Historically, the statistics of the checkpointer have been always part
of pg_stat_bgwriter. This commit removes a few columns from
pg_stat_bgwriter, and introduces pg_stat_checkpointer with equivalent,
renamed columns (plus a new one for the reset timestamp):
- checkpoints_timed -> num_timed
- checkpoints_req -> num_requested
- checkpoint_write_time -> write_time
- checkpoint_sync_time -> sync_time
- buffers_checkpoint -> buffers_written
The fields of PgStat_CheckpointerStats and its SQL functions are renamed
to match with the new field names, for consistency. Note that
background writer and checkpointer have been split into two different
processes in commits 806a2aee37 and bf405ba8e4. The pgstat
structures were already split, making this change straight-forward.
Bump catalog version.
Author: Bharath Rupireddy
Reviewed-by: Bertrand Drouvot, Andres Freund, Michael Paquier
Discussion: https://postgr.es/m/CALj2ACVxX2ii=66RypXRweZe2EsBRiPMj0aHfRfHUeXJcC7kHg@mail.gmail.com
The original code did very little to guard against integer or floating
point overflow when computing the interval's fields. Detect any such
overflows and error out, rather than silently returning bogus results.
Joseph Koshakow, reviewed by Ashutosh Bapat and me.
Discussion: https://postgr.es/m/CAAvxfHcm1TPwH_zaGWuFoL8pZBestbRZTU6Z%3D-RvAdSXTPbKfg%40mail.gmail.com
d3d55ce571 changed RelOptInfo.unique_for_rels from the list of Relid sets to
the list of UniqueRelInfo's. But it didn't make UniqueRelInfo a node.
This commit makes UniqueRelInfo a node. Also this commit revises some
comments related to RelOptInfo.unique_for_rels.
Reported-by: Tom Lane
Discussion: https://postgr.es/m/flat/1189851.1698340331%40sss.pgh.pa.us
Two attributes related to checkpointer statistics are removed in this
commit:
- buffers_backend, that counts the number of buffers written directly by
a backend.
- buffers_backend_fsync, that counts the number of times a backend had
to do fsync() by its own.
These are actually not checkpointer properties but backend properties.
Also, pg_stat_io provides a more accurate and equivalent report of these
numbers, by tracking all the I/O stats related to backends, including
writes and fsyncs, so storing them in pg_stat_checkpointer was
redundant.
Thanks also to Robert Haas and Amit Kapila for their input.
Bump catalog version.
Author: Bharath Rupireddy
Reviewed-by: Bertrand Drouvot, Andres Freund
Discussion: https://postgr.es/m/20230210004604.mcszbscsqs3bc5nx@awork3.anarazel.de
Since C99, there can be a trailing comma after the last value in an
enum definition. A lot of new code has been introducing this style on
the fly. Some new patches are now taking an inconsistent approach to
this. Some add the last comma on the fly if they add a new last
value, some are trying to preserve the existing style in each place,
some are even dropping the last comma if there was one. We could
nudge this all in a consistent direction if we just add the trailing
commas everywhere once.
I omitted a few places where there was a fixed "last" value that will
always stay last. I also skipped the header files of libpq and ecpg,
in case people want to use those with older compilers. There were
also a small number of cases where the enum type wasn't used anywhere
(but the enum values were), which ended up confusing pgindent a bit,
so I left those alone.
Discussion: https://www.postgresql.org/message-id/flat/386f8c45-c8ac-4681-8add-e3b0852c1620%40eisentraut.org
There were various places in our codebase which conjured up a StringInfo
by manually assigning the StringInfo fields and setting the data field
to point to some existing buffer. There wasn't much consistency here as
to what fields like maxlen got set to and in one location we didn't
correctly ensure that the buffer was correctly NUL terminated at len
bytes, as per what was documented as required in stringinfo.h
Here we introduce 2 new functions to initialize StringInfos. One allows
callers to initialize a StringInfo passing along a buffer that is
already allocated by palloc. Here the StringInfo code uses this buffer
directly rather than doing any memcpying into a new allocation. Having
this as a function allows us to verify the buffer is correctly NUL
terminated. StringInfos initialized this way can be appended to and
reset just like any other normal StringInfo.
The other new initialization function also accepts an existing buffer,
but the given buffer does not need to be a pointer to a palloc'd chunk.
This buffer could be a pointer pointing partway into some palloc'd chunk
or may not even be palloc'd at all. StringInfos initialized this way
are deemed as "read-only". This means that it's not possible to
append to them or reset them.
For the latter of the two new initialization functions mentioned above,
we relax the requirement that the data buffer must be NUL terminated.
Relaxing this requirement is convenient in a few places as it can save
us from having to allocate an entire new buffer just to add the NUL
terminator or save us from having to temporarily add a NUL only to have to
put the original char back again later.
Incompatibility note:
Here we also forego adding the NUL in a few places where it does not
seem to be required. These locations are passing the given StringInfo
into a type's receive function. It does not seem like any of our
built-in receive functions require this, but perhaps there's some UDT
out there in the wild which does require this. It is likely worthy of
a mention in the release notes that a UDT's receive function mustn't rely
on the input StringInfo being NUL terminated.
