This adjusts cast functions from jsonb to other types to support soft
errors. This just involves some refactoring of the underlying helper
functions to use ereturn.
This is in preparation for a future feature where conversion errors in
casts can be caught.
Author: jian he <jian.universality@gmail.com>
Reviewed-by: Amul Sul <sulamul@gmail.com>
Reviewed-by: Corey Huinker <corey.huinker@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/CADkLM%3Dfv1JfY4Ufa-jcwwNbjQixNViskQ8jZu3Tz_p656i_4hQ%40mail.gmail.com
When a backend attempts to start a read IO and finds the first buffer already
has I/O in progress, previously it waited for that I/O to complete before
initiating reads for any of the subsequent buffers.
Although it must wait for the I/O to finish when acquiring the buffer, there's
no reason for it to wait when setting up the read operation. Waiting at this
point prevents starting I/O on subsequent buffers and can significantly reduce
concurrency.
This matters in two workloads:
1) When multiple backends scan the same relation concurrently.
2) When a single backend requests the same block multiple times within the
readahead distance.
Waiting each time an in-progress read is encountered effectively degenerates
the access pattern into synchronous I/O.
To fix this, when encountering an already in-progress IO for the head buffer,
the wait reference is now recorded and waiting is deferred until
WaitReadBuffers(), when the buffer actually needs to be acquired.
In rare cases, a backend may still need to wait synchronously at IO
start time: If another backend has set BM_IO_IN_PROGRESS on the buffer
but has not yet set the wait reference. Such windows should be brief and
uncommon.
Author: Melanie Plageman <melanieplageman@gmail.com>
Author: Andres Freund <andres@anarazel.de>
Reviewed-by: Andres Freund <andres@anarazel.de>
Reviewed-by: Melanie Plageman <melanieplageman@gmail.com>
Reviewed-by: Nazir Bilal Yavuz <byavuz81@gmail.com>
Discussion: https://postgr.es/m/flat/zljergweqti7x67lg5ije2rzjusie37nslsnkjkkby4laqqbfw%403p3zu522yykv
Until now StartBufferIO() had a few weaknesses:
- As it did not submit staged IOs, it was not safe to call StartBufferIO()
where there was a potential for unsubmitted IO, which required
AsyncReadBuffers() to use a wrapper (ReadBuffersCanStartIO()) around
StartBufferIO().
- With nowait = true, the boolean return value did not allow to distinguish
between no IO being necessary and having to wait, which would lead
ReadBuffersCanStartIO() to unnecessarily submit staged IO.
- Several callers needed to handle both local and shared buffers, requiring
the caller to differentiate between StartBufferIO() and StartLocalBufferIO()
- In a future commit some callers of StartBufferIO() want the BufferDesc's
io_wref to be returned, to asynchronously wait for in-progress IO
- Indicating whether to wait with the nowait parameter was somewhat confusing
compared to a wait parameter
Address these issues as follows:
- StartBufferIO() is renamed to StartSharedBufferIO()
- A new StartBufferIO() is introduced that supports both shared and local
buffers
- The boolean return value has been replaced with an enum, indicating whether
the IO is already done, already in progress or that the buffer has been
readied for IO
- A new PgAioWaitRef * argument allows the caller to get the wait reference is
desired. All current callers pass NULL, a user of this will be introduced
subsequently
- Instead of the nowait argument there now is wait
This probably would not have been worthwhile on its own, but since all these
lines needed to be touched anyway...
Author: Andres Freund <andres@anarazel.de>
Author: Melanie Plageman <melanieplageman@gmail.com>
Discussion: https://postgr.es/m/zljergweqti7x67lg5ije2rzjusie37nslsnkjkkby4laqqbfw@3p3zu522yykv
PostmasterContext is not available in single-user mode, use
TopMemoryContext instead. Also make sure that we use the correct
memory context in the lappend().
Author: Nathan Bossart <nathandbossart@gmail.com>
Discussion: https://www.postgresql.org/message-id/acb_Eo1XtmCO_9z7@nathan
Now that the buffer content lock is implemented as part of BufferDesc.state,
releasing the lock and unpinning the buffer can be implemented as a single
atomic operation.
This improves workloads that have heavy contention on a small number of
buffers substantially, I e.g., see a ~20% improvement for pipelined readonly
pgbench on an older two socket machine.
