Several functions in the codebase accept "Datum *" parameters but do
not modify the pointed-to data. These have been updated to take
"const Datum *" instead, improving type safety and making the
interfaces clearer about their intent. This change helps the compiler
catch accidental modifications and better documents immutability of
arguments.
Most of "Datum *" parameters have a pairing "bool *isnull" parameter,
they are constified as well.
No functional behavior is changed by this patch.
Author: Chao Li <lic@highgo.com>
Discussion: https://www.postgresql.org/message-id/flat/CAEoWx2msfT0knvzUa72ZBwu9LR_RLY4on85w2a9YpE-o2By5HQ@mail.gmail.com
This new counter, called "wal_fpi_bytes", tracks the total amount in
bytes of full page images (FPIs) generated in WAL. This data becomes
available globally via pg_stat_wal, and for backend statistics via
pg_stat_get_backend_wal().
Previously, this information could only be retrieved with pg_waldump or
pg_walinspect, which may not be available depending on the environment,
and are expensive to execute. It offers hints about how much FPIs
impact the WAL generated, which could be a large percentage for some
workloads, as well as the effects of wal_compression or page holes.
Bump catalog version.
Bump PGSTAT_FILE_FORMAT_ID, due to the addition of wal_fpi_bytes in
PgStat_WalCounters.
Author: Shinya Kato <shinya11.kato@gmail.com>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/CAOzEurQtZEAfg6P0kU3Wa-f9BWQOi0RzJEMPN56wNTOmJLmfaQ@mail.gmail.com
This commit makes the way WAL segments are handled from the source to
the target server slightly smarter: the copy of the WAL segments is now
skipped if these have been created before the point where source and
target have diverged (the WAL segment where the point of divergence
exists is still copied), because we know that such segments exist on
both the target and source. Note that the on-disk size of the WAL
segments on the source and target need to match. Hence, only the
segments generated after the point of divergence are now copied. A
segment existing on the source but not the target is copied.
Previously, all the WAL segments were just copied in full. This change
can make the rewind operation cheaper in some configurations, especially
for setups where some WAL retention causes many segments to remain on
the source server even after the promotion of a standby used as source
to rewind a previous primary.
A TAP test is added to track these new behaviors. The file map printed
with --debug now includes all the information related to WAL segments,
to be able to track if these are copied or skipped, and the test relies
on the debug output generated.
Author: John Hsu <johnhyvr@gmail.com>
Author: Justin Kwan <justinpkwan@outlook.com>
Reviewed-by: Robert Haas <robertmhaas@gmail.com>
Reviewed-by: Alexander Korotkov <aekorotkov@gmail.com>
Reviewed-by: Japin Li <japinli@hotmail.com>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Reviewed-by: Srinath Reddy Sadipiralla <srinath2133@gmail.com>
Discussion: https://postgr.es/m/181b4c6fa9c.b8b725681941212.7547232617810891479@viggy28.dev
This patch adds support for a new SQL command:
ALTER SUBSCRIPTION ... REFRESH SEQUENCES
This command updates the sequence entries present in the
pg_subscription_rel catalog table with the INIT state to trigger
resynchronization.
In addition to the new command, the following subscription commands have
been enhanced to automatically refresh sequence mappings:
ALTER SUBSCRIPTION ... REFRESH PUBLICATION
ALTER SUBSCRIPTION ... ADD PUBLICATION
ALTER SUBSCRIPTION ... DROP PUBLICATION
ALTER SUBSCRIPTION ... SET PUBLICATION
These commands will perform the following actions:
Add newly published sequences that are not yet part of the subscription.
Remove sequences that are no longer included in the publication.
This ensures that sequence replication remains aligned with the current
state of the publication on the publisher side.
Note that the actual synchronization of sequence data/values will be
handled in a subsequent patch that introduces a dedicated sequence sync
worker.
