Commit 8ff1c94649 extended TRUNCATE command so that it can also truncate
foreign tables. But it forgot to support tab-complete for TRUNCATE on
foreign tables. That is, previously tab-complete for TRUNCATE displayed
only the names of regular tables.
This commit improves tab-complete for TRUNCATE so that it displays also
the names of foreign tables.
Author: Fujii Masao
Reviewed-by: Bharath Rupireddy
Discussion: https://postgr.es/m/551ed8c1-f531-818b-664a-2cecdab99cd8@oss.nttdata.com
Documentation and comments in code and tests have been using the terms
sensitive/insensitive cursor incorrectly relative to the SQL standard.
(Cursor sensitivity is only relevant for changes made in the same
transaction as the cursor, not for concurrent changes in other
sessions.) Moreover, some of the behavior of PostgreSQL is incorrect
according to the SQL standard, confusing the issue further. (WHERE
CURRENT OF changes are not visible in insensitive cursors, but they
should be.)
This change corrects the terminology and removes the claim that
sensitive cursors are supported. It also adds a test case that checks
the insensitive behavior in a "correct" way, using a change command
not using WHERE CURRENT OF. Finally, it adds the ASENSITIVE cursor
option to select the default asensitive behavior, per SQL standard.
There are no changes to cursor behavior in this patch.
Discussion: https://www.postgresql.org/message-id/flat/96ee8b30-9889-9e1b-b053-90e10c050e85%40enterprisedb.com
Previously, psql printed only the last result if a command string
returned multiple result sets. Now it prints all of them. The
previous behavior can be obtained by setting the psql variable
SHOW_ALL_RESULTS to off.
Author: Fabien COELHO <coelho@cri.ensmp.fr>
Reviewed-by: "Iwata, Aya" <iwata.aya@jp.fujitsu.com>
Reviewed-by: Daniel Verite <daniel@manitou-mail.org>
Reviewed-by: Peter Eisentraut <peter.eisentraut@2ndquadrant.com>
Reviewed-by: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Reviewed-by: vignesh C <vignesh21@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/alpine.DEB.2.21.1904132231510.8961@lancre
At present, if we want to update publications in a subscription, we
can use SET PUBLICATION. However, it requires supplying all
publications that exists and the new publications. If we want to add
new publications, it's inconvenient. The new syntax only supplies the
new publications. When the refresh is true, it only refreshes the new
publications.
Author: Japin Li <japinli@hotmail.com>
Author: Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/MEYP282MB166939D0D6C480B7FBE7EFFBB6BC0@MEYP282MB1669.AUSP282.PROD.OUTLOOK.COM
To allow inserts in parallel-mode this feature has to ensure that all the
constraints, triggers, etc. are parallel-safe for the partition hierarchy
which is costly and we need to find a better way to do that. Additionally,
we could have used existing cached information in some cases like indexes,
domains, etc. to determine the parallel-safety.
List of commits reverted, in reverse chronological order:
ed62d3737c Doc: Update description for parallel insert reloption.
c8f78b6161 Add a new GUC and a reloption to enable inserts in parallel-mode.
c5be48f092 Improve FK trigger parallel-safety check added by 05c8482f7f.
e2cda3c20a Fix use of relcache TriggerDesc field introduced by commit 05c8482f7f.
e4e87a32cc Fix valgrind issue in commit 05c8482f7f.
05c8482f7f Enable parallel SELECT for "INSERT INTO ... SELECT ...".
Discussion: https://postgr.es/m/E1lMiB9-0001c3-SY@gemulon.postgresql.org
There is now a per-column COMPRESSION option which can be set to pglz
(the default, and the only option in up until now) or lz4. Or, if you
like, you can set the new default_toast_compression GUC to lz4, and
then that will be the default for new table columns for which no value
is specified. We don't have lz4 support in the PostgreSQL code, so
to use lz4 compression, PostgreSQL must be built --with-lz4.
