It's now possible to specify a table access method via
CREATE TABLE ... USING for a partitioned table, as well change it with
ALTER TABLE ... SET ACCESS METHOD. Specifying an AM for a partitioned
table lets the value be used for all future partitions created under it,
closely mirroring the behavior of the TABLESPACE option for partitioned
tables. Existing partitions are not modified.
For a partitioned table with no AM specified, any new partitions are
created with the default_table_access_method.
Also add ALTER TABLE ... SET ACCESS METHOD DEFAULT, which reverts to the
original state of using the default for new partitions.
The relcache of partitioned tables is not changed: rd_tableam is not
set, even if a partitioned table has a relam set.
Author: Justin Pryzby <pryzby@telsasoft.com>
Author: Soumyadeep Chakraborty <soumyadeep2007@gmail.com>
Author: Michaël Paquier <michael@paquier.xyz>
Reviewed-by: The authors themselves
Discussion: https://postgr.es/m/CAE-ML+9zM4wJCGCBGv01k96qQ3gFv4WFcFy=zqPHKeaEFwwv6A@mail.gmail.com
Discussion: https://postgr.es/m/20210308010707.GA29832%40telsasoft.com
This option can be used to switch a relation to use the access method
set by default_table_access_method when running the command.
This has come up when discussing the possibility to support setting
pg_class.relam for partitioned tables (left out here as future work),
while being useful on its own for relations with physical storage as
these must have an access method set.
Per suggestion from Justin Pryzby.
Author: Michael Paquier
Reviewed-by: Justin Pryzby
Discussion: https://postgr.es/m/ZeCZ89xAVFeOmrQC@pryzbyj2023
ALTER TABLE .. SET ACCESS METHOD was not registering a dependency to the
new access method with the relation altered in its rewrite phase, making
possible the drop of an access method even if there are relations that
depend on it. During the rewrite, a temporary relation is created to
build the new relation files before swapping the new and old files, and,
while the temporary relation was registering a correct dependency to the
new AM, the old relation did not do that. A dependency on the access
method is added when the relation files are swapped, which is the point
where pg_class is updated.
Materialized views and tables use the same code path, hence both were
impacted.
Backpatch down to 15, where this command has been introduced.
Reported-by: Alexander Lakhin
Reviewed-by: Nathan Bossart, Andres Freund
Discussion: https://postgr.es/m/18000-9145c25b1af475ca@postgresql.org
Backpatch-through: 15
b048326 has added support for SET ACCESS METHOD in ALTER TABLE, but it
has missed a few things for materialized views:
- No documentation for this clause on the ALTER MATERIALIZED VIEW page.
- psql tab completion missing.
- No regression tests.
This commit closes the gap on all the points listed above.
Author: Yugo Nagata
Discussion: https://postgr.es/m/20220316133337.5dc9740abfa24c25ec9f67f5@sraoss.co.jp
The logic used to support a change of access method for a table is
similar to changes for tablespace or relation persistence, requiring a
table rewrite with an exclusive lock of the relation changed. Table
rewrites done in ALTER TABLE already go through the table AM layer when
scanning tuples from the old relation and inserting them into the new
one, making this implementation straight-forward.
Note that partitioned tables are not supported as these have no access
methods defined.
Author: Justin Pryzby, Jeff Davis
Reviewed-by: Michael Paquier, Vignesh C
Discussion: https://postgr.es/m/20210228222530.GD20769@telsasoft.com
Remove old containment operators @ and ~ for built-in geometry data
types. These have been deprecated; use <@ and @> instead.
(Some contrib modules still contain the same deprecated operators.
That will be dealt with separately.)
Author: Justin Pryzby <pryzby@telsasoft.com>
Discussion: https://www.postgresql.org/message-id/flat/20201027032511.GF9241@telsasoft.com
The "DROP ACCESS METHOD gist2" test will require locking the index
to be dropped and then its table; while most ordinary operations
lock a table first then its index. While no concurrent test scripts
should be touching fast_emp4000, autovacuum might chance to be
processing that table when the DROP runs, resulting in a deadlock
failure. This is pretty rare but we see it in the buildfarm from
time to time.
To fix, acquire a lock on fast_emp4000 before issuing the DROP.
