Horton

Re: Pluggable Storage - Andres's take

Amit Khandekar <amitdkhan.pg@gmail.com>

View thread View on postgr.es
From: Amit Khandekar <amitdkhan.pg@gmail.com>
To: Dmitry Dolgov <9erthalion6@gmail.com>
Cc: Andres Freund <andres@anarazel.de>, 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: 2019-01-18T10:21:28Z
Lists: pgsql-hackers 
On Fri, 18 Jan 2019 at 10:13, Amit Khandekar <amitdkhan.pg@gmail.com> wrote:
> On Tue, 15 Jan 2019 at 17:58, Dmitry Dolgov <9erthalion6@gmail.com> wrote:

> > Also I guess another attached patch should address the psql part, namely
> > displaying a table access method with \d+ and possibility to hide it with a
> > psql variable (HIDE_TABLEAM, but I'm open for suggestion about the name).

I am ok with the name.

>
> Will have a look at this one.

--- a/src/test/regress/expected/copy2.out
+++ b/src/test/regress/expected/copy2.out
@@ -1,3 +1,4 @@
+\set HIDE_TABLEAM on
 CREATE TEMP TABLE x (

I thought we wanted to avoid having to add this setting in individual
regression tests. Can't we do this in pg_regress as a common setting ?

+ /* Access method info */
+ if (pset.sversion >= 120000 && verbose && tableinfo.relam != NULL &&
+    !(pset.hide_tableam && tableinfo.relam_is_default))
+ {
+         printfPQExpBuffer(&buf, _("Access method: %s"),
fmtId(tableinfo.relam));

So this will make psql hide the access method if it's same as the
default. I understand that this was kind of concluded in the other
thread "Displaying and dumping of table access methods". But IMHO, if
the hide_tableam is false, we should *always* show the access method,
regardless of the default value. I mean, we can make it simple : off
means never show table-access, on means always show table-access,
regardless of the default access method. And this also will work with
regression tests. If some regression test wants specifically to output
the access method, it can have a "\SET HIDE_TABLEAM off" command.

If we hide the method if it's default, then for a regression test that
wants to forcibly show the table access method of all tables, it won't
show up for tables that have default access method.

------------

+ if (pset.sversion >= 120000 && verbose && tableinfo.relam != NULL &&

If the server does not support relam, tableinfo.relam will be NULL
anyways. So I think sversion check is not needed.

------------

+ printfPQExpBuffer(&buf, _("Access method: %s"), fmtId(tableinfo.relam));
fmtId is not required. In fact, we should display the access method
name as-is. fmtId is required only for identifiers present in SQL
queries.

-----------

+      printfPQExpBuffer(&buf, _("Access method: %s"), fmtId(tableinfo.relam));
+      printTableAddFooter(&cont, buf.data);
+   }
+
+
 }

Last two blank lines are not needed.

-----------

+ bool            hide_tableam;
 } PsqlSettings;

These variables, it seems, are supposed to be grouped together by type.

-----------

I believe you are going to add a new regression testcase for the change ?


-- 
Thanks,
-Amit Khandekar
EnterpriseDB Corporation
The Postgres Database Company

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.