Horton

Re: Pluggable Storage - Andres's take

Andres Freund <andres@anarazel.de>

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From: Andres Freund <andres@anarazel.de>
To: Dmitry Dolgov <9erthalion6@gmail.com>
Cc: Haribabu Kommi <kommi.haribabu@gmail.com>, Amit Langote <Langote_Amit_f8@lab.ntt.co.jp>, Peter Geoghegan <pg@bowt.ie>, Alvaro Herrera <alvherre@2ndquadrant.com>, Alexander Korotkov <a.korotkov@postgrespro.ru>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2019-01-12T00:44:40Z
Lists: pgsql-hackers 
Hi,

On 2019-01-12 01:35:06 +0100, Dmitry Dolgov wrote:
> > On Sat, Dec 15, 2018 at 8:37 PM Andres Freund <andres@anarazel.de> wrote:
> >
> > We need to dump the table access method at dump time, otherwise we loose
> > that information.
> 
> As a result of the discussion in [1] (btw, thanks for starting it), here is
> proposed solution with tracking current default_table_access_method. Next I'll
> tackle similar issue for psql and probably add some tests for both patches.

Thanks!

> +/*
> + * Set the proper default_table_access_method value for the table.
> + */
> +static void
> +_selectTableAccessMethod(ArchiveHandle *AH, const char *tableam)
> +{
> +	PQExpBuffer cmd = createPQExpBuffer();
> +	const char *want, *have;
> +
> +	have = AH->currTableAm;
> +	want = tableam;
> +
> +	if (!want)
> +		return;
> +
> +	if (have && strcmp(want, have) == 0)
> +		return;
> +
> +
> +	appendPQExpBuffer(cmd, "SET default_table_access_method = %s;", tableam);

This needs escaping, at the very least with "", but better with proper
routines for dealing with identifiers.



> @@ -5914,7 +5922,7 @@ getTables(Archive *fout, int *numTables)
>  						  "tc.relfrozenxid AS tfrozenxid, "
>  						  "tc.relminmxid AS tminmxid, "
>  						  "c.relpersistence, c.relispopulated, "
> -						  "c.relreplident, c.relpages, "
> +						  "c.relreplident, c.relpages, am.amname AS amname, "

That AS doesn't do anything, does it?


>  		/* other fields were zeroed above */
>  
> @@ -9355,7 +9370,7 @@ dumpComment(Archive *fout, const char *type, const char *name,
>  		 * post-data.
>  		 */
>  		ArchiveEntry(fout, nilCatalogId, createDumpId(),
> -					 tag->data, namespace, NULL, owner,
> +					 tag->data, namespace, NULL, owner, NULL,
>  					 "COMMENT", SECTION_NONE,
>  					 query->data, "", NULL,
>  					 &(dumpId), 1,

We really ought to move the arguments to a struct, so we don't generate
quite as much useless diffs whenever we do a change around one of
these...

Greetings,

Andres Freund

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.