Reviewed-by: Melanie Plageman <melanieplageman@gmail.com>
Discussion: https://postgr.es/m/5ubipyssiju5twkb7zgqwdr7q2vhpkpmuelxfpanetlk6ofnop@hvxb4g2amb2d
An upcoming commit will make UnlockReleaseBuffer() considerably faster and
more scalable than doing LockBuffer(BUFFER_LOCK_UNLOCK); ReleaseBuffer();. But
it's a small performance benefit even as-is.
Most of the callsites changed in this patch are not performance sensitive,
however some, like the nbtree ones, are in critical paths.
This patch changes all the easily convertible places over to
UnlockReleaseBuffer() mainly because I needed to check all of them anyway, and
reducing cases where the operations are done separately makes the checking
easier.
Reviewed-by: Melanie Plageman <melanieplageman@gmail.com>
Discussion: https://postgr.es/m/5ubipyssiju5twkb7zgqwdr7q2vhpkpmuelxfpanetlk6ofnop@hvxb4g2amb2d
After the series of preceding commits introducing and using
BufferBeginSetHintBits()/BufferSetHintBits16(), hint bits are not set anymore
while IO is going on. Therefore we do not need to copy pages while they are
being written out anymore.
For the same reason XLogSaveBufferForHint() now does not need to operate on a
copy of the page anymore, but can instead use the normal XLogRegisterBuffer()
mechanism. For that the assertions and comments to XLogRegisterBuffer() had to
be updated to allow share-exclusive locked buffers to be registered.
Reviewed-by: Melanie Plageman <melanieplageman@gmail.com>
Discussion: https://postgr.es/m/5ubipyssiju5twkb7zgqwdr7q2vhpkpmuelxfpanetlk6ofnop@hvxb4g2amb2d
Autovacuum workers scan pg_class twice to collect the set of tables
to process. The first pass is for plain relations and materialized
views, and the second is for TOAST tables. When the worker finds a
table to process, it adds it to the end of a list. Later on, it
processes the tables in the same order as the list. This simple
strategy has worked surprisingly well for a long time, but there
have been many discussions over the years about trying to improve
it.
This commit introduces a scoring system that is used to sort the
aforementioned list of tables to process. The idea is to have
autovacuum workers prioritize tables that are furthest beyond their
thresholds (e.g., a table nearing transaction ID wraparound should
be vacuumed first). This prioritization scheme is certainly far
from perfect; there are simply too many possibilities for any
scoring technique to work across all workloads, and the situation
might change significantly between the time we calculate the score
and the time that autovacuum processes it. However, we have
attemped to develop something that is expected to work for a large
portion of workloads with reasonable parameter settings.
The score is calculated as the maximum of the ratios of each of the
table's relevant values to its threshold. For example, if the
number of inserted tuples is 100, and the insert threshold for the
table is 80, the insert score is 1.25. If all other scores are
below that value, the table's score will be 1.25. The other
criteria considered for the score are the table ages (both
relfrozenxid and relminmxid) compared to the corresponding
freeze-max-age setting, the number of update/deleted tuples
compared to the vacuum threshold, and the number of
inserted/updated/deleted tuples compared to the analyze threshold.
Once exception to the previous paragraph is for tables nearing
wraparound, i.e., those that have surpassed the effective failsafe
ages. In that case, the relfrozenxid/relminmxid-based score is
scaled aggressively so that the table has a decent chance of
sorting to the front of the list.
To adjust how strongly each component contributes to the score, the
following parameters can be adjusted from their default of 1.0 to
anywhere between 0.0 and 10.0 (inclusive). Setting all of these to
0.0 restores pre-v19 prioritization behavior:
autovacuum_freeze_score_weight
autovacuum_multixact_freeze_score_weight
autovacuum_vacuum_score_weight
autovacuum_vacuum_insert_score_weight
autovacuum_analyze_score_weight
This is intended to be a baby step towards smarter autovacuum
workers. Possible future improvements include, but are not limited
to, periodic reprioritization, automatic cost limit adjustments,
and better observability (e.g., a system view that shows current
scores). While we do not expect this commit to produce any
earth-shattering improvements, it is arguably a prerequisite for
the aforementioned follow-up changes.