Author: Vignesh C <vignesh21@gmail.com>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Reviewed-by: shveta malik <shveta.malik@gmail.com>
Reviewed-by: Masahiko Sawada <sawada.mshk@gmail.com>
Reviewed-by: Hayato Kuroda <kuroda.hayato@fujitsu.com>
Reviewed-by: Dilip Kumar <dilipbalaut@gmail.com>
Reviewed-by: Peter Smith <smithpb2250@gmail.com>
Reviewed-by: Nisha Moond <nisha.moond412@gmail.com>
Reviewed-by: Shlok Kyal <shlok.kyal.oss@gmail.com>
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Reviewed-by: Hou Zhijie <houzj.fnst@fujitsu.com>
Discussion: https://postgr.es/m/CAA4eK1LC+KJiAkSrpE_NwvNdidw9F2os7GERUeSxSKv71gXysQ@mail.gmail.com
Previously, attempting to use pg_checksums on a cluster with a control
file whose version does not match with what thetool is able to support
would lead to the following error:
pg_checksums: error: pg_control CRC value is incorrect
This is confusing, because it would look like the control file is
corrupted. However, the contents of the control file are correct,
pg_checksums not being able to understand how the past control file is
shaped.
This commit adds a check based on PG_VERSION, using the facility added
by cd0be131ba, using the same error message as some of the other
frontend tools. A note is added in the documentation about the major
version requirement.
Author: Michael Banck <mbanck@gmx.net>
Discussion: https://postgr.es/m/68f1ff21.170a0220.2c9b5f.4df5@mx.google.com
The log output functionality of log_autovacuum_min_duration applies to
both VACUUM and ANALYZE, so it is not possible to separate the VACUUM
and ANALYZE log output thresholds. Logs are likely to be output only for
VACUUM and not for ANALYZE.
Therefore, we decided to separate the threshold for log output of VACUUM
by autovacuum (log_autovacuum_min_duration) and the threshold for log
output of ANALYZE by autovacuum (log_autoanalyze_min_duration).
Author: Shinya Kato <shinya11.kato@gmail.com>
Reviewed-by: Kasahara Tatsuhito <kasaharatt@oss.nttdata.com>
Discussion: https://www.postgresql.org/message-id/flat/CAOzEurQtfV4MxJiWT-XDnimEeZAY+rgzVSLe8YsyEKhZcajzSA@mail.gmail.com
There was some confusion around how to adjust the n_distinct estimates
for partitioned tables. Here we try and clarify that
n_distinct_inherited needs to be adjusted rather than n_distinct.
Also fix some slightly misleading text which was talking about table
size rather than table rows, fix a grammatical error, and adjust some
text which indicated that ANALYZE was performing calculations based on
the n_distinct settings. Really it's the query planner that does this
and ANALYZE only stores the overridden n_distinct estimate value in
pg_statistic.
Author: David Rowley <dgrowleyml@gmail.com>
Reviewed-by: David G. Johnston <david.g.johnston@gmail.com>
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Backpatch-through: 13
Discussion: https://postgr.es/m/CAApHDvrL7a-ZytM1SP8Uk9nEw9bR2CPzVb+uP+bcNj=_q-ZmVw@mail.gmail.com
Since protocol version 3.2 the CancelRequest does not have a fixed size
length anymore. The protocol docs still listed the length field to be a
constant number though. This fixes that.
Author: Jelte Fennema-Nio <postgres@jeltef.nl>
Reported-by: Dmitry Igrishin <dmitigr@gmail.com>
Backpatch-through: 18
This patch adds support for the ALL SEQUENCES clause in publications,
enabling synchronization/replication of all sequences that is useful for
upgrades.
Publications can now include all sequences via FOR ALL SEQUENCES.
psql enhancements:
\d shows publications for a given sequence.
\dRp indicates if a publication includes all sequences.
ALL SEQUENCES can be combined with ALL TABLES, but not with other options
like TABLE or TABLES IN SCHEMA. We can extend support for more granular
clauses in future.