Author: David Rowley
Reviewed-by: Tom Lane
Discussion: https://postgr.es/m/CAApHDvorfO3iBZ%3DxpiZvp3uHtJVLyFaPBSvcAhAq2HPLnaNSwQ%40mail.gmail.com
While reading information from the old cluster, a list of logical
slots is fetched. At the later part of upgrading, pg_upgrade revisits the
list and restores slots by executing pg_create_logical_replication_slot()
on the new cluster. Migration of logical replication slots is only
supported when the old cluster is version 17.0 or later.
If the old node has invalid slots or slots with unconsumed WAL records,
the pg_upgrade fails. These checks are needed to prevent data loss.
The significant advantage of this commit is that it makes it easy to
continue logical replication even after upgrading the publisher node.
Previously, pg_upgrade allowed copying publications to a new node. With
this patch, adjusting the connection string to the new publisher will
cause the apply worker on the subscriber to connect to the new publisher
automatically. This enables seamless continuation of logical replication,
even after an upgrade.
Author: Hayato Kuroda, Hou Zhijie
Reviewed-by: Peter Smith, Bharath Rupireddy, Dilip Kumar, Vignesh C, Shlok Kyal
Discussion: http://postgr.es/m/TYAPR01MB58664C81887B3AF2EB6B16E3F5939@TYAPR01MB5866.jpnprd01.prod.outlook.com
Discussion: http://postgr.es/m/CAA4eK1+t7xYcfa0rEQw839=b2MzsfvYDPz3xbD+ZqOdP3zpKYg@mail.gmail.com
The Self Join Elimination (SJE) feature removes an inner join of a plain table
to itself in the query tree if is proved that the join can be replaced with
a scan without impacting the query result. Self join and inner relation are
replaced with the outer in query, equivalence classes, and planner info
structures. Also, inner restrictlist moves to the outer one with removing
duplicated clauses. Thus, this optimization reduces the length of the range
table list (this especially makes sense for partitioned relations), reduces
the number of restriction clauses === selectivity estimations, and potentially
can improve total planner prediction for the query.
The SJE proof is based on innerrel_is_unique machinery.
We can remove a self-join when for each outer row:
1. At most one inner row matches the join clause.
2. Each matched inner row must be (physically) the same row as the outer one.
In this patch we use the next approach to identify a self-join:
1. Collect all merge-joinable join quals which look like a.x = b.x
2. Add to the list above the baseretrictinfo of the inner table.
3. Check innerrel_is_unique() for the qual list. If it returns false, skip
this pair of joining tables.
4. Check uniqueness, proved by the baserestrictinfo clauses. To prove
the possibility of self-join elimination inner and outer clauses must have
an exact match.
The relation replacement procedure is not trivial and it is partly combined
with the one, used to remove useless left joins. Tests, covering this feature,
were added to join.sql. Some regression tests changed due to self-join removal
logic.
Discussion: https://postgr.es/m/flat/64486b0b-0404-e39e-322d-0801154901f3%40postgrespro.ru
Author: Andrey Lepikhov, Alexander Kuzmenkov
Reviewed-by: Tom Lane, Robert Haas, Andres Freund, Simon Riggs, Jonathan S. Katz
Reviewed-by: David Rowley, Thomas Munro, Konstantin Knizhnik, Heikki Linnakangas
Reviewed-by: Hywel Carver, Laurenz Albe, Ronan Dunklau, vignesh C, Zhihong Yu
Reviewed-by: Greg Stark, Jaime Casanova, Michał Kłeczek, Alena Rybakina
Reviewed-by: Alexander Korotkov
When an UPDATE/DELETE/MERGE's target table is an old-style
inheritance tree, it's possible for the parent to get excluded
from the plan while some children are not. (I believe this is
only possible if we can prove that a CHECK ... NO INHERIT
constraint on the parent contradicts the query WHERE clause,
so it's a very unusual case.) In such a case, ExecInitModifyTable
mistakenly concluded that the first surviving child is the target
table, leading to at least two bugs:
1. The wrong table's statement-level triggers would get fired.
2. In v16 and up, it was possible to fail with "invalid perminfoindex
0 in RTE with relid nnnn" due to the child RTE not having permissions
data included in the query plan. This was hard to reproduce reliably
because it did not occur unless the update triggered some non-HOT
index updates.
In v14 and up, this is easy to fix by defining ModifyTable.rootRelation
to be the parent RTE in plain inheritance as well as partitioned cases.
While the wrong-triggers bug also appears in older branches, the
relevant code in both the planner and executor is quite a bit
different, so it would take a good deal of effort to develop and
test a suitable patch. Given the lack of field complaints about the
trigger issue, I'll desist for now. (Patching v11 for this seems
unwise anyway, given that it will have no more releases after next
month.)
Per bug #18147 from Hans Buschmann.
Amit Langote and Tom Lane
Discussion: https://postgr.es/m/18147-6fc796538913ee88@postgresql.org
Enforce the rule from transam/README in XLogRegisterBuffer(), and
update callers to follow the rule.
Hash indexes sometimes register clean pages as a part of the locking
protocol, so provide a REGBUF_NO_CHANGE flag to support that use.
Discussion: https://postgr.es/m/c84114f8-c7f1-5b57-f85a-3adc31e1a904@iki.fi
Reviewed-by: Heikki Linnakangas
This shouldn't change behavior except in the unusual case where
there are file in the tablespace directory that have entirely
numeric names but are nevertheless not possible names for a
tablespace directory, either because their names have leading zeroes
that shouldn't be there, or the value is actually zero, or because
the value is too large to represent as an OID.