Reviewed-by: Sami Imseih <samimseih@gmail.com>
Reviewed-by: David Rowley <dgrowleyml@gmail.com>
Reviewed-by: Robert Haas <robertmhaas@gmail.com>
Reviewed-by: wenhui qiu <qiuwenhuifx@gmail.com>
Reviewed-by: Greg Burd <greg@burd.me>
Reviewed-by: Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>
Discussion: https://postgr.es/m/aOaAuXREwnPZVISO%40nathan
The PredicateLockShmemInit function is pretty complicated, and one
source of confusion is that it reuses the same local variable for
sizes of things. Replace the different uses with separate variables
for clarity.
Reviewed-by: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>
Discussion: https://www.postgresql.org/message-id/113724ab-0028-493f-9605-6e8570f0939f@iki.fi
An element pattern variable may be repeated in the path pattern.
GraphTableParseState maintains a list of all variable names used in
the graph pattern. Add a new variable name to that list only when it
is not present already. This isn't a problem right now, but it could
be in the future.
Author: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>
Discussion: https://www.postgresql.org/message-id/CAExHW5tR4O0vjeqTCPr2VB5pYjNYbJgbCBEQf63NtU5Pz1MiOQ%40mail.gmail.com
Adding an implicit empty vertex pattern when a path pattern starts or
ends with an edge pattern or when two consecutive edge patterns appear
in the pattern is not supported right now. Prohibit such path
patterns.
Author: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>
Reported-by: Alexander Lakhin <exclusion@gmail.com>
Reviewed-by: Henson Choi <assam258@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/72a23702-6d96-4103-a54b-057c2352e885%2540eisentraut.org
Previously we reused the shmem allocator's ShmemLock to also protect
lwlock.c's shared memory structures. Introduce a separate spinlock for
lwlock.c for the sake of modularity. Now that lwlock.c has its own
shared memory struct (LWLockTranches), this is easy to do.
Reviewed-by: Nathan Bossart <nathandbossart@gmail.com>
Discussion: https://www.postgresql.org/message-id/47aaf57e-1b7b-4e12-bda2-0316081ff50e@iki.fi
Merge the LWLockTranches and NamedLWLockTrancheRequest data structures
in shared memory into one array of user-defined tranches. The
NamedLWLockTrancheRequest list is now only used in postmaster, to hold
the requests until shared memory is initialized.
Introduce a C struct, LWLockTranches, to hold all the different fields
kept in shared memory. This gives an easier overview of what are all
the things kept in shared memory. Previously, we had separate pointers
for LWLockTrancheNames, LWLockCounter and the (shared memory copy of)
NamedLWLockTrancheRequestArray.
Reviewed-by: Nathan Bossart <nathandbossart@gmail.com>
Discussion: https://www.postgresql.org/message-id/47aaf57e-1b7b-4e12-bda2-0316081ff50e@iki.fi
The "named tranches" term is a little confusing. In most places it
refers to tranches requested with RequestNamedLWLockTranche(), even
though all built-in tranches and tranches allocated with
LWLockNewTrancheId() also have a name. But in MAX_NAMED_TRANCHES, it
refers to tranches requested with either RequestNamedLWLockTranche()
or LWLockNewTrancheId(), as it's the maximum of all of those in total.
The "user defined" term is already used in
LWTRANCHE_FIRST_USER_DEFINED, so let's standardize on that to mean
tranches allocated with either RequestNamedLWLockTranche() or
LWLockNewTrancheId().
Reviewed-by: Nathan Bossart <nathandbossart@gmail.com>
Reviewed-by: Sami Imseih <samimseih@gmail.com>
Discussion: https://www.postgresql.org/message-id/47aaf57e-1b7b-4e12-bda2-0316081ff50e@iki.fi
Typically, we have only one PlannerInfo for any given subquery, but
when we are considering a MinMaxAggPath or a hashed subplan, we end
up creating a second PlannerInfo for the same portion of the query,
with a clone of the original range table. In fact, in the MinMaxAggPath
case, we might end up creating several clones, one per aggregate.
At present, there's no easy way for a plugin, such as pg_plan_advice,
to understand the relationships between the original range table and
the copies of it that are created in these cases. To fix, add an
alternative_plan_name field to PlannerInfo. For a hashed subplan, this
is the plan name for the non-hashed alternative; for minmax aggregates,
this is the plan_name from the parent PlannerInfo; otherwise, it's the
same as plan_name.