The view pg_publication_sequences provides information about the mapping
between publications and sequences.
This patch enables publishing of sequences; subscriber-side support will
be added in upcoming patches.
Author: vignesh C <vignesh21@gmail.com>
Author: Tomas Vondra <tomas@vondra.me>
Reviewed-by: shveta malik <shveta.malik@gmail.com>
Reviewed-by: Dilip Kumar <dilipbalaut@gmail.com>
Reviewed-by: Peter Smith <smithpb2250@gmail.com>
Reviewed-by: Hayato Kuroda <kuroda.hayato@fujitsu.com>
Reviewed-by: Masahiko Sawada <sawada.mshk@gmail.com>
Reviewed-by: Nisha Moond <nisha.moond412@gmail.com>
Reviewed-by: Shlok Kyal <shlok.kyal.oss@gmail.com>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Discussion: https://postgr.es/m/CAA4eK1LC+KJiAkSrpE_NwvNdidw9F2os7GERUeSxSKv71gXysQ@mail.gmail.com
Eager aggregation is a query optimization technique that partially
pushes aggregation past a join, and finalizes it once all the
relations are joined. Eager aggregation may reduce the number of
input rows to the join and thus could result in a better overall plan.
In the current planner architecture, the separation between the
scan/join planning phase and the post-scan/join phase means that
aggregation steps are not visible when constructing the join tree,
limiting the planner's ability to exploit aggregation-aware
optimizations. To implement eager aggregation, we collect information
about aggregate functions in the targetlist and HAVING clause, along
with grouping expressions from the GROUP BY clause, and store it in
the PlannerInfo node. During the scan/join planning phase, this
information is used to evaluate each base or join relation to
determine whether eager aggregation can be applied. If applicable, we
create a separate RelOptInfo, referred to as a grouped relation, to
represent the partially-aggregated version of the relation and
generate grouped paths for it.
Grouped relation paths can be generated in two ways. The first method
involves adding sorted and hashed partial aggregation paths on top of
the non-grouped paths. To limit planning time, we only consider the
cheapest or suitably-sorted non-grouped paths in this step.
Alternatively, grouped paths can be generated by joining a grouped
relation with a non-grouped relation. Joining two grouped relations
is currently not supported.
To further limit planning time, we currently adopt a strategy where
partial aggregation is pushed only to the lowest feasible level in the
join tree where it provides a significant reduction in row count.
This strategy also helps ensure that all grouped paths for the same
grouped relation produce the same set of rows, which is important to
support a fundamental assumption of the planner.
For the partial aggregation that is pushed down to a non-aggregated
relation, we need to consider all expressions from this relation that
are involved in upper join clauses and include them in the grouping
keys, using compatible operators. This is essential to ensure that an
aggregated row from the partial aggregation matches the other side of
the join if and only if each row in the partial group does. This
ensures that all rows within the same partial group share the same
"destiny", which is crucial for maintaining correctness.
One restriction is that we cannot push partial aggregation down to a
relation that is in the nullable side of an outer join, because the
NULL-extended rows produced by the outer join would not be available
when we perform the partial aggregation, while with a
non-eager-aggregation plan these rows are available for the top-level
aggregation. Pushing partial aggregation in this case may result in
the rows being grouped differently than expected, or produce incorrect
values from the aggregate functions.
If we have generated a grouped relation for the topmost join relation,
we finalize its paths at the end. The final paths will compete in the
usual way with paths built from regular planning.
The patch was originally proposed by Antonin Houska in 2017. This
commit reworks various important aspects and rewrites most of the
current code. However, the original patch and reviews were very
useful.