Since the point of the exercise is mostly to prevent buildfarm
failures, back-patch to 9.6 where this test was introduced.
Discussion: https://postgr.es/m/839004.1599185607@sss.pgh.pa.us
Previously it was allowed to set default_table_access_method to an
empty string. That makes sense for default_tablespace, where that was
copied from, as it signals falling back to the database's default
tablespace. As there is no equivalent for table AMs, forbid that.
Also make sure to throw a usable error when creating a table using an
index AM, by using get_am_type_oid() to implement get_table_am_oid()
instead of a separate copy. Previously we'd error out only later, in
GetTableAmRoutine().
Thirdly remove GetTableAmRoutineByAmId() - it was only used in an
earlier version of 8586bf7ed8.
Add tests for the above (some for index AMs as well).
This introduces the concept of table access methods, i.e. CREATE
ACCESS METHOD ... TYPE TABLE and
CREATE TABLE ... USING (storage-engine).
No table access functionality is delegated to table AMs as of this
commit, that'll be done in following commits.
Subsequent commits will incrementally abstract table access
functionality to be routed through table access methods. That change
is too large to be reviewed & committed at once, so it'll be done
incrementally.
Docs will be updated at the end, as adding them incrementally would
likely make them less coherent, and definitely is a lot more work,
without a lot of benefit.
Table access methods are specified similar to index access methods,
i.e. pg_am.amhandler returns, as INTERNAL, a pointer to a struct with
callbacks. In contrast to index AMs that struct needs to live as long
as a backend, typically that's achieved by just returning a pointer to
a constant struct.
Psql's \d+ now displays a table's access method. That can be disabled
with HIDE_TABLEAM=true, which is mainly useful so regression tests can
be run against different AMs. It's quite possible that this behaviour
still needs to be fine tuned.
For now it's not allowed to set a table AM for a partitioned table, as
we've not resolved how partitions would inherit that. Disallowing
allows us to introduce, if we decide that's the way forward, such a
behaviour without a compatibility break.
Catversion bumped, to add the heap table AM and references to it.
Author: Haribabu Kommi, Andres Freund, Alvaro Herrera, Dimitri Golgov and others
Discussion:
https://postgr.es/m/20180703070645.wchpu5muyto5n647@alap3.anarazel.dehttps://postgr.es/m/20160812231527.GA690404@alvherre.pgsqlhttps://postgr.es/m/20190107235616.6lur25ph22u5u5av@alap3.anarazel.dehttps://postgr.es/m/20190304234700.w5tmhducs5wxgzls@alap3.anarazel.de
The preceding patch allowed us to remove useless GiST support functions.
This patch actually does that for all the no-op cases in the core GiST
code. This buys us whatever performance gain is to be had, and more
importantly exercises the preceding patch.
There remain no-op functions in the contrib GiST opclasses, but those
will take more work to remove.
Discussion: https://postgr.es/m/CAJEAwVELVx9gYscpE=Be6iJxvdW5unZ_LkcAaVNSeOwvdwtD=A@mail.gmail.com
For a long time, opclasscmds.c explained that "we do not create a
dependency link to the AM [for an opclass or opfamily], because we don't
currently support DROP ACCESS METHOD". Commit 473b932870 invented
DROP ACCESS METHOD, but it batted only 1 for 2 on adding the dependency
links, and 0 for 2 on updating the comments about the topic.
In passing, undo the same commit's entirely inappropriate decision to
blow away an existing index as a side-effect of create_am.sql.
This enables external code to create access methods. This is useful so
that extensions can add their own access methods which can be formally
tracked for dependencies, so that DROP operates correctly. Also, having
explicit support makes pg_dump work correctly.
Currently only index AMs are supported, but we expect different types to
be added in the future.
Authors: Alexander Korotkov, Petr Jelínek
Reviewed-By: Teodor Sigaev, Petr Jelínek, Jim Nasby
Commitfest-URL: https://commitfest.postgresql.org/9/353/
Discussion: https://www.postgresql.org/message-id/CAPpHfdsXwZmojm6Dx+TJnpYk27kT4o7Ri6X_4OSWcByu1Rm+VA@mail.gmail.com
Alvaro Herrera
Michael Paquier
Peter Eisentraut
Tom Lane
Noah Misch
Andres Freund