In general, TOAST compression means compression of individual column
values, not the whole tuple, and those values can either be compressed
inline within the tuple or compressed and then stored externally in
the TOAST table, so those properties also apply to this feature.
Prior to this commit, a TOAST pointer has two unused bits as part of
the va_extsize field, and a compessed datum has two unused bits as
part of the va_rawsize field. These bits are unused because the length
of a varlena is limited to 1GB; we now use them to indicate the
compression type that was used. This means we only have bit space for
2 more built-in compresison types, but we could work around that
problem, if necessary, by introducing a new vartag_external value for
any further types we end up wanting to add. Hopefully, it won't be
too important to offer a wide selection of algorithms here, since
each one we add not only takes more coding but also adds a build
dependency for every packager. Nevertheless, it seems worth doing
at least this much, because LZ4 gets better compression than PGLZ
with less CPU usage.
It's possible for LZ4-compressed datums to leak into composite type
values stored on disk, just as it is for PGLZ. It's also possible for
LZ4-compressed attributes to be copied into a different table via SQL
commands such as CREATE TABLE AS or INSERT .. SELECT. It would be
expensive to force such values to be decompressed, so PostgreSQL has
never done so. For the same reasons, we also don't force recompression
of already-compressed values even if the target table prefers a
different compression method than was used for the source data. These
architectural decisions are perhaps arguable but revisiting them is
well beyond the scope of what seemed possible to do as part of this
project. However, it's relatively cheap to recompress as part of
VACUUM FULL or CLUSTER, so this commit adjusts those commands to do
so, if the configured compression method of the table happens not to
match what was used for some column value stored therein.
Dilip Kumar. The original patches on which this work was based were
written by Ildus Kurbangaliev, and those were patches were based on
even earlier work by Nikita Glukhov, but the design has since changed
very substantially, since allow a potentially large number of
compression methods that could be added and dropped on a running
system proved too problematic given some of the architectural issues
mentioned above; the choice of which specific compression method to
add first is now different; and a lot of the code has been heavily
refactored. More recently, Justin Przyby helped quite a bit with
testing and reviewing and this version also includes some code
contributions from him. Other design input and review from Tomas
Vondra, Álvaro Herrera, Andres Freund, Oleg Bartunov, Alexander
Korotkov, and me.
Discussion: http://postgr.es/m/20170907194236.4cefce96%40wp.localdomain
Discussion: http://postgr.es/m/CAFiTN-uUpX3ck%3DK0mLEk-G_kUQY%3DSNOTeqdaNRR9FMdQrHKebw%40mail.gmail.com
Only "IMPORT" was showing as result of the completion, while IMPORT
FOREIGN SCHEMA is the only command using this keyword in first
position. This changes the completion to show the full command name
instead of just "IMPORT".
Reviewed-by: Georgios Kokolatos, Julien Rouhaud
Discussion: https://postgr.es/m/YFL6JneBiuMWYyoh@paquier.xyz
Commit 05c8482f7f added the implementation of parallel SELECT for
"INSERT INTO ... SELECT ..." which may incur non-negligible overhead in
the additional parallel-safety checks that it performs, even when, in the
end, those checks determine that parallelism can't be used. This is
normally only ever a problem in the case of when the target table has a
large number of partitions.
A new GUC option "enable_parallel_insert" is added, to allow insert in
parallel-mode. The default is on.
In addition to the GUC option, the user may want a mechanism to allow
inserts in parallel-mode with finer granularity at table level. The new
table option "parallel_insert_enabled" allows this. The default is true.
Author: "Hou, Zhijie"
Reviewed-by: Greg Nancarrow, Amit Langote, Takayuki Tsunakawa, Amit Kapila
Discussion: https://postgr.es/m/CAA4eK1K-cW7svLC2D7DHoGHxdAdg3P37BLgebqBOC2ZLc9a6QQ%40mail.gmail.com
Discussion: https://postgr.es/m/CAJcOf-cXnB5cnMKqWEp2E2z7Mvcd04iLVmV=qpFJrR3AcrTS3g@mail.gmail.com
Remove the entire idea of "stale stats" within nbtree VACUUM (stop
caring about stats involving the number of inserted tuples). Also
remove the vacuum_cleanup_index_scale_factor GUC/param on the master
branch (though just disable them on postgres 13).
