It's now possible to specify a table access method via
CREATE TABLE ... USING for a partitioned table, as well change it with
ALTER TABLE ... SET ACCESS METHOD. Specifying an AM for a partitioned
table lets the value be used for all future partitions created under it,
closely mirroring the behavior of the TABLESPACE option for partitioned
tables. Existing partitions are not modified.
For a partitioned table with no AM specified, any new partitions are
created with the default_table_access_method.
Also add ALTER TABLE ... SET ACCESS METHOD DEFAULT, which reverts to the
original state of using the default for new partitions.
The relcache of partitioned tables is not changed: rd_tableam is not
set, even if a partitioned table has a relam set.
Author: Justin Pryzby <pryzby@telsasoft.com>
Author: Soumyadeep Chakraborty <soumyadeep2007@gmail.com>
Author: Michaël Paquier <michael@paquier.xyz>
Reviewed-by: The authors themselves
Discussion: https://postgr.es/m/CAE-ML+9zM4wJCGCBGv01k96qQ3gFv4WFcFy=zqPHKeaEFwwv6A@mail.gmail.com
Discussion: https://postgr.es/m/20210308010707.GA29832%40telsasoft.com
Up to now, all of the "catcache list" objects within a catalog cache
were just chained together on a single dlist, requiring O(N) time to
search. Remarkably, we've not had serious performance problems with
that so far; but we got a complaint of a bad performance regression
from v15 in a case with a large number of roles in the system, which
traced down to O(N^2) total time when we probed N catcache lists.
Replace that data structure with a hashtable having an enlargeable
number of dlists, in an exactly parallel way to the data structure
we've used for years for the plain CatCTup cache members. The extra
cost of maintaining a hash table seems negligible, since we were
already computing a hash value for list searches.
Normally this'd be HEAD-only material, but in view of the performance
regression it seems advisable to back-patch into v16. In the v16
version of the patch, leave the dead cc_lists field where it is and
add the new fields at the end of struct catcache, to avoid possible
ABI breakage in case any external code is looking at these structs.
(We assume no external code is actually allocating new catcache
structs.)
Per report from alex work.
Discussion: https://postgr.es/m/CAGvXd3OSMbJQwOSc-Tq-Ro1CAz=vggErdSG7pv2s6vmmTOLJSg@mail.gmail.com
The new table AM method free_rd_amcache is responsible for freeing all the
memory related to rd_amcache and setting free_rd_amcache to NULL. If the new
method is not specified, we still assume rd_amcache to be a single chunk of
memory, which could be just pfree'd.
Discussion: https://postgr.es/m/CAPpHfdurb9ycV8udYqM%3Do0sPS66PJ4RCBM1g-bBpvzUfogY0EA%40mail.gmail.com
Reviewed-by: Matthias van de Meent, Mark Dilger, Pavel Borisov
Reviewed-by: Nikita Malakhov, Japin Li
This introduces a new function equalRowTypes() that is effectively a
subset of equalTupleDescs() but only compares the number of attributes
and attribute name, type, typmod, and collation. This is enough for
most existing uses of equalTupleDescs(), which are changed to use the
new function. The only remaining callers of equalTupleDescs() are
those that really want to check the full tuple descriptor as such,
without concern about record or row or record type semantics.
The existing function hashTupleDesc() is renamed to hashRowType(),
because it now corresponds more to equalRowTypes().
The purpose of this change is to be clearer about the semantics of the
equality asked for by each caller. (At least one caller had a comment
that questioned whether equalTupleDescs() was too restrictive.) For
example, 4f622503d6 removed attstattarget from the tuple descriptor
structure. It was not fully clear at the time how this should affect
equalTupleDescs(). Now the answer is clear: By their own definitions,
equalRowTypes() does not care, and equalTupleDescs() just compares
whatever is in the tuple descriptor but does not care why it is in
there.
Reviewed-by: Tomas Vondra <tomas.vondra@enterprisedb.com>
Discussion: https://www.postgresql.org/message-id/flat/f656d6d9-6660-4518-a006-2f65cafbebd1%40eisentraut.org
With commit 21d9c3ee4e, SMgrRelations remain valid until end of
transaction (or longer if they're "pinned"). Relcache invalidation can
happen in the middle of a transaction, so we must not destroy them at
relcache invalidation anymore.
This was revealed by failures in the 'constraints' test in buildfarm
animals using -DCLOBBER_CACHE_ALWAYS. That started failing with commit
8af2565248, which was the first commit that started to rely on an
SMgrRelation living until end of transaction.
Diagnosed-by: Tomas Vondra, Thomas Munro
Reviewed-by: Thomas Munro
Discussion: https://www.postgresql.org/message-id/CA%2BhUKGK%2B5DOmLaBp3Z7C4S-Yv6yoROvr1UncjH2S1ZbPT8D%2BZg%40mail.gmail.com
... and in particular don't return them as replica identity.
The motivation for this change is letting the primary keys be seen by
code that derives NOT NULL constraints from them, when creating
inheritance children; before this change, if you had a deferrable PK,
pg_dump would not recreate the attnotnull marking properly, because the
column would not be considered as having anything to back said marking
after dropping the throwaway NOT NULL constraint.
