Horton

Re: Pluggable Storage - Andres's take

Ashwin Agrawal <aagrawal@pivotal.io>

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From: Ashwin Agrawal <aagrawal@pivotal.io>
To: Andres Freund <andres@anarazel.de>
Cc: Heikki Linnakangas <hlinnaka@iki.fi>, Haribabu Kommi <kommi.haribabu@gmail.com>, Asim R P <apraveen@pivotal.io>, Pg Hackers <pgsql-hackers@postgresql.org>, Dmitry Dolgov <9erthalion6@gmail.com>, Alvaro Herrera <alvherre@2ndquadrant.com>, Alexander Korotkov <a.korotkov@postgrespro.ru>
Date: 2019-03-06T02:27:45Z
Lists: pgsql-hackers 
Hi,

While playing with the tableam, usage of which starts with commit
v12-0023-tableam-Introduce-and-use-begin-endscan-and-do-i.patch, should we
check for NULL function pointer before actually calling the same and ERROR
out instead as NOT_SUPPORTED or something on those lines.

Understand its kind of think which should get caught during development.
But still currently it segfaults if missing to define some AM function,
might be easier for iterative development to error instead in common place.

Or should there be upfront check for NULL somewhere if all the AM functions
are mandatory to have functions defined for them and should not be NULL.

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.