In those cases, the directory would previously have made it into
the list of tablespaceinfo objects and no longer will. Thus, base
backups will now ignore such directories, instead of treating them
as legitimate tablespace directories. Similarly, if entries for
such tablespaces occur in a tablespace_map file, they will now
be rejected as erroneous, instead of being honored.
This is infrastructure for future work that wants to be able to
know the tablespace of each relation that is part of a backup
*as an OID*. By strengthening the up-front validation, we don't
have to worry about weird cases later, and can more easily avoid
repeated string->integer conversions.
Patch by me, reviewed by David Steele.
Discussion: http://postgr.es/m/CA+TgmoZNVeBzoqDL8xvr-nkaepq815jtDR4nJzPew7=3iEuM1g@mail.gmail.com
Instead of returning the number of characters in the RelFileNumber,
return the RelFileNumber itself. Continue to return the fork number,
as before, and additionally return the segment number.
parse_filename_for_nontemp_relation now rejects a RelFileNumber or
segment number that begins with a leading zero. Before, we accepted
such cases as relation filenames, but if we continued to do so after
this change, the function might return the same values for two
different files (e.g. 1234.5 and 001234.5 or 1234.005) which could be
annoying for callers. Since we don't actually ever generate filenames
with leading zeroes in the names, any such files that we find must
have been created by something other than PostgreSQL, and it is
therefore reasonable to treat them as non-relation files.
Along the way, change unlogged_relation_entry to store a RelFileNumber
rather than an OID. This update should have been made in
851f4cc75c, but it was overlooked.
It's trivial to make the update as part of this commit, perhaps more
trivial than it would have been without it, so do that.
Patch by me, reviewed by David Steele.
Discussion: http://postgr.es/m/CA+TgmoZNVeBzoqDL8xvr-nkaepq815jtDR4nJzPew7=3iEuM1g@mail.gmail.com
Previously, ALTER SYSTEM failed if the target GUC wasn't present in
the session's GUC hashtable. That is a reasonable behavior for core
(single-part) GUC names, and for custom GUCs for which we have loaded
an extension that's reserved the prefix. But it's unnecessarily
restrictive otherwise, and it also causes inconsistent behavior:
you can "ALTER SYSTEM SET foo.bar" only if you did "SET foo.bar"
earlier in the session. That's fairly silly.
Hence, refactor things so that we can execute ALTER SYSTEM even
if the variable doesn't have a GUC hashtable entry, as long as the
name meets the custom-variable naming requirements and does not
have a reserved prefix. (It's safe to do this even if the
variable belongs to an extension we currently don't have loaded.
A bad value will at worst cause a WARNING when the extension
does get loaded.)
Also, adjust GRANT ON PARAMETER to have the same opinions about
whether to allow an unrecognized GUC name, and to throw the
same errors if not (it previously used a one-size-fits-all
message for several distinguishable conditions). By default,
only a superuser will be allowed to do ALTER SYSTEM SET on an
unrecognized name, but it's possible to GRANT the ability to
do it.
Patch by me, pursuant to a documentation complaint from
Gavin Panella. Arguably this is a bug fix, but given the
lack of other complaints I'll refrain from back-patching.
Discussion: https://postgr.es/m/2617358.1697501956@sss.pgh.pa.us
Discussion: https://postgr.es/m/169746329791.169914.16613647309012285391@wrigleys.postgresql.org
Allow the COMMUTATOR, NEGATOR, MERGES, and HASHES attributes to be set
by ALTER OPERATOR. However, we don't allow COMMUTATOR/NEGATOR to be
changed once set, nor allow the MERGES/HASHES flags to be unset once
set. Changes like that might invalidate plans already made, and
dealing with the consequences seems like more trouble than it's worth.
The main use-case we foresee for this is to allow addition of missed
properties in extension update scripts, such as extending an existing
operator to support hashing. So only transitions from not-set to set
states seem very useful.
This patch also causes us to reject some incorrect cases that formerly
resulted in inconsistent catalog state, such as trying to set the
commutator of an operator to be some other operator that already has a
(different) commutator.
While at it, move the InvokeObjectPostCreateHook call for CREATE
OPERATOR to not occur until after we've fixed up commutator or negator
links as needed. The previous ordering could only be justified by
thinking of the OperatorUpd call as a kind of ALTER OPERATOR step;
but we don't call InvokeObjectPostAlterHook therein. It seems better
to let the hook see the final state of the operator object.
In the documentation, move the discussion of how to establish
commutator pairs from xoper.sgml to the CREATE OPERATOR ref page.
Tommy Pavlicek, reviewed and editorialized a bit by me
Discussion: https://postgr.es/m/CAEhP-W-vGVzf4udhR5M8Bdv88UYnPrhoSkj3ieR3QNrsGQoqdg@mail.gmail.com
This allows tools that read the WAL sequentially to identify (possible)
redo points when they're reached, rather than only being able to
detect them in retrospect when XLOG_CHECKPOINT_ONLINE is found, possibly
much later in the WAL stream. There are other possible applications as
well; see the discussion links below.