Discussion: http://postgr.es/m/CA+TgmoYuWmN-00Ec5pY7zAcpSFQUQLbgAdVWGR9kOR-HM-fHrA@mail.gmail.com
Reviewed-by: Lukas Fittl <lukas@fittl.com>
Restructure AsyncReadBuffers() to use early return when the head buffer is
already valid, instead of using a did_start_io flag and if/else branches. Also
move around a bit of the code to be located closer to where it is used. This
is a refactor only.
Author: Melanie Plageman <melanieplageman@gmail.com>
Reviewed-by: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/zljergweqti7x67lg5ije2rzjusie37nslsnkjkkby4laqqbfw@3p3zu522yykv
Already two places count buffer hits, requiring quite a few lines of
code since we do accounting in so many places. Future commits will add
more locations, so refactor into a helper.
Author: Melanie Plageman <melanieplageman@gmail.com>
Reviewed-by: Nazir Bilal Yavuz <byavuz81@gmail.com>
Discussion: https://postgr.es/m/zljergweqti7x67lg5ije2rzjusie37nslsnkjkkby4laqqbfw@3p3zu522yykv
PinBufferForBlock() is always_inline and called in a loop in
StartReadBuffersImpl(). Previously it computed io_context and io_object
internally, which required calling IOContextForStrategy() -- a non-inline
function the compiler cannot prove is side-effect-free. This could potential
cause unneeded redundant function calls.
Compute io_context and io_object in the callers instead, allowing
StartReadBuffersImpl() to do so once before entering the loop.
Author: Melanie Plageman <melanieplageman@gmail.com>
Suggested-by: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/zljergweqti7x67lg5ije2rzjusie37nslsnkjkkby4laqqbfw@3p3zu522yykv
AsyncReadBuffer()'s no-IO needed path passed
TRACE_POSTGRESQL_BUFFER_READ_DONE the wrong block number because it had
already incremented operation->nblocks_done. Fix by folding the
nblocks_done offset into the blocknum local variable at initialization.
Author: Melanie Plageman <melanieplageman@gmail.com>
Reviewed-by: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/u73un3xeljr4fiidzwi4ikcr6vm7oqugn4fo5vqpstjio6anl2%40hph6fvdiiria
Backpatch-through: 18
When my commit e222534679 added the
concept of disabled_nodes, it failed to add a disabled_nodes field
to SubPlan. This is a regression: before that commit, when
fix_alternative_subplan compared the costs of two plans, the number
of disabled nodes affected the result, because it was just a
component of the total cost. After that commit, it no longer did,
making it possible for a disabled path to win on cost over one that
is not disabled. Fix that.
As usual for planner fixes that might destabilize plan choices,
no back-patch.
Discussion: https://postgr.es/m/CA+TgmoaK=4w7-qknUo3QhUJ53pXZq=c=KgZmRyD+k7ytqfmgSg@mail.gmail.com
Reviewed-by: Lukas Fittl <lukas@fittl.com>
This dials back a couple of the qualifiers added by commit
7724cb9935. Specifically, in match_boolean_partition_clause() the
call to negate_clause() casts away the const, so we shouldn't make the
input argument const.
Previously, when the startup process applied WAL and requested walreceiver
to send an apply notification to the primary, walreceiver sent a status reply
unconditionally, even if the WAL locations had not advanced since
the previous update.
As a result, the standby could send two consecutive status reply messages
with identical WAL locations even though wal_receiver_status_interval had
not yet elapsed. This could unexpectedly reset the reported replication lag,
making it difficult for users to monitor lag. The second message was also
unnecessary because it reported no progress.
This commit updates walreceiver to send a reply only when the apply location
has advanced since the last status update, even when the startup process
requests a notification.
Author: Fujii Masao <masao.fujii@gmail.com>
Reviewed-by: Shinya Kato <shinya11.kato@gmail.com>
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Discussion: https://postgr.es/m/CAOzEurTzcUrEzrH97DD7+Yz=HGPU81kzWQonKZvqBwYhx2G9_A@mail.gmail.com
pg_stat_replication is documented to keep the last measured lag values for
a short time after the standby catches up, and then set them to NULL when
there is no WAL activity. However, previously lag values could become NULL
prematurely even while WAL activity was ongoing, especially in logical
replication.