The reason we don't want these PKs as replica identities is that
replication can corrupt data, if the uniqueness constraint is
transiently broken.
Reported-by: Amul Sul <sulamul@gmail.com>
Reviewed-by: Dean Rasheed <dean.a.rasheed@gmail.com>
Discussion: https://postgr.es/m/CAAJ_b94QonkgsbDXofakHDnORQNgafd1y3Oa5QXfpQNJyXyQ7A@mail.gmail.com
This reverts commit eae7be600b, following a discussion with Tom Lane,
due to concerns that this impacts the decisions made by the planner for
the number of workers spawned based on the inlining and const-folding of
index expressions and predicate for cases that would have worked until
this commit.
Discussion: https://postgr.es/m/162802.1709746091@sss.pgh.pa.us
Backpatch-through: 12
As coded, the planner logic that calculates the number of parallel
workers to use for a parallel index build uses expressions and
predicates from the relcache, which are flattened for the planner by
eval_const_expressions().
As reported in the bug, an immutable parallel-unsafe function flattened
in the relcache would become a Const, which would be considered as
parallel-safe, even if the predicate or the expressions including the
function are not safe in parallel workers. Depending on the expressions
or predicate used, this could cause the parallel build to fail.
Tests are included that check parallel index builds with parallel-unsafe
predicate and expressions. Two routines are added to lsyscache.h to be
able to retrieve expressions and predicate of an index from its pg_index
data.
Reported-by: Alexander Lakhin
Author: Tender Wang
Reviewed-by: Jian He, Michael Paquier
Discussion: https://postgr.es/m/CAHewXN=UaAaNn9ruHDH3Os8kxLVmtWqbssnf=dZN_s9=evHUFA@mail.gmail.com
Backpatch-through: 12
pg_constraint.conwithoutoverlaps was recently added to support primary
keys and unique constraints with the WITHOUT OVERLAPS clause. An
upcoming patch provides the foreign-key side of this functionality,
but the syntax there is different and uses the keyword PERIOD. It
would make sense to use the same pg_constraint field for both of
these, but then we should pick a more general name that conveys "this
constraint has a temporal/period-related feature". conperiod works
for that and is nicely compact. Changing this now avoids possibly
having to introduce versioning into clients. Note there are still
some "without overlaps" variables left, which deal specifically with
the parsing of the primary key/unique constraint feature.
Author: Paul A. Jungwirth <pj@illuminatedcomputing.com>
Discussion: https://www.postgresql.org/message-id/flat/CA+renyUApHgSZF9-nd-a0+OPGharLQLO=mDHcY4_qQ0+noCUVg@mail.gmail.com
as determined by include-what-you-use (IWYU)
While IWYU also suggests to *add* a bunch of #include's (which is its
main purpose), this patch does not do that. In some cases, a more
specific #include replaces another less specific one.
Some manual adjustments of the automatic result:
- IWYU currently doesn't know about includes that provide global
variable declarations (like -Wmissing-variable-declarations), so
those includes are being kept manually.
- All includes for port(ability) headers are being kept for now, to
play it safe.
- No changes of catalog/pg_foo.h to catalog/pg_foo_d.h, to keep the
patch from exploding in size.
Note that this patch touches just *.c files, so nothing declared in
header files changes in hidden ways.
As a small example, in src/backend/access/transam/rmgr.c, some IWYU
pragma annotations are added to handle a special case there.
Discussion: https://www.postgresql.org/message-id/flat/af837490-6b2f-46df-ba05-37ea6a6653fc%40eisentraut.org
Now that BackendId was just another index into the proc array, it was
redundant with the 0-based proc numbers used in other places. Replace
all usage of backend IDs with proc numbers.
The only place where the term "backend id" remains is in a few pgstat
functions that expose backend IDs at the SQL level. Those IDs are now
in fact 0-based ProcNumbers too, but the documentation still calls
them "backend ids". That term still seems appropriate to describe what
the numbers are, so I let it be.
One user-visible effect is that pg_temp_0 is now a valid temp schema
name, for backend with ProcNumber 0.
Reviewed-by: Andres Freund
Discussion: https://www.postgresql.org/message-id/8171f1aa-496f-46a6-afc3-c46fe7a9b407@iki.fi
Presently, string keys are not well-supported for dshash tables.
The dshash code always copies key_size bytes into new entries'
keys, and dshash.h only provides compare and hash functions that
forward to memcmp() and tag_hash(), both of which do not stop at
the first NUL. This means that callers must pad string keys so
that the data beyond the first NUL does not adversely affect the
results of copying, comparing, and hashing the keys.
To better support string keys in dshash tables, this commit does
a couple things:
* A new copy_function field is added to the dshash_parameters
struct. This function pointer specifies how the key should be
copied into new table entries. For example, we only want to copy
up to the first NUL byte for string keys. A dshash_memcpy()
helper function is provided and used for all existing in-tree
dshash tables without string keys.
* A set of helper functions for string keys are