The vacuum_cleanup_index_scale_factor/stats interface made the nbtree AM
partially responsible for deciding when pg_class.reltuples stats needed
to be updated. This seems contrary to the spirit of the index AM API,
though -- it is not actually necessary for an index AM's bulk delete and
cleanup callbacks to provide accurate stats when it happens to be
inconvenient. The core code owns that. (Index AMs have the authority
to perform or not perform certain kinds of deferred cleanup based on
their own considerations, such as page deletion and recycling, but that
has little to do with pg_class.reltuples/num_index_tuples.)
This issue was fairly harmless until the introduction of the
autovacuum_vacuum_insert_threshold feature by commit b07642db, which had
an undesirable interaction with the vacuum_cleanup_index_scale_factor
mechanism: it made insert-driven autovacuums perform full index scans,
even though there is no real benefit to doing so. This has been tied to
a regression with an append-only insert benchmark [1].
Also have remaining cases that perform a full scan of an index during a
cleanup-only nbtree VACUUM indicate that the final tuple count is only
an estimate. This prevents vacuumlazy.c from setting the index's
pg_class.reltuples in those cases (it will now only update pg_class when
vacuumlazy.c had TIDs for nbtree to bulk delete). This arguably fixes
an oversight in deduplication-related bugfix commit 48e12913.
[1] https://smalldatum.blogspot.com/2021/01/insert-benchmark-postgres-is-still.html
Author: Peter Geoghegan <pg@bowt.ie>
Reviewed-By: Masahiko Sawada <sawada.mshk@gmail.com>
Discussion: https://postgr.es/m/CAD21AoA4WHthN5uU6+WScZ7+J_RcEjmcuH94qcoUPuB42ShXzg@mail.gmail.com
Backpatch: 13-, where autovacuum_vacuum_insert_threshold was added.
ALTER INDEX was able to handle that already. This adds tab completion
for all the remaining commands that support this grammar:
- ALTER FUNCTION
- ALTER PROCEDURE
- ALTER ROUTINE
- ALTER TRIGGER
- ALTER MATERIALIZED VIEW
Author: Ian Lawrence Barwick
Discussion: https://postgr.es/m/CAB8KJ=iypYudXuMOAMOP4BpkaYbXxk=a2cdJppX0e9mJXWtuig@mail.gmail.com
This option controls if toast tables associated with a relation are
vacuumed or not when running a manual VACUUM. It was already possible
to trigger a manual VACUUM on a toast relation without processing its
main relation, but a manual vacuum on a main relation always forced a
vacuum on its toast table. This is useful in scenarios where the level
of bloat or transaction age of the main and toast relations differs a
lot.
This option is an extension of the existing VACOPT_SKIPTOAST that was
used by autovacuum to control if toast relations should be skipped or
not. This internal flag is renamed to VACOPT_PROCESS_TOAST for
consistency with the new option.
A new option switch, called --no-process-toast, is added to vacuumdb.
Author: Nathan Bossart
Reviewed-by: Kirk Jamison, Michael Paquier, Justin Pryzby
Discussion: https://postgr.es/m/BA8951E9-1524-48C5-94AF-73B1F0D7857F@amazon.com
This patch adds the possibility to move indexes to a new tablespace
while rebuilding them. Both the concurrent and the non-concurrent cases
are supported, and the following set of restrictions apply:
- When using TABLESPACE with a REINDEX command that targets a
partitioned table or index, all the indexes of the leaf partitions are
moved to the new tablespace. The tablespace references of the non-leaf,
partitioned tables in pg_class.reltablespace are not changed. This
requires an extra ALTER TABLE SET TABLESPACE.