This happened because the code cleared lag when two consecutive reply messages
indicated that the apply location had caught up with the send location.
It did not verify that the reported positions were unchanged, so lag could be
cleared even when positions had advanced between messages. In logical
replication, where the apply location often quickly catches up, this issue was
more likely to occur.
This commit fixes the issue by clearing lag only when the standby reports that
it has fully replayed WAL (i.e., both flush and apply locations have caught up
with the send location) and the write/flush/apply positions remain unchanged
across two consecutive reply messages.
The second message with unchanged positions typically results from
wal_receiver_status_interval, so lag values are cleared after that interval
when there is no activity. This avoids showing stale lag data while preventing
premature NULL values.
Even with this fix, lag may rarely become NULL during activity if identical
position reports are sent repeatedly. Eliminating such duplicate messages
would address this fully, but that change is considered too invasive for stable
branches and will be handled in master only later.
Backpatch to all supported branches.
Author: Shinya Kato <shinya11.kato@gmail.com>
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Reviewed-by: Fujii Masao <masao.fujii@gmail.com>
Discussion: https://postgr.es/m/CAOzEurTzcUrEzrH97DD7+Yz=HGPU81kzWQonKZvqBwYhx2G9_A@mail.gmail.com
Backpatch-through: 14
Reorder the validation checks in replorigin_session_setup() to provide a
more logical flow. This makes the function easier to follow and ensures
that basic state checks are performed consistently.
Additionally, update an error message to align its phrasing with similar
diagnostics in the replication origin subsystem, improving overall
consistency.
Author: Heikki Linnakangas <hlinnaka@iki.fi>
Reviewed-by: shveta malik <shveta.malik@gmail.com>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Discussion: https://postgr.es/m/e0508305-bc6a-417c-b969-36564d632f9e@iki.fi
Previously, pg_promote() looped a fixed number of times, calculated from
the specified timeout, and waited 100ms on a latch, once per iteration,
for the promotion of a standby to complete. However, unrelated signals
to the backend could set the latch and wake up the backend early,
resulting in a faster consumption of the loops and an execution time of
the function that does not match with the timeout input given in input.
This could be confusing for the function caller, especially if some
backend-side timeout is aggressive, because the function would return
much earlier than expected and report that the promote request has not
completed within the time requested.
This commit refines the logic to track the time actually elapsed, by
looping until the requested duration has truly passed. The code
calculates the end time we expect, then uses it when looping.
Author: Robert Pang <robertpang@google.com>
Reviewed-by: Tiancheng Ge <getiancheng_2012@163.com>
Discussion: https://postgr.es/m/CAJhEC07OK8J7tLUbyiccnuOXRE7UKxBNqD2-pLfeFXa=tBoWtw@mail.gmail.com
This adds support for base32hex encoding and decoding, as defined in
RFC 4648 Section 7. Unlike standard base32, base32hex uses the
extended hex alphabet (0-9, A-V) which preserves the lexicographical
order of the encoded data.
This is particularly useful for representing UUIDv7 values in a
compact string format while maintaining their time-ordered sort
property.
The encode() function produces output padded with '=', while decode()
accepts both padded and unpadded input. Following the behavior of
other encoding types, decoding is case-insensitive.
Suggested-by: Sergey Prokhorenko <sergeyprokhorenko@yahoo.com.au>
Author: Andrey Borodin <x4mmm@yandex-team.ru>
Co-authored-by: Aleksander Alekseev <aleksander@tigerdata.com>
Reviewed-by: Masahiko Sawada <sawada.mshk@gmail.com>
Reviewed-by: Илья Чердаков <i.cherdakov.pg@gmail.com>
Reviewed-by: Chengxi Sun <chengxisun92@gmail.com>
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Discussion: https://postgr.es/m/CAJ7c6TOramr1UTLcyB128LWMqita1Y7%3Darq3KHaU%3Dqikf5yKOQ%40mail.gmail.com
This is similar to the standard behavior in GCC. For MSVC, we set all
headers in angle brackets to be considered system headers. (GCC goes
by path, not include style.)
