Horton

Re: Pluggable Storage - Andres's take

Beena Emerson <memissemerson@gmail.com>

View thread View on postgr.es
From: Beena Emerson <memissemerson@gmail.com>
To: Amit Kapila <amit.kapila16@gmail.com>
Cc: Haribabu Kommi <kommi.haribabu@gmail.com>, Mithun Cy <mithun.cy@enterprisedb.com>, Andres Freund <andres@anarazel.de>, Alvaro Herrera <alvherre@2ndquadrant.com>, Alexander Korotkov <a.korotkov@postgrespro.ru>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2018-09-11T08:00:46Z
Lists: pgsql-hackers 
Hello,

On Mon, 10 Sep 2018, 19:33 Amit Kapila, <amit.kapila16@gmail.com> wrote:

> On Mon, Sep 10, 2018 at 1:12 PM Haribabu Kommi <kommi.haribabu@gmail.com>
> wrote:
> >
> > On Wed, Sep 5, 2018 at 2:04 PM Haribabu Kommi <kommi.haribabu@gmail.com>
> wrote:
> >>
> > pg_stat_get_tuples_hot_updated and others:
> > /*
> > * Counter tuples_hot_updated stores number of hot updates for heap table
> > * and the number of inplace updates for zheap table.
> > */
> > if ((tabentry = pgstat_fetch_stat_tabentry(relid)) == NULL ||
> > RelationStorageIsZHeap(rel))
> > result = 0;
> > else
> > result = (int64) (tabentry->tuples_hot_updated);
> >
> >
> > Is the special condition is needed? The values should be 0 because of
> zheap right?
> >
>
> I also think so.  Beena/Mithun has worked on this part of the code, so
> it is better if they also confirm once.
>

We have used the hot_updated counter to count the number of inplace updates
for zheap to qvoid introducing a new counter. Though, technically, hot
updates are 0 for zheap, the counter could hold non-zero value indicating
the inplace updates.

Thank you

>

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.