Author: Richard Guo <guofenglinux@gmail.com>
Author: Antonin Houska <ah@cybertec.at> (in an older version)
Reviewed-by: Robert Haas <robertmhaas@gmail.com>
Reviewed-by: Jian He <jian.universality@gmail.com>
Reviewed-by: Tender Wang <tndrwang@gmail.com>
Reviewed-by: Matheus Alcantara <matheusssilv97@gmail.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: David Rowley <dgrowleyml@gmail.com>
Reviewed-by: Tomas Vondra <tomas@vondra.me> (in an older version)
Reviewed-by: Andy Fan <zhihuifan1213@163.com> (in an older version)
Reviewed-by: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> (in an older version)
Discussion: https://postgr.es/m/CAMbWs48jzLrPt1J_00ZcPZXWUQKawQOFE8ROc-ADiYqsqrpBNw@mail.gmail.com
This patch reuses the existing aggtransspace in pg_aggregate to
signal that an aggregate's transition state can grow unboundedly. If
aggtransspace is set to a negative value, it now indicates that the
transition state may consume unpredictable or large amounts of memory,
such as in aggregates like array_agg or string_agg that accumulate
input rows.
This information can be used by the planner to avoid applying
memory-sensitive optimizations (e.g., eager aggregation) when there is
a risk of excessive memory usage during partial aggregation.
Bump catalog version.
Per idea from Robert Haas, though applied differently than originally
suggested.
Discussion: https://postgr.es/m/CA+TgmoYbkvYwLa+1vOP7RDY7kO2=A7rppoPusoRXe44VDOGBPg@mail.gmail.com
It is possible to call pg_stat_reset_single_function_counters() for a
single function, but the reset time was missing the system view showing
its statistics. Like all the fields of pg_stat_user_functions, the GUC
track_functions needs to be enabled to show the statistics about
function executions.
Bump catalog version.
Bump PGSTAT_FILE_FORMAT_ID, as a result of the new field added to
PgStat_StatFuncEntry.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Discussion: https://postgr.es/m/aONjnsaJSx-nEdfU@paquier.xyz
It is possible to call pg_stat_reset_single_table_counters() on a
relation (index or table) but the reset time was missing from the system
views showing their statistics.
This commit adds the reset time as an attribute of pg_stat_all_tables,
pg_stat_all_indexes, and other relations related to them.
Bump catalog version.
Bump PGSTAT_FILE_FORMAT_ID, as a result of the new field added to
PgStat_StatTabEntry.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Sami Imseih <samimseih@gmail.com>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/aN8l182jKxEq1h9f@paquier.xyz
Add IGNORE NULLS/RESPECT NULLS option (null treatment clause) to lead,
lag, first_value, last_value and nth_value window functions. If
unspecified, the default is RESPECT NULLS which includes NULL values
in any result calculation. IGNORE NULLS ignores NULL values.
Built-in window functions are modified to call new API
WinCheckAndInitializeNullTreatment() to indicate whether they accept
IGNORE NULLS/RESPECT NULLS option or not (the API can be called by
user defined window functions as well). If WinGetFuncArgInPartition's
allowNullTreatment argument is true and IGNORE NULLS option is given,
WinGetFuncArgInPartition() or WinGetFuncArgInFrame() will return
evaluated function's argument expression on specified non NULL row (if
it exists) in the partition or the frame.
When IGNORE NULLS option is given, window functions need to visit and
evaluate same rows over and over again to look for non null rows. To
mitigate the issue, 2-bit not null information array is created while
executing window functions to remember whether the row has been
already evaluated to NULL or NOT NULL. If already evaluated, we could
skip the evaluation work, thus we could get better performance.
Author: Oliver Ford <ojford@gmail.com>
Co-authored-by: Tatsuo Ishii <ishii@postgresql.org>
Reviewed-by: Krasiyan Andreev <krasiyan@gmail.com>
Reviewed-by: Andrew Gierth <andrew@tao11.riddles.org.uk>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: David Fetter <david@fetter.org>
Reviewed-by: Vik Fearing <vik@postgresfriends.org>
Reviewed-by: "David G. Johnston" <david.g.johnston@gmail.com>
Reviewed-by: Chao Li <lic@highgo.com>
Discussion: https://postgr.es/m/flat/CAGMVOdsbtRwE_4+v8zjH1d9xfovDeQAGLkP_B6k69_VoFEgX-A@mail.gmail.com
Move the checks out of the Makefile into a perl script that can be
called from both the Makefile and meson.build. The set of files checked
is simplified, so it is just all the sgml and xsl files found in
docs/src/sgml directory tree.