The required option is available since VS 2017. (Before VS 2019
version 16.10, the additional option /experimental:external is
required, but per discussion in [0], we effectively require 16.11, so
this shouldn't be a problem.)
[0]: https://www.postgresql.org/message-id/04ab76a3-186c-4a37-8076-e6882ebf9d43%40eisentraut.org
Then, we can remove one workaround for avoiding a warning from a
system header. (And some warnings to be enabled in the future could
benefit from this.)
Reviewed-by: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/aa73q1aT0A3/vke/%40ip-10-97-1-34.eu-west-3.compute.internal
Constructing a Subcription object uses a number of small or temporary
allocations. Use a per-object memory context for easy cleanup.
Get rid of FreeSubscription() which did not free all the allocations
anyway. Also get rid of the PG_TRY()/PG_CATCH() logic in
ForeignServerConnectionString() which were used to avoid leaks during
GetSubscription().
Co-authored-by: Álvaro Herrera <alvherre@kurilemu.de>
Suggested-by: Andres Freund <andres@anarazel.de>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Discussion: https://postgr.es/m/xvdjrdqnpap3uq7owbaox3r7p5gf7sv62aaqf2ju3vb6yglatr%40kvvwhoudrlxq
Discussion: https://postgr.es/m/CAA4eK1K=WjZ1maBCmj=5ZdO66AwPORK5ZBxVKedS0xdCcb621A@mail.gmail.com
There are no remaining users that emit XLOG_HEAP2_VISIBLE records, so it
can be removed. This includes deleting the xl_heap_visible struct and
all functions responsible for emitting or replaying XLOG_HEAP2_VISIBLE
records.
Bumps XLOG_PAGE_MAGIC because we removed a WAL record type.
Author: Melanie Plageman <melanieplageman@gmail.com>
Reviewed-by: Andrey Borodin <x4mmm@yandex-team.ru>
Reviewed-by: Andres Freund <andres@anarazel.de>
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Discussion: https://postgr.es/m/flat/CAAKRu_ZMw6Npd_qm2KM%2BFwQ3cMOMx1Dh3VMhp8-V7SOLxdK9-g%40mail.gmail.com
As part of removing XLOG_HEAP2_VISIBLE records, phase I of VACUUM now
marks empty pages all-visible and all-frozen in a
XLOG_HEAP2_PRUNE_VACUUM_SCAN record.
This has no real independent benefit, but empty pages were the last user
of XLOG_HEAP2_VISIBLE, so by making this change we can next remove all
of the XLOG_HEAP2_VISIBLE code.
Author: Melanie Plageman <melanieplageman@gmail.com>
Reviewed-by: Andres Freund <andres@anarazel.de>
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Reviewed-by: Kirill Reshke <reshkekirill@gmail.com>
Earlier version Reviewed-by: Robert Haas <robertmhaas@gmail.com>
Vacuum no longer emits a separate WAL record for each page set
all-visible or all-frozen during phase I. Instead, visibility map
updates are now included in the XLOG_HEAP2_PRUNE_VACUUM_SCAN record that
is already emitted for pruning and freezing.
Previously, heap_page_prune_and_freeze() determined whether a page was
all-visible, but the corresponding VM bits were only set later in
lazy_scan_prune(). Now the VM is updated immediately in
heap_page_prune_and_freeze(), at the same time as the heap
modifications. This reduces WAL volume produced by vacuum.
For now, vacuum is still the only user of heap_page_prune_and_freeze()
allowed to set the VM. On-access pruning is not yet able to set the VM.
Author: Melanie Plageman <melanieplageman@gmail.com>
Reviewed-by: Andres Freund <andres@anarazel.de>
Reviewed-by: Kirill Reshke <reshkekirill@gmail.com>
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Earlier version Reviewed-by: Robert Haas <robertmhaas@gmail.com>
Discussion: https://postgr.es/m/flat/CAAKRu_ZMw6Npd_qm2KM%2BFwQ3cMOMx1Dh3VMhp8-V7SOLxdK9-g%40mail.gmail.com
This function exits early in the case where the number of inner rows
is estimated to be less than 2, on the theory that in that case a
Nested Loop with inner Memoize must lose to a plain Nested Loop.
But since commit 4020b370f2 it's
possible for a plain Nested Loop to be disabled, while a Nested Loop
with inner Memoize is still enabled. In that case, this reasoning
is not valid, so adjust the code not to exit early in that case.