- Any index on a toast table rebuilt as part of a parent table is kept
in its original tablespace.
- The operation is forbidden on system catalogs, including trying to
directly move a toast relation with REINDEX. This results in an error
if doing REINDEX on a single object. REINDEX SCHEMA, DATABASE and
SYSTEM skip system relations when TABLESPACE is used.
Author: Alexey Kondratov, Michael Paquier, Justin Pryzby
Reviewed-by: Álvaro Herrera, Michael Paquier
Discussion: https://postgr.es/m/8a8f5f73-00d3-55f8-7583-1375ca8f6a91@postgrespro.ru
The new command lists extended statistics objects. All past releases
with extended statistics are supported.
This is a simplified version of commit 891a1d0bca, which had to be
reverted due to not considering pg_statistic_ext_data is not accessible
by regular users. Fields requiring access to this catalog were removed.
It's possible to add them, but it'll require changes to core.
Author: Tatsuro Yamada
Reviewed-by: Julien Rouhaud, Alvaro Herrera, Tomas Vondra, Noriyoshi Shinoda
Discussion: https://postgr.es/m/c027a541-5856-75a5-0868-341301e1624b%40nttcom.co.jp_1
The new command lists extended statistics objects, possibly with their
sizes. All past releases with extended statistics are supported.
Author: Tatsuro Yamada
Reviewed-by: Julien Rouhaud, Alvaro Herrera, Tomas Vondra
Discussion: https://postgr.es/m/c027a541-5856-75a5-0868-341301e1624b%40nttcom.co.jp_1
This commit makes CLOSE, FETCH and MOVE commands tab-complete the list of
cursors. Also this commit makes DECLARE command tab-complete the options.
Author: Shinya Kato, Sawada Masahiko, tweaked by Fujii Masao
Reviewed-by: Shinya Kato, Sawada Masahiko, Fujii Masao
Discussion: https://postgr.es/m/b0e4c5c53ef84c5395524f5056fc71f0@MP-MSGSS-MBX001.msg.nttdata.co.jp
This changes CLUSTER and REINDEX so as a parenthesized grammar becomes
possible for options, while unifying the grammar parsing rules for
option lists with the existing ones.
This is a follow-up of the work done in 873ea9e for VACUUM, ANALYZE and
EXPLAIN. This benefits REINDEX for a potential backend-side filtering
for collatable-sensitive indexes and TABLESPACE, while CLUSTER would
benefit from the latter.
Author: Alexey Kondratov, Justin Pryzby
Discussion: https://postgr.es/m/8a8f5f73-00d3-55f8-7583-1375ca8f6a91@postgrespro.ru
Record the current version of dependent collations in pg_depend when
creating or rebuilding an index. When accessing the index later, warn
that the index may be corrupted if the current version doesn't match.
Thanks to Douglas Doole, Peter Eisentraut, Christoph Berg, Laurenz Albe,
Michael Paquier, Robert Haas, Tom Lane and others for very helpful
discussion.
Author: Thomas Munro <thomas.munro@gmail.com>
Author: Julien Rouhaud <rjuju123@gmail.com>
Reviewed-by: Peter Eisentraut <peter.eisentraut@2ndquadrant.com> (earlier versions)
Discussion: https://postgr.es/m/CAEepm%3D0uEQCpfq_%2BLYFBdArCe4Ot98t1aR4eYiYTe%3DyavQygiQ%40mail.gmail.com
It is not possible to get a list of foreign schemas as the server is not
known, so this provides instead a list of local schemas, which is more
useful than nothing if using a loopback server or having schema names
matching in the local and remote servers.
Author: Jeff Janes
Reviewed-by: Tom Lane, Michael Paquier
Discussion: https://postgr.es/m/CAMkU=1wr7Roj41q-XiJs=Uyc2xCmHhcGGy7J-peJQK-e+w=ghw@mail.gmail.com
This allows the tab completion of REINDEX to handle an optional
parenthesized list of options. This case is more complicated than
VACUUM or ANALYZE because of CONCURRENTLY and the different object types
to consider with the reindex.