Any redo location that precedes the checkpoint location should now point
to an XLOG_CHECKPOINT_REDO record, so add a cross-check to verify this.
While adjusting the code in CreateCheckPoint() for this patch, I made it
call WALInsertLockAcquireExclusive a bit later than before, since there
appears to be no need for it to be held while checking whether the system
is idle, whether this is an end-of-recovery checkpoint, or what the current
timeline is.
Bump XLOG_PAGE_MAGIC.
Patch by me, based in part on earlier work from Dilip Kumar. Review by
Dilip Kumar, Amit Kapila, Andres Freund, and Michael Paquier.
Discussion: http://postgr.es/m/CA+TgmoYy-Vc6G9QKcAKNksCa29cv__czr+N9X_QCxEfQVpp_8w@mail.gmail.com
Discussion: http://postgr.es/m/20230614194717.jyuw3okxup4cvtbt%40awork3.anarazel.de
Discussion: http://postgr.es/m/CA+hUKG+b2ego8=YNW2Ohe9QmSiReh1-ogrv8V_WZpJTqP3O+2w@mail.gmail.com
There was no I/O timing statistics for counting read and write timings
on local blocks, contrary to the counterparts for temp and shared
blocks. This information is available when track_io_timing is enabled.
The output of EXPLAIN is updated to show this information. An update of
pg_stat_statements is planned next.
Author: Nazir Bilal Yavuz
Reviewed-by: Robert Haas, Melanie Plageman
Discussion: https://postgr.es/m/CAN55FZ19Ss279mZuqGbuUNxka0iPbLgYuOQXqAKewrjNrp27VA@mail.gmail.com
These two counters, defined in BufferUsage to track respectively the
time spent while reading and writing blocks have historically only
tracked data related to shared buffers, when track_io_timing is enabled.
An upcoming patch to add specific counters for local buffers will take
advantage of this rename as it has come up that no data is currently
tracked for local buffers, and tracking local and shared buffers using
the same fields would be inconsistent with the treatment done for temp
buffers. Renaming the existing fields clarifies what the block type of
each stats field is.
pg_stat_statement is updated to reflect the rename. No extension
version bump is required as 5a3423ad8e has done one, affecting v17~.
Author: Nazir Bilal Yavuz
Reviewed-by: Robert Haas, Melanie Plageman
Discussion: https://postgr.es/m/CAN55FZ19Ss279mZuqGbuUNxka0iPbLgYuOQXqAKewrjNrp27VA@mail.gmail.com
An extra rule is needed in src/include/Makefile for VPATH builds to
install any generated server-side include files, and wait_event_types.h
was forgotten from the set.
Issue introduced by fa88928470.
Reported-by: Christoph Berg
Discussion: https://postgr.es/m/ZTAA11u7CtX6NqlK@msg.df7cb.de
Remove use of LLVMGetElementType() and provide the type of all pointers
to LLVMBuildXXX() functions when emitting IR, as required by modern LLVM
versions[1].
* For LLVM <= 14, we'll still use the old LLVMBuildXXX() functions.
* For LLVM == 15, we'll continue to do the same, explicitly opting
out of opaque pointer mode.
* For LLVM >= 16, we'll use the new LLVMBuildXXX2() functions that take
the extra type argument.
The difference is hidden behind some new IR emitting wrapper functions
l_load(), l_gep(), l_call() etc. The change is mostly mechanical,
except that at each site the correct type had to be provided.
In some places we needed to do some extra work to get functions types,
including some new wrappers for C++ APIs that are not yet exposed by in
LLVM's C API, and some new "example" functions in llvmjit_types.c
because it's no longer possible to start from the function pointer type
and ask for the function type.
Back-patch to 12, because it's a little tricker in 11 and we agreed not
to put the latest LLVM support into the upcoming final release of 11.
[1] https://llvm.org/docs/OpaquePointers.html
Reviewed-by: Dmitry Dolgov <9erthalion6@gmail.com>
Reviewed-by: Ronan Dunklau <ronan.dunklau@aiven.io>
Reviewed-by: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/CA%2BhUKGKNX_%3Df%2B1C4r06WETKTq0G4Z_7q4L4Fxn5WWpMycDj9Fw%40mail.gmail.com
Since its introduction, LogLogicalMessage() (via the SQL interface
pg_logical_emit_message()) has never included a call to XLogFlush(),
causing it to potentially lose messages on a crash when used in
non-transactional mode. This has come up to me as a problem while
playing with ideas to design a test suite for what has become
039_end_of_wal.pl introduced in bae868caf2 by Thomas Munro, because
there are no direct ways to force a WAL flush via SQL.
The default is false, to not flush messages and influence existing
use-cases where this function could be used. If set to true, the
message emitted is flushed before returning back to the caller, making
the message durable on crash. This new option has no effect when using
pg_logical_emit_message() in transactional mode, as the record's flush
is guaranteed by the WAL record generated by the transaction committed.
Two queries of test_decoding are tweaked to cover the new code path for
the flush.
Bump catalog version.