This issue was revealed by a test_plan_advice failure on buildfarm
member skink, where NESTED_LOOP_MEMOIZE() couldn't be enforced on
replanning due to this early exit.
Discussion: http://postgr.es/m/CA+TgmoZUN8FT1Ah=m6Uis5bHa4FUa+_hMDWtcABG17toEfpiUg@mail.gmail.com
During pruning, we keep track of the newest xmin of live tuples on the
page visible to all running and future transactions so that we can use
it later as the snapshot conflict horizon when setting the VM if the
page turns out to be all-visible.
Previously, we stopped updating this value once we determined the page
was not all-visible. However, maintaining it even when the page is not
all-visible is inexpensive and makes the snapshot conflict horizon
calculation clearer. This guarantees it won't contain a stale value.
Since we'll keep it up to date all the time now anyway, there's no
reason not to maintain set_all_visible for on-access pruning. This will
allow us to set the VM on-access in the future.
Author: Melanie Plageman <melanieplageman@gmail.com>
Reviewed-by: Andres Freund <andres@anarazel.de>
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Discussion: https://postgr.es/m/bqc4kh5midfn44gnjiqez3bjqv4zogydguvdn446riw45jcf3y%404ez66il7ebvk
During vacuum's first and third phases, we examine tuples' visibility to
determine if we can set the page all-visible in the visibility map.
Previously, this check compared tuple xmins against a single XID chosen
at the start of vacuum (OldestXmin). We now use GlobalVisState, which
enables future work to set the VM during on-access pruning, since
ordinary queries have access to GlobalVisState but not OldestXmin.
This also benefits vacuum: in some cases, GlobalVisState may advance
during a vacuum, allowing more pages to become considered all-visible.
And, in the future, we could easily add a heuristic to update
GlobalVisState more frequently during vacuums of large tables.
OldestXmin is still used for freezing and as a backstop to ensure we
don't freeze a dead tuple that wasn't yet prunable according to
GlobalVisState in the rare occurrences where GlobalVisState moves
backwards.
Because comparing a transaction ID against GlobalVisState is more
expensive than comparing against a single XID, we defer this check until
after scanning all tuples on the page. Therefore, we perform the
GlobalVisState check only once per page. This is safe because
visibility_cutoff_xid records the newest live xmin on the page; if it is
globally visible, then the entire page is all-visible.
Using GlobalVisState means on-access pruning can also maintain
visibility_cutoff_xid, which is required to set the visibility map
on-access in the future.
Author: Melanie Plageman <melanieplageman@gmail.com>
Reviewed-by: Andres Freund <andres@anarazel.de>
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Reviewed-by: Kirill Reshke <reshkekirill@gmail.com>
Discussion: https://postgr.es/m/flat/bqc4kh5midfn44gnjiqez3bjqv4zogydguvdn446riw45jcf3y%404ez66il7ebvk#c755ef151507aba58471ffaca607e493
The number of .c files that must include access/clog.h can currently be
counted on one's fingers and miss only one (assuming one has the usual
number of hands). However, due to indirect inclusion via proc.h,
there's a lot of files that are pointlessly including it. This is easy
to avoid with the easy trick implemented by this commit.
Author: Álvaro Herrera <alvherre@kurilemu.de>
Discussion: https://postgr.es/m/202603221856.iwlhitt6dxxx@alvherre.pgsql
Since storage/locktags.h was added by commit 322bab7974, many headers
can be made leaner by depending on that instead of on storage/lock.h,
which has many other dependencies.
(In fact, some of these changes were possible even before that.)
Author: Álvaro Herrera <alvherre@kurilemu.de>
Reviewed-by: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Discussion: https://postgr.es/m/abvrRZo52Yx9ZzWQ@ip-10-97-1-34.eu-west-3.compute.internal
check_backtrace_functions() and check_archive_directory() were doing an
empty-string check this way:
*newval[0] == '\0'
which, because of operator precedence, is interpreted as *(newval[0])
instead of (*newval)[0] -- but these variables are pointers to C-strings
and we want to check the first character therein, rather than check the
first pointer of the array, so that interpretation is wrong. This would
be wrong for any index element other than 0, as evidenced by every other
dereference of the same variable in check_backtrace_functions, which use
parentheses.