Author: Justin Pryzby
Reviewed-by: Alexey Kondratov, Michael Paquier
Discussion: https://postgr.es/m/20200403182712.GR14618@telsasoft.com
The relkinds that support indexing are the same as the ones supporting
VACUUM, so the code gets refactored a bit with the completion query used
for CLUSTER, but there is no change for CLUSTER in this commit.
Author: Justin Pryzby
Reviewed-by: Fujii Masao, Michael Paquier, Masahiko Sawada
Discussion: https://postgr.es/m/20200728170408.GI20393@telsasoft.com
This corrects and simplifies $subject in a number of ways:
- Remove from the completion the pre-9.0 grammar still supported for
compatibility purposes. This simplifies the code, and allows to extend
it more easily with new patterns.
- Add completion for the options of FORMAT within a WITH clause.
- Complete WHERE and WITH clauses correctly depending on if TO or FROM
are used, WHERE being only available with COPY FROM.
Author: Vignesh C, Michael Paquier
Reviewed-by: Ahsan Hadi
Discussion: https://postgr.es/m/CALDaNm3zWr=OmxeNqOqfT=uZTSdam_j-gkX94CL8eTNfgUtf6A@mail.gmail.com
Thomas Munro fixed a longstanding annoyance in pg_bsd_indent, that
it would misformat lines containing IsA() macros on the assumption
that the IsA() call should be treated like a cast. This improves
some other cases involving field/variable names that match typedefs,
too. The only places that get worse are a couple of uses of the
OpenSSL macro STACK_OF(); we'll gladly take that trade-off.
Discussion: https://postgr.es/m/20200114221814.GA19630@alvherre.pgsql
Includes some manual cleanup of places that pgindent messed up,
most of which weren't per project style anyway.
Notably, it seems some people didn't absorb the style rules of
commit c9d297751, because there were a bunch of new occurrences
of function calls with a newline just after the left paren, all
with faulty expectations about how the rest of the call would get
indented.
... as added in the prior commit.
(We'd like to have tab-completion for the other object types too, but
they don't have sub-command completion yet.)
Author: Ibrar Ahmed <ibrar.ahmad@gmail.com>
Reviewed-by: Álvaro Herrera <alvherre@alvh.no-ip.org>
Discussion: https://postgr.es/m/CALtqXTcogrFEVP9uou5vFtnGsn+vHZUu9+9a0inarfYVOHScYQ@mail.gmail.com
This commit adds a new option WAL similar to existing option BUFFERS in the
EXPLAIN command. This option allows to include information on WAL record
generation added by commit df3b181499 in EXPLAIN output.
This also allows the WAL usage information to be displayed via
the auto_explain module. A new parameter auto_explain.log_wal controls
whether WAL usage statistics are printed when an execution plan is logged.
This parameter has no effect unless auto_explain.log_analyze is enabled.
Author: Julien Rouhaud
Reviewed-by: Dilip Kumar and Amit Kapila
Discussion: https://postgr.es/m/CAB-hujrP8ZfUkvL5OYETipQwA=e3n7oqHFU=4ZLxWS_Cza3kQQ@mail.gmail.com
Traditionally autovacuum has only ever invoked a worker based on the
estimated number of dead tuples in a table and for anti-wraparound
purposes. For the latter, with certain classes of tables such as
insert-only tables, anti-wraparound vacuums could be the first vacuum that
the table ever receives. This could often lead to autovacuum workers being
busy for extended periods of time due to having to potentially freeze
every page in the table. This could be particularly bad for very large
tables. New clusters, or recently pg_restored clusters could suffer even
more as many large tables may have the same relfrozenxid, which could
result in large numbers of tables requiring an anti-wraparound vacuum all
at once.