Along the way make some adjustments to .cirrus.tasks.yml to support this
better in CI.
Also ensure that the checks are part of the Makefile's html target.
Author: Nazir Bilal Yavuz <byavuz81@gmail.com>
Co-Author: Andrew Dunstan <andrew@dunslane.net>
Discussion: https://postgr.es/m/CAN55FZ3BnM+0twT-ZWL8As9oBEte_b+SBU==cz6Hk8JUCM_5Wg@mail.gmail.com
GROUP BY ALL is a form of GROUP BY that adds any TargetExpr that does
not contain an aggregate or window function into the groupClause of
the query, making it exactly equivalent to specifying those same
expressions in an explicit GROUP BY list.
This feature is useful for certain kinds of data exploration. It's
already present in some other DBMSes, and the SQL committee recently
accepted it into the standard, so we can be reasonably confident in
the syntax being stable. We do have to invent part of the semantics,
as the standard doesn't allow for expressions in GROUP BY, so they
haven't specified what to do with window functions. We assume that
those should be treated like aggregates, i.e., left out of the
constructed GROUP BY list.
In passing, wordsmith some existing documentation about GROUP BY,
and update some neglected synopsis entries in select_into.sgml.
Author: David Christensen <david@pgguru.net>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/CAHM0NXjz0kDwtzoe-fnHAqPB1qA8_VJN0XAmCgUZ+iPnvP5LbA@mail.gmail.com
These were omitted from build dependencies and also tab/nbsp
checks, with the result that "make" did nothing after modifying
a func/*.sgml file.
Oversight in 4e23c9ef6. AFAICT we don't need any comparable
changes in meson.build, or at least I don't see it doing anything
special for the pre-existing ref/*.sgml files.
This commit updates the pgbench documentation to list \gset and \aset
as separate terms for easier reading. It also clarifies that \gset raises
an error if the query returns zero or multiple rows, and explains how to
detect cases where the query with \aset returned no rows.
Author: Yugo Nagata <nagata@sraoss.co.jp>
Reviewed-by: Fujii Masao <masao.fujii@gmail.com>
Discussion: https://postgr.es/m/20250626180125.5b896902a3d0bcd93f86c240@sraoss.co.jp
Mappings for 18 characters have changed, affecting 36 code points. This
is a break in compatibility, but these characters are rarely used.
U+E5E5 (Private Use Area) was previously mapped to \xA3A0. This code
point now maps to \x65356535. Attempting to convert \xA3A0 will now
raise an error.
Separate from the 2022 update, the following mappings were previously
swapped, and subsequently corrected in 2000 and later versions:
* U+E7C7 (Private Use Area) now maps to \x8135F437
* U+1E3F (Latin Small Letter M with Acute) now maps to \xA8BC
The 2022 standard mentions the following policy changes, but they
have no effect in our implementation:
66 new ideographs are now required, but these are mapped
algorithmically so were already handled by utf8_and_gb18030.c.
Nine CJK compatibility ideographs are no longer required, but
implementations may retain them, as does the source we use from
the Unicode Consortium.
Release notes: Compatibility section
For further details, see:
https://www.unicode.org/L2/L2022/22274-disruptive-changes.pdfhttps://ken-lunde.medium.com/the-gb-18030-2022-standard-3d0ebaeb4132
Author: Chao Li <lic@highgo.com>
Author: Zheng Tao <taoz@highgo.com>
Discussion: https://postgr.es/m/966d9fc.169.198741fe60b.Coremail.jiaoshuntian%40highgo.com
Remove stray whitespace in xref tag.