Author: Michael Paquier
Reviewed-by: Andres Freund, Amit Kapila, Fujii Masao, Tung Nguyen, Tomas
Vondra
Discussion: https://postgr.es/m/ZNsdThSe2qgsfs7R@paquier.xyz
The SIGTERM handler for the startup process immediately calls
proc_exit() for the duration of the restore_command, i.e., a call
to system(). This system() call forks a new process to execute the
shell command, and this child process inherits the parent's signal
handlers. If both the parent and child processes receive SIGTERM,
both will attempt to call proc_exit(). This can end badly. For
example, both processes will try to remove themselves from the
PGPROC shared array.
To fix this problem, this commit adds a check in
StartupProcShutdownHandler() to see whether MyProcPid == getpid().
If they match, this is the parent process, and we can proc_exit()
like before. If they do not match, this is a child process, and we
just emit a message to STDERR (in a signal safe manner) and
_exit(), thereby skipping any problematic exit callbacks.
This commit also adds checks in proc_exit(), ProcKill(), and
AuxiliaryProcKill() that verify they are not being called within
such child processes.
Suggested-by: Andres Freund
Reviewed-by: Thomas Munro, Andres Freund
Discussion: https://postgr.es/m/Y9nGDSgIm83FHcad%40paquier.xyz
Discussion: https://postgr.es/m/20230223231503.GA743455%40nathanxps13
Backpatch-through: 11
Restart the apply worker if the subscription owner's superuser privileges
have been revoked. This is required so that the subscription connection
string gets revalidated and use the password option to connect to the
publisher for non-superusers, if required.
Author: Vignesh C
Reviewed-by: Amit Kapila
Discussion: http://postgr.es/m/CALDaNm2Dxmhq08nr4P6G+24QvdBo_GAVyZ_Q1TcGYK+8NHs9xw@mail.gmail.com
This commit introduces trigger on login event, allowing to fire some actions
right on the user connection. This can be useful for logging or connection
check purposes as well as for some personalization of environment. Usage
details are described in the documentation included, but shortly usage is
the same as for other triggers: create function returning event_trigger and
then create event trigger on login event.
In order to prevent the connection time overhead when there are no triggers
the commit introduces pg_database.dathasloginevt flag, which indicates database
has active login triggers. This flag is set by CREATE/ALTER EVENT TRIGGER
command, and unset at connection time when no active triggers found.
Author: Konstantin Knizhnik, Mikhail Gribkov
Discussion: https://postgr.es/m/0d46d29f-4558-3af9-9c85-7774e14a7709%40postgrespro.ru
Reviewed-by: Pavel Stehule, Takayuki Tsunakawa, Greg Nancarrow, Ivan Panchenko
Reviewed-by: Daniel Gustafsson, Teodor Sigaev, Robert Haas, Andres Freund
Reviewed-by: Tom Lane, Andrey Sokolov, Zhihong Yu, Sergey Shinderuk
Reviewed-by: Gregory Stark, Nikita Malakhov, Ted Yu
Under interval_ops, some equal values are distinguishable. One such
pair is '24:00:00' and '1 day'. With that being so, btequalimage()
breaches the documented contract for the "equalimage" btree support
function. This can cause incorrect results from index-only scans.
Users should REINDEX any btree indexes having interval-type columns.
After updating, pg_amcheck will report an error for almost all such
indexes. This fix makes interval_ops simply omit the support function,
like numeric_ops does. Back-pack to v13, where btequalimage() first
appeared. In back branches, for the benefit of old catalog content,
btequalimage() code will return false for type "interval". Going
forward, back-branch initdb will include the catalog change.
Reviewed by Peter Geoghegan.
Discussion: https://postgr.es/m/20231011013317.22.nmisch@google.com
For the same reasons given in commit 403ac226d, adjust these
functions to not assume that checking SearchSysCacheExists can
guarantee success of a later fetch.
This follows the same internal API choices made in the earlier commit:
add a function XXXExt(oid, is_missing) and use that to eliminate
the need for a separate existence check. The changes are very
straightforward, though tedious. For the moment I just made the new
functions static in namespace.c, but we could export them if a need
emerges.
Per bug #18014 from Alexander Lakhin. Given the lack of hard evidence
that there's a bug in non-debug builds, I'm content to fix this only
in HEAD.
Discussion: https://postgr.es/m/18014-28c81cb79d44295d@postgresql.org
The versions of these functions that accept object OIDs are supposed
to return NULL, rather than failing, if the target object has been
dropped. This makes it safe(r) to use them in queries that scan
catalogs, since the functions will be applied to objects that are
visible in the query's snapshot but might now be gone according to
the catalog snapshot. In most cases we implemented this by doing
a SearchSysCacheExists test and assuming that if that succeeds, we
can safely invoke the appropriate aclchk.c function, which will
immediately re-fetch the same syscache entry. It was argued that
if the existence test succeeds then the followup fetch must succeed
as well, for lack of any intervening AcceptInvalidationMessages call.
Alexander Lakhin demonstrated that this is not so when
CATCACHE_FORCE_RELEASE is enabled: the syscache entry will be forcibly
dropped at the end of SearchSysCacheExists, and then it is possible
for the catalog snapshot to get advanced while re-fetching the entry.
Alexander's test case requires the operation to happen inside a
parallel worker, but that seems incidental to the fundamental problem.
What remains obscure is whether there is a way for this to happen in a
non-debug build. Nonetheless, CATCACHE_FORCE_RELEASE is a very useful
test methodology, so we'd better make the code safe for it.