Here we aim to reduce the work required by anti-wraparound and aggressive
vacuums in general, by triggering autovacuum when the table has received
enough INSERTs. This is controlled by adding two new GUCs and reloptions;
autovacuum_vacuum_insert_threshold and
autovacuum_vacuum_insert_scale_factor. These work exactly the same as the
existing scale factor and threshold controls, only base themselves off the
number of inserts since the last vacuum, rather than the number of dead
tuples. New controls were added rather than reusing the existing
controls, to allow these new vacuums to be tuned independently and perhaps
even completely disabled altogether, which can be done by setting
autovacuum_vacuum_insert_threshold to -1.
We make no attempt to skip index cleanup operations on these vacuums as
they may trigger for an insert-mostly table which continually doesn't have
enough dead tuples to trigger an autovacuum for the purpose of removing
those dead tuples. If we were to skip cleaning the indexes in this case,
then it is possible for the index(es) to become bloated over time.
There are additional benefits to triggering autovacuums based on inserts,
as tables which never contain enough dead tuples to trigger an autovacuum
are now more likely to receive a vacuum, which can mark more of the table
as "allvisible" and encourage the query planner to make use of Index Only
Scans.
Currently, we still obey vacuum_freeze_min_age when triggering these new
autovacuums based on INSERTs. For large insert-only tables, it may be
beneficial to lower the table's autovacuum_freeze_min_age so that tuples
are eligible to be frozen sooner. Here we've opted not to zero that for
these types of vacuums, since the table may just be insert-mostly and we
may otherwise freeze tuples that are still destined to be updated or
removed in the near future.
There was some debate to what exactly the new scale factor and threshold
should default to. For now, these are set to 0.2 and 1000, respectively.
There may be some motivation to adjust these before the release.
Author: Laurenz Albe, Darafei Praliaskouski
Reviewed-by: Alvaro Herrera, Masahiko Sawada, Chris Travers, Andres Freund, Justin Pryzby
Discussion: https://postgr.es/m/CAC8Q8t%2Bj36G_bLF%3D%2B0iMo6jGNWnLnWb1tujXuJr-%2Bx8ZCCTqoQ%40mail.gmail.com
Introduce a GUC and a tablespace option to control I/O prefetching, much
like effective_io_concurrency, but for work that is done on behalf of
many client sessions.
Use the new setting in heapam.c instead of the hard-coded formula
effective_io_concurrency + 10 introduced by commit 558a9165e0. Go with
a default value of 10 for now, because it's a round number pretty close
to the value used for that existing case.
Discussion: https://postgr.es/m/CA%2BhUKGJUw08dPs_3EUcdO6M90GnjofPYrWp4YSLaBkgYwS-AqA%40mail.gmail.com
This commit provides psql commands for listing operator classes, operator
families and its contents in psql. New commands will be useful for exploring
capabilities of both builtin opclasses/opfamilies as well as
opclasses/opfamilies defined in extensions.
Discussion: https://postgr.es/m/1529675324.14193.5.camel%40postgrespro.ru
Author: Sergey Cherkashin, Nikita Glukhov, Alexander Korotkov
Reviewed-by: Michael Paquier, Alvaro Herrera, Arthur Zakirov
Reviewed-by: Kyotaro Horiguchi, Andres Freund
Specifically, this patch allows ALTER TYPE to:
* Change the default TOAST strategy for a toastable base type;
* Promote a non-toastable type to toastable;
* Add/remove binary I/O functions for a type;
* Add/remove typmod I/O functions for a type;
* Add/remove a custom ANALYZE statistics functions for a type.
The first of these can be done by the type's owner; all the others
require superuser privilege since misuse could cause problems.
The main motivation for this patch is to allow extensions to
upgrade the feature sets of their data types, so the set of
alterable properties is biased towards that use-case. However
it's also true that changing some other properties would be
a lot harder, as they get baked into physical storage and/or
stored expressions that depend on the type.