Add parentheses to make the intended dereference explicit.
This is just cosmetic at this stage, so no backpatch, although it's been
"wrong" for a long time.
Author: Zhang Hu <kongbaik228@gmail.com>
Reviewed-by: Junwang Zhao <zhjwpku@gmail.com>
Reviewed-by: Chao Li <lic@highgo.com>
Discussion: https://postgr.es/m/CAB5m2QssN6UO+ckr6ZCcV0A71mKUB6WdiTw1nHo43v4DTW1Dfg@mail.gmail.com
Previously, XLogFindNextRecord() did not return detailed error information
when it failed to find a valid WAL record. As a result, callers such as
the WAL summarizer, pg_waldump, and pg_walinspect could only report generic
errors (e.g., "could not find a valid record after ..."), making
troubleshooting difficult.
This commit fix the issue by extending XLogFindNextRecord() to return
detailed error information on failure, and updating its callers to include
those details in their error messages.
For example, when pg_waldump is run on a WAL file with an invalid magic number,
it now reports not only the generic error but also the specific cause
(e.g., "invalid magic number").
Author: Anthonin Bonnefoy <anthonin.bonnefoy@datadoghq.com>
Reviewed-by: Mircea Cadariu <cadariu.mircea@gmail.com>
Reviewed-by: Japin Li <japinli@hotmail.com>
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Reviewed-by: Fujii Masao <masao.fujii@gmail.com>
Discussion: https://postgr.es/m/CAO6_XqoxJXddcT4wkd9Xd+cD6Sz-fyspRGuV4Bq-wbXG4pVNzA@mail.gmail.com
The second argument to TupleDescAttr should always be at least zero
and less than natts; otherwise, we index outside of the attribute
array. Assert that this is the case.
Various violations, or possible violations, of this rule that are
currently in the tree are actually harmless, because while
we do call TupleDescAttr() before verifying that the argument is
within range, we don't actually dereference it unless the argument
was within range all along. Nonetheless, the Assert means we
should be more careful, so tidy up accordingly.
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: http://postgr.es/m/CA+TgmoacixUZVvi00hOjk_d9B4iYKswWP1gNqQ8Vfray-AcOCA@mail.gmail.com
This adjusts many C functions underlying casts to support soft errors.
This is in preparation for a future feature where conversion errors in
casts can be caught.
This patch covers cast functions that can be adjusted easily by
changing ereport to ereturn or making other light changes. The
underlying helper functions were already changed to support soft
errors some time ago as part of soft error support in type input
functions.
Other casts and types will require some more work and are being kept
as separate patches.
Author: jian he <jian.universality@gmail.com>
Reviewed-by: Amul Sul <sulamul@gmail.com>
Reviewed-by: Corey Huinker <corey.huinker@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/CADkLM%3Dfv1JfY4Ufa-jcwwNbjQixNViskQ8jZu3Tz_p656i_4hQ%40mail.gmail.com
Both of the checks in DefineIndex() that can produce this error
message have a guard against negative attribute numbers, but lack a
guard to ensure that attno is non-zero. As a result, we can index
off the beginning of the TupleDesc and read a garbage byte for
attgenerated. If that byte happens to be 'v', we'll incorrectly
produce the error mentioned above.
The first call site is easy to hit: any attempt to create an
expression index does so. The second one is not currently hit in
the regression tests, but can be hit by something like
CREATE INDEX ON some_table ((some_function(some_table))).
Found by study of a test_plan_advice failure on buildfarm member
skink, though this issue has nothing to do with test_plan_advice
and seems to have only been revealed by happenstance.
Backpatch-through: 18
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: http://postgr.es/m/CA+TgmoacixUZVvi00hOjk_d9B4iYKswWP1gNqQ8Vfray-AcOCA@mail.gmail.com
The updated comment explains why we use ChangeVarNodes_walker() instead of
expression_tree_walker(), and provides a bit more detail about the differences
in processing top-level Query and subqueries.
Author: Alexander Korotkov <aekorotkov@gmail.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/CAPpHfdvbjq342WTQ705Wmqhe8794pcp7wospz%2BWUJ2qB7vuOqA%40mail.gmail.com
Backpatch-through: 18