After some discussion we concluded that the most future-proof fix
is to give up the assumption that checking SearchSysCacheExists can
guarantee success of a later fetch. At best that assumption leads
to fragile code --- for example, has_type_privilege appears broken
for array types even if you believe the assumption holds. And it's
not even particularly efficient.
There had already been some work towards extending the aclchk.c
APIs to include "is_missing" output flags, so this patch extends
that work to cover all the aclchk.c functions that are used by the
has_xxx_privilege() functions. (This allows getting rid of some
ad-hoc decisions about not throwing errors in certain places in
aclchk.c.)
In passing, this fixes the has_sequence_privilege() functions to
provide the same guarantees as their cousins: for some reason the
SearchSysCacheExists tests never got added to those.
There is more work to do to remove the unsafe coding pattern with
SearchSysCacheExists in other places, but this is a pretty
self-contained patch so I'll commit it separately.
Per bug #18014 from Alexander Lakhin. Given the lack of hard evidence
that there's a bug in non-debug builds, I'm content to fix this only
in HEAD. (Perhaps we should clean up the has_sequence_privilege()
oversight in the back branches, but in the absence of field complaints
I'm not too excited about that either.)
Discussion: https://postgr.es/m/18014-28c81cb79d44295d@postgresql.org
* sync_method is renamed to wal_sync_method.
* sync_method_options[] is renamed to wal_sync_method_options[].
* assign_xlog_sync_method() is renamed to assign_wal_sync_method().
* The names of the available synchronization methods are now
prefixed with "WAL_SYNC_METHOD_" and have been moved into a
WalSyncMethod enum.
* PLATFORM_DEFAULT_SYNC_METHOD is renamed to
PLATFORM_DEFAULT_WAL_SYNC_METHOD, and DEFAULT_SYNC_METHOD is
renamed to DEFAULT_WAL_SYNC_METHOD.
These more descriptive names help distinguish the code for
wal_sync_method from the code for DataDirSyncMethod (e.g., the
recovery_init_sync_method configuration parameter and the
--sync-method option provided by several frontend utilities). This
change also prevents name collisions between the aforementioned
sets of code. Since this only improves the naming of internal
identifiers, there should be no behavior change.
Author: Maxim Orlov
Discussion: https://postgr.es/m/CACG%3DezbL1gwE7_K7sr9uqaCGkWhmvRTcTEnm3%2BX1xsRNwbXULQ%40mail.gmail.com
When converting a timestamp to/from with/without time zone, the SQL
Standard specifies an AT LOCAL variant of AT TIME ZONE which uses the
session's time zone. This includes three system functions able to do
the work in the same way as the existing flavors for AT TIME ZONE,
except that these need to be marked as stable as they depend on the
session's TimeZone GUC.
Bump catalog version.
Author: Vik Fearing
Reviewed-by: Laurenz Albe, Cary Huang, Michael Paquier
Discussion: https://postgr.es/m/8e25dec4-5667-c1a5-6581-167d710c2182@postgresfriends.org
This adds a new option called BGWORKER_BYPASS_ROLELOGINCHECK to the
flags available to BackgroundWorkerInitializeConnection() and
BackgroundWorkerInitializeConnectionByOid().
This gives the possibility to bgworkers to bypass the role login check,
making possible the use of a role that has no login rights while not
being a superuser. PostgresInit() gains a new flag called
INIT_PG_OVERRIDE_ROLE_LOGIN, taking advantage of the refactoring done in
4800a5dfb4.
Regression tests are added to worker_spi to check the behavior of this
new option with bgworkers.
Author: Bertrand Drouvot
Reviewed-by: Nathan Bossart, Michael Paquier, Bharath Rupireddy
Discussion: https://postgr.es/m/bcc36259-7850-4882-97ef-d6b905d2fc51@gmail.com
InitPostgres() has been using a set of boolean arguments to control its
behavior, and a patch under discussion was aiming at expanding it with a
third one. In preparation for expanding this area, this commit switches
all the current boolean arguments of this routine to a single bits32
argument instead. Two values are currently supported for the flags:
- INIT_PG_LOAD_SESSION_LIBS to load [session|local]_preload_libraries at
startup.
- INIT_PG_OVERRIDE_ALLOW_CONNS to allow connection to a database even if
it has !datallowconn. This is used by bgworkers.
Reviewed-by: Bertrand Drouvot
Discussion: https://postgr.es/m/ZSTn66_BXRZCeaqS@paquier.xyz
The comment claimed that it is "called from postmaster", but it is
actually called in the child process, pretty early in the process
initialization. I guess you could interpret "called from postmaster"
to mean that, but it seems wrong to me. Rename the function to be
consistent with other functions with similar role.
Reviewed-by: Thomas Munro
Discussion: https://www.postgresql.org/message-id/4f95c1fc-ad3c-7974-3a8c-6faa3931804c@iki.fi
Going by c4a1933b4, b33ef397a and 05893712c (to name just a few), it seems
that maintaining debug_print_rel() is often forgotten. In the case of
c4a1933b4, it was several years before anyone noticed that a path type
was not handled by debug_print_rel(). (debug_print_rel() is only
compiled when building with OPTIMIZER_DEBUG).
After a quick survey on the pgsql-hackers mailing list, nobody came
forward to admit that they use OPTIMIZER_DEBUG. So to prevent any future
maintenance neglect, let's just remove debug_print_rel() and have
OPTIMIZER_DEBUG make use of pprint() instead (as suggested by Tom Lane).