Along the way, refactor GenerateTypeDependencies() to make it easier
to call, refactor DefineType's volatility checks so they can be shared
by AlterType, and teach typcache.c that it might have to reload data
from the type's pg_type row, a scenario it never handled before.
Also rearrange alter_type.sgml a bit for clarity (put the
composite-type operations together).
Tomas Vondra and Tom Lane
Discussion: https://postgr.es/m/20200228004440.b23ein4qvmxnlpht@development
Deduplication reduces the storage overhead of duplicates in indexes that
use the standard nbtree index access method. The deduplication process
is applied lazily, after the point where opportunistic deletion of
LP_DEAD-marked index tuples occurs. Deduplication is only applied at
the point where a leaf page split would otherwise be required. New
posting list tuples are formed by merging together existing duplicate
tuples. The physical representation of the items on an nbtree leaf page
is made more space efficient by deduplication, but the logical contents
of the page are not changed. Even unique indexes make use of
deduplication as a way of controlling bloat from duplicates whose TIDs
point to different versions of the same logical table row.
The lazy approach taken by nbtree has significant advantages over a GIN
style eager approach. Most individual inserts of index tuples have
exactly the same overhead as before. The extra overhead of
deduplication is amortized across insertions, just like the overhead of
page splits. The key space of indexes works in the same way as it has
since commit dd299df8 (the commit that made heap TID a tiebreaker
column).
Testing has shown that nbtree deduplication can generally make indexes
with about 10 or 15 tuples for each distinct key value about 2.5X - 4X
smaller, even with single column integer indexes (e.g., an index on a
referencing column that accompanies a foreign key). The final size of
single column nbtree indexes comes close to the final size of a similar
contrib/btree_gin index, at least in cases where GIN's posting list
compression isn't very effective. This can significantly improve
transaction throughput, and significantly reduce the cost of vacuuming
indexes.
A new index storage parameter (deduplicate_items) controls the use of
deduplication. The default setting is 'on', so all new B-Tree indexes
automatically use deduplication where possible. This decision will be
reviewed at the end of the Postgres 13 beta period.
There is a regression of approximately 2% of transaction throughput with
synthetic workloads that consist of append-only inserts into a table
with several non-unique indexes, where all indexes have few or no
repeated values. The underlying issue is that cycles are wasted on
unsuccessful attempts at deduplicating items in non-unique indexes.
There doesn't seem to be a way around it short of disabling
deduplication entirely. Note that deduplication of items in unique
indexes is fairly well targeted in general, which avoids the problem
there (we can use a special heuristic to trigger deduplication passes in
unique indexes, since we're specifically targeting "version bloat").
Bump XLOG_PAGE_MAGIC because xl_btree_vacuum changed.
No bump in BTREE_VERSION, since the representation of posting list
tuples works in a way that's backwards compatible with version 4 indexes
(i.e. indexes built on PostgreSQL 12). However, users must still
REINDEX a pg_upgrade'd index to use deduplication, regardless of the
Postgres version they've upgraded from. This is the only way to set the
new nbtree metapage flag indicating that deduplication is generally
safe.
Author: Anastasia Lubennikova, Peter Geoghegan
Reviewed-By: Peter Geoghegan, Heikki Linnakangas
Discussion:
https://postgr.es/m/55E4051B.7020209@postgrespro.ruhttps://postgr.es/m/4ab6e2db-bcee-f4cf-0916-3a06e6ccbb55@postgrespro.ru
I had supposed that all versions of Readline that have filename
quoting hooks also have the rl_completion_suppress_quote variable.
But it seems OpenBSD managed to find a version someplace that does
not, so we'll have to expend a separate configure probe for that.
(Light testing suggests that this version also lacks the bugs that
make it necessary to frob that variable. Hooray!)
Per buildfarm.