This was found due to a regression in xmllint 2.15.0 which flagged
this as an error, and at the time of this commit no fix for xmllint
has shipped.
Author: Erik Wienhold <ewie@ewie.name>
Discussion: https://postgr.es/m/f4c4661b-4e60-4c10-9336-768b7b55c084@ewie.name
Backpatch-through: 17
Commit 216a784829 introduced parallel apply workers, allowing multiple
processes to share a replication origin. To support this,
replorigin_session_setup() was extended to accept a pid argument
identifying the process using the origin.
This commit exposes that capability through the SQL interface function
pg_replication_origin_session_setup() by adding an optional pid parameter.
This enables multiple processes to coordinate replication using the same
origin when using SQL-level replication functions.
This change allows the non-builtin logical replication solutions to
implement parallel apply for large transactions.
Additionally, an existing internal error was made user-facing, as it can
now be triggered via the exposed SQL API.
Author: Doruk Yilmaz <doruk@mixrank.com>
Author: Hayato Kuroda <kuroda.hayato@fujitsu.com>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Reviewed-by: Euler Taveira <euler@eulerto.com>
Discussion: https://postgr.es/m/CAMPB6wfe4zLjJL8jiZV5kjjpwBM2=rTRme0UCL7Ra4L8MTVdOg@mail.gmail.com
Discussion: https://postgr.es/m/CAE2gYzyTSNvHY1+iWUwykaLETSuAZsCWyryokjP6rG46ZvRgQA@mail.gmail.com
This reverts commit 98fc31d649.
That change allowed DROP OWNED BY to drop grants of the target
role to other roles, arguing that nobody would need those
privileges anymore. But that's not so: if you're not superuser,
you still need admin privilege on the target role so you can
drop it.
It's not clear whether or how the dependency-based approach
to solving the original problem can be adapted to keep these
grants. Since v18 release is fast approaching, the sanest
thing to do seems to be to revert this patch for now. The
race-condition problem is low severity and not worth taking
risks for.
I didn't force a catversion bump in 98fc31d64, so I won't do
so here either.
Reported-by: Dipesh Dhameliya <dipeshdhameliya125@gmail.com>
Author: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/CABgZEgczOFicCJoqtrH9gbYMe_BV3Hq8zzCBRcMgmU6LRsihUA@mail.gmail.com
Backpatch-through: 18
Up to now we've contented ourselves with a one-size-fits-all error
hint when we fail to find any match to a function or procedure call.
That was mostly okay in the beginning, but it was never great, and
since the introduction of named arguments it's really not adequate.
We at least ought to distinguish "function name doesn't exist" from
"function name exists, but not with those argument names". And the
rules for named-argument matching are arcane enough that some more
detail seems warranted if we match the argument names but the call
still doesn't work.
This patch creates a framework for dealing with these problems:
FuncnameGetCandidates and related code will now pass back a bitmask of
flags showing how far the match succeeded. This allows a considerable
amount of granularity in the reports. The set-bits-in-a-bitmask
approach means that when there are multiple candidate functions, the
report will reflect the match(es) that got the furthest, which seems
correct. Also, we can avoid mentioning "maybe add casts" unless
failure to match argument types is actually the issue.
Extend the same return-a-bitmask approach to OpernameGetCandidates.
The issues around argument names don't apply to operator syntax,
but it still seems worth distinguishing between "there is no
operator of that name" and "we couldn't match the argument types".
While at it, adjust these messages and related ones to more strictly
separate "detail" from "hint", following our message style guidelines'
distinction between those.
Reported-by: Dominique Devienne <ddevienne@gmail.com>
Author: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Robert Haas <robertmhaas@gmail.com>
Discussion: https://postgr.es/m/1756041.1754616558@sss.pgh.pa.us
This commit resumes automatic retention of conflict-relevant data for a
subscription. Previously, retention would stop if the apply process failed
to advance its xmin (oldest_nonremovable_xid) within the configured
max_retention_duration and user needs to manually re-enable
retain_dead_tuples option. With this change, retention will resume
automatically once the apply worker catches up and begins advancing its
xmin (oldest_nonremovable_xid) within the configured threshold.