If anyone wants to come forward to claim they make use of
OPTIMIZER_DEBUG in a way that they need debug_print_rel() then they have
around 10 months remaining in the v17 cycle where we could revert this.
If nobody comes forward in that time, then we can likely safely declare
debug_print_rel() as not worth keeping.
Discussion: https://postgr.es/m/CAApHDvoCdjo8Cu2zEZF4-AxWG-90S+pYXAnoDDa9J3xH-OrczQ@mail.gmail.com
Back in the 8.3 era we discovered that it was problematic if
libpq.so had encoding ID assignments different from the backend,
which is possible because on some platforms libpq.so might be
of a different major version from the calling programs.
psql should use libpq's assignments, but initdb has to use the
backend's, else it will put wrong values into pg_database.
The solution devised in commit 8468146b0 relied on giving initdb
its own copy of encnames.c rather than relying on the functions
exported by libpq. Later, that metamorphosed into ensuring that
libpgcommon got linked before libpq -- which made things OK for
initdb but broke psql. We didn't notice for lack of any changes
in enum pg_enc since then. Commit 06843df4a reversed that, fixing
the latent bug in psql but adding one in initdb. The meson build
infrastructure is also not being sufficiently careful about link
order, and trying to make it so would be equally fragile.
Hence, let's use a new scheme based on giving the libpq-exported
symbols different real names than the same functions exported from
libpgcommon.a or libpgcommon_srv.a. (We could distinguish those
two cases as well, but there seems no need to.) libpq gets the
official names to avoid an ABI break for libpq clients, while the
other cases use #define's to make the real names "xxx_private"
rather than "xxx". By controlling where the #define's are
applied, we can force any particular client program to use one
set or the other of the encnames.c functions.
We cannot back-patch this, since it'd be an ABI break for backend
loadable modules, but there seems little need to. We're just
trying to ensure that the world is safe for hypothetical future
additions to enum pg_enc.
In passing this should fix "duplicate symbol" linker warnings
that we've been seeing on AIX buildfarm members since commit
06843df4a. It's not very clear why that linker is complaining
now, when there were strictly *more* duplicates visible before,
but in any case this should remove the reason for complaint.
Patch by me; thanks to Andres Freund for review.
Discussion: https://postgr.es/m/2385119.1696354473@sss.pgh.pa.us
Currently, B-tree code matches every scan key to every item on the page.
Imagine the ordered B-tree scan for the query like this.
SELECT * FROM tbl WHERE col > 'a' AND col < 'b' ORDER BY col;
The (col > 'a') scan key will be always matched once we find the location to
start the scan. The (col < 'b') scan key will match every item on the page
as long as it matches the last item on the page.
This patch implements prechecking of the scan keys required for directional
scan on beginning of page scan. If precheck is successful we can skip this
scan keys check for the items on the page. That could lead to significant
acceleration especially if the comparison operator is expensive.
Idea from patch by Konstantin Knizhnik.
Discussion: https://postgr.es/m/079c3f8e-3371-abe2-e93c-fc8a0ae3f571%40garret.ru
Reviewed-by: Peter Geoghegan, Pavel Borisov
BuildDescForRelation() main job is to convert ColumnDef lists to
pg_attribute/tuple descriptor arrays, which is really mostly an
internal subroutine of DefineRelation() and some related functions,
which is more the remit of tablecmds.c and doesn't have much to do
with the basic tuple descriptor interfaces in tupdesc.c. This is also
supported by observing the header includes we can remove in tupdesc.c.
By moving it over, we can also (in the future) make
BuildDescForRelation() use more internals of tablecmds.c that are not
sensible to be exposed in tupdesc.c.
Discussion: https://www.postgresql.org/message-id/flat/52a125e4-ff9a-95f5-9f61-b87cf447e4da@eisentraut.org
Keep track of the used size of the array. That avoids looping through
the whole array in a few places. It doesn't matter from a performance
point of view since the array is small anyway, but this feels less
surprising and is a little less code. Now that we have an explicit
NumListenSockets variable that is statically initialized to 0, we
don't need the loop to initialize the array.
Allocate the array in PostmasterContext. The array isn't needed in
child processes, so this allows reusing that memory. We could easily
make the array resizable now, but we haven't heard any complaints
about the current 64 sockets limit.
Discussion: https://www.postgresql.org/message-id/7bb7ad65-a018-2419-742f-fa5fd877d338@iki.fi
Previously, the JSON code didn't have to worry too much about freeing
JsonLexContext, because it was never too long-lived. With new features
being added for SQL/JSON this is no longer the case. Add a routine
that knows how to free this struct and apply that to a few places, to
prevent this from becoming problematic.
At the same time, we change the API of makeJsonLexContextCstringLen to
make it receive a pointer to JsonLexContext for callers that want it to
be stack-allocated; it can also be passed as NULL to get the original
behavior of a palloc'ed one.
This also causes an ABI break due to the addition of flags to
JsonLexContext, so we can't easily backpatch it. AFAICS that's not much
of a problem; apparently some leaks might exist in JSON usage of
text-search, for example via json_to_tsvector, but I haven't seen any
complaints about that.
Per Coverity complaint about datum_to_jsonb_internal().
