018 at 4:59 PM Amit Langote <Langote_Amit_f8@lab.ntt.co.jp>
wrote:

> Hi,
>
> On 2018/11/02 9:17, Haribabu Kommi wrote:
> > Here I attached the cumulative fixes of the patches, new API additions
> for
> > zheap and
> > basic outline of the documentation.
>
> I've read the documentation patch while also looking at the code and here
> are some comments.
>

Thanks for the review and apologies for the delay.
I have taken care of your most of the comments in the latest version of the
doc patches.


>
> +  <para>
> +<programlisting>
> +TupleTableSlotOps *
> +slot_callbacks (Relation relation);
> +</programlisting>
> +   API to access the slot specific methods;
> +   Following methods are available;
> +   <structname>TTSOpsVirtual</structname>,
> +   <structname>TTSOpsHeapTuple</structname>,
> +   <structname>TTSOpsMinimalTuple</structname>,
> +   <structname>TTSOpsBufferTuple</structname>,
> +  </para>
>
> Unless I'm misunderstanding what the TupleTableSlotOps abstraction is or
> its relations to the TableAmRoutine abstraction, I think the text
> description could better be written as:
>
> "API to get the slot operations struct for a given table access method"
>
> It's not clear to me why various TTSOps* structs are listed here?  Is the
> point that different AMs may choose one of the listed alternatives?  For
> example, I see that heap AM implementation returns TTOpsBufferTuple, so it
> manipulates slots containing buffered tuples, right?  Other AMs are free
> to return any one of these?  For example, some AMs may never use buffer
> manager and hence not use TTOpsBufferTuple.  Is that understanding correct?
>

Yes, AM can decide what type of Slot method it wants to use.

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.