The Readline library contains a fair amount of knowledge about how to
tab-complete filenames, but it turns out that that doesn't work too well
unless we follow its expectation that we use its filename quoting hooks
to quote and de-quote filenames. We were trying to do such quote handling
within complete_from_files(), and that's still what we have to do if we're
using libedit, which lacks those hooks. But for Readline, it works a lot
better if we tell Readline that single-quote is a quoting character and
then provide hooks that know the details of the quoting rules for SQL
and psql meta-commands.
Hence, resurrect the quoting hook functions that existed in the original
version of tab-complete.c (and were disabled by commit f6689a328 because
they "didn't work so well yet"), and whack on them until they do seem to
work well.
Notably, this fixes bug #16059 from Steven Winfield, who pointed out
that the previous coding would strip quote marks from filenames in SQL
COPY commands, even though they're syntactically necessary there.
Now, we not only don't do that, but we'll add a quote mark when you
tab-complete, even if you didn't type one.
Getting this to work across a range of libedit versions (and, to a
lesser extent, libreadline versions) was depressingly difficult.
It will be interesting to see whether the new regression test cases
pass everywhere in the buildfarm.
Some future patch might try to handle quoted SQL identifiers with
similar explicit quoting/dequoting logic, but that's for another day.
Patch by me, reviewed by Peter Eisentraut.
Discussion: https://postgr.es/m/16059-8836946734c02b84@postgresql.org
This feature allows the vacuum to leverage multiple CPUs in order to
process indexes. This enables us to perform index vacuuming and index
cleanup with background workers. This adds a PARALLEL option to VACUUM
command where the user can specify the number of workers that can be used
to perform the command which is limited by the number of indexes on a
table. Specifying zero as a number of workers will disable parallelism.
This option can't be used with the FULL option.
Each index is processed by at most one vacuum process. Therefore parallel
vacuum can be used when the table has at least two indexes.
The parallel degree is either specified by the user or determined based on
the number of indexes that the table has, and further limited by
max_parallel_maintenance_workers. The index can participate in parallel
vacuum iff it's size is greater than min_parallel_index_scan_size.
Author: Masahiko Sawada and Amit Kapila
Reviewed-by: Dilip Kumar, Amit Kapila, Robert Haas, Tomas Vondra,
Mahendra Singh and Sergei Kornilov
Tested-by: Mahendra Singh and Prabhat Sahu
Discussion:
https://postgr.es/m/CAD21AoDTPMgzSkV4E3SFo1CH_x50bf5PqZFQf4jmqjk-C03BWg@mail.gmail.comhttps://postgr.es/m/CAA4eK1J-VoR9gzS5E75pcD-OH0mEyCdp8RihcwKrcuw7J-Q0+w@mail.gmail.com
Debian unstable is shipping a broken version of libedit: it de-escapes
words before passing them to the application's tab completion function,
preventing us from recognizing backslash commands. Fortunately,
we have enough information available to dig the original text out of
rl_line_buffer, so ignore the string argument and do that.
I view this as a temporary workaround to get the affected buildfarm
members back to green in the wake of 7c015045b. I hope we can get
rid of it once somebody fixes Debian's libedit; hence, no back-patch,
at least for now.
Discussion: https://postgr.es/m/20200103110128.GA28967@msg.df7cb.de
Prefer to call "rl_filename_completion_function" and
"rl_completion_matches", rather than using the names without the rl_
prefix. This matches Readline's documentation, and makes our code
a little clearer about which names are external. On platforms that
only have the un-prefixed names (just some very ancient versions of
libedit, AFAICT), reverse the direction of the compatibility macro
definitions to match.
Also, remove our extern declaration of "filename_completion_function";
whatever libedit versions may have failed to declare that are surely
dead and buried.
Discussion: https://postgr.es/m/23608.1576248145@sss.pgh.pa.us
Fujii Masao
Tom Lane
Peter Eisentraut
Amit Kapila
Robert Haas
Michael Paquier
Peter Geoghegan
Thomas Munro
Tomas Vondra
Bruce Momjian
Alvaro Herrera
David Rowley
Alexander Korotkov