Discussion: https://postgr.es/m/20230808174110.oq3iymllsv6amkih@alvherre.pgsql
It is unnecessary to include this field in IndexInfo. It is only used
by DDL code, not during execution. It is really only used to pass
local information around between functions in index.c and indexcmds.c,
for which it is clearer to use local variables, like in similar cases.
Discussion: https://www.postgresql.org/message-id/flat/f84640e3-00d3-5abd-3f41-e6a19d33c40b@eisentraut.org
The retry loop is needed because heap_page_prune() calls
HeapTupleSatisfiesVacuum() and then lazy_scan_prune() does the same
thing again, and they might get different answers due to concurrent
clog updates. But this patch makes heap_page_prune() return the
HeapTupleSatisfiesVacuum() results that it computed back to the
caller, which allows lazy_scan_prune() to avoid needing to recompute
those values in the first place. That's nice both because it eliminates
the need for a retry loop and also because it's cheaper.
Melanie Plageman, reviewed by David Geier, Andres Freund, and me.
Discussion: https://postgr.es/m/CAAKRu_br124qsGJieuYA0nGjywEukhK1dKBfRdby_4yY3E9SXA%40mail.gmail.com
This adjusts the expression evaluation code for CoerceViaIO and
CoerceToDomain to handle errors softly if needed.
For CoerceViaIo, this means using InputFunctionCallSafe(), which
provides the option to handle errors softly, instead of calling the
type input function directly.
For CoerceToDomain, this simply entails replacing the ereport() in
ExecEvalConstraintCheck() by errsave().
In both cases, the ErrorSaveContext to be used when evaluating the
expression is stored by ExecInitExprRec() in the expression's struct
in the expression's ExprEvalStep. The ErrorSaveContext is passed by
setting ExprState.escontext to point to it when calling
ExecInitExprRec() on the expression whose errors are to be handled
softly.
Note that no call site of ExecInitExprRec() has been changed in this
commit, so there's no functional change. This is intended for
implementing new SQL/JSON expression nodes in future commits that
will use to it suppress errors that may occur during type coercions.
Reviewed-by: Álvaro Herrera
Discussion: https://postgr.es/m/CA+HiwqE4XTdfb1nW=Ojoy_tQSRhYt-q_kb6i5d4xcKyrLC1Nbg@mail.gmail.com
These options already exist, but you need to specify a column list for
them, which can be cumbersome. We already have the possibility of all
columns for FORCE QUOTE, so this is simply extending that facility to
FORCE_NULL and FORCE_NOT_NULL.
Author: Zhang Mingli
Reviewed-By: Richard Guo, Kyatoro Horiguchi, Michael Paquier.
Discussion: https://postgr.es/m/CACJufxEnVqzOFtqhexF2+AwOKFrV8zHOY3y=p+gPK6eB14pn_w@mail.gmail.com
Under some circumstances, concurrent MERGE operations could lead to
inconsistent results, that varied according the plan chosen. This was
caused by a lack of rowmarks on the source relation, which meant that
EvalPlanQual rechecking was not guaranteed to return the same source
tuples when re-running the join query.
Fix by ensuring that preprocess_rowmarks() sets up PlanRowMarks for
all non-target relations used in MERGE, in the same way that it does
for UPDATE and DELETE.
Per bug #18103. Back-patch to v15, where MERGE was introduced.
Dean Rasheed, reviewed by Richard Guo.
Discussion: https://postgr.es/m/18103-c4386baab8e355e3%40postgresql.org
nbtree's mark/restore processing failed to correctly handle an edge case
involving array key advancement and related search-type scan key state.
Scans with ScalarArrayScalarArrayOpExpr quals requiring mark/restore
processing (for a merge join) could incorrectly conclude that an
affected array/scan key must not have advanced during the time between
marking and restoring the scan's position.
As a result of all this, array key handling within btrestrpos could skip
a required call to _bt_preprocess_keys(). This confusion allowed later
primitive index scans to overlook tuples matching the true current array
keys. The scan's search-type scan keys would still have spurious values
corresponding to the final array element(s) -- not values matching the
first/now-current array element(s).
To fix, remember that "array key wraparound" has taken place during the
ongoing btrescan in a flag variable stored in the scan's state, and use
that information at the point where btrestrpos decides if another call
to _bt_preprocess_keys is required.
Oversight in commit 70bc5833, which taught nbtree to handle array keys
during mark/restore processing, but missed this subtlety. That commit
was itself a bug fix for an issue in commit 9e8da0f7, which taught
nbtree to handle ScalarArrayOpExpr quals natively.
Author: Peter Geoghegan <pg@bowt.ie>
Discussion: https://postgr.es/m/CAH2-WzkgP3DDRJxw6DgjCxo-cu-DKrvjEv_ArkP2ctBJatDCYg@mail.gmail.com
Backpatch: 11- (all supported branches).
Previously, one of the values in the struct was returned as the return
value, and another was returned via an output parameter. In
preparation for returning more stuff, consolidate both values into a
struct returned via an output parameter.
Melanie Plageman, reviewed by Andres Freund and by me.
Discussion: https://postgr.es/m/CAAKRu_br124qsGJieuYA0nGjywEukhK1dKBfRdby_4yY3E9SXA%40mail.gmail.com