Author: Zhijie Hou <houzj.fnst@fujitsu.com>
Reviewed-by: shveta malik <shveta.malik@gmail.com>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Reviewed-by: Dilip Kumar <dilipbalaut@gmail.com>
Reviewed-by: Masahiko Sawada <sawada.mshk@gmail.com>
Discussion: https://postgr.es/m/OS0PR01MB5716BE80DAEB0EE2A6A5D1F5949D2@OS0PR01MB5716.jpnprd01.prod.outlook.com
If extensions of equal names were installed in different directories
in the path, the views pg_available_extensions and
pg_available_extension_versions would show all of them, even though
only the first one was actually reachable by CREATE EXTENSION. To
fix, have those views skip extensions found later in the path if they
have names already found earlier.
Also add a bit of documentation that only the first extension in the
path can be used.
Reported-by: Pierrick <pierrick.chovelon@dalibo.com>
Discussion: https://www.postgresql.org/message-id/flat/8f5a0517-1cb8-4085-ae89-77e7454e27ba%40dalibo.com
This commit allows to log the raw parse tree in the same way we
currently log the parse tree, rewritten tree, and plan tree.
To avoid unnecessary log noise for users not interested in this
detail, a new GUC option, "debug_print_raw_parse", has been added.
When starting the PostgreSQL process with "-d N", and N is 3 or higher,
debug_print_raw_parse is enabled automatically, alongside
debug_print_parse.
Author: Chao Li <lic@highgo.com>
Reviewed-by: Tender Wang <tndrwang@gmail.com>
Reviewed-by: Tatsuo Ishii <ishii@postgresql.org>
Reviewed-by: John Naylor <johncnaylorls@gmail.com>
Discussion: https://postgr.es/m/CAEoWx2mcO0Gpo4vd8kPMAFWeJLSp0MeUUnaLdE1x0tSVd-VzUw%40mail.gmail.com
There are two ways for shared libraries to allocate their own
LWLock tranches. One way is to call RequestNamedLWLockTranche() in
a shmem_request_hook, which requires the library to be loaded via
shared_preload_libraries. The other way is to call
LWLockNewTrancheId(), which is not subject to the same
restrictions. However, LWLockNewTrancheId() does require each
backend to store the tranche's name in backend-local memory via
LWLockRegisterTranche(). This API is a little cumbersome and leads
to things like unhelpful pg_stat_activity.wait_event values in
backends that haven't loaded the library.
This commit moves these LWLock tranche names to shared memory, thus
eliminating the need for each backend to call
LWLockRegisterTranche(). Instead, the tranche name must be
provided to LWLockNewTrancheId(), which immediately makes the name
available to all backends. Since the tranche name array is
append-only, lookups can ordinarily avoid locking as long as their
local copy of the LWLock counter is greater than the requested
tranche ID.
One downside of this approach is that we now have a hard limit on
both the length of tranche names (NAMEDATALEN-1 bytes) and the
number of dynamically-allocated tranches (256). Besides a limit of
NAMEDATALEN-1 bytes for tranche names registered via
RequestNamedLWLockTranche(), no such limits previously existed. We
could avoid these new limits by using dynamic shared memory, but
the complexity involved didn't seem worth it. We briefly
considered making the tranche limit user-configurable but
ultimately decided against that, too. Since there is still a lot
of time left in the v19 development cycle, it's possible we will
revisit this choice.
Author: Sami Imseih <samimseih@gmail.com>
Reviewed-by: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Rahila Syed <rahilasyed90@gmail.com>
Reviewed-by: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/CAA5RZ0vvED3naph8My8Szv6DL4AxOVK3eTPS0qXsaKi%3DbVdW2A%40mail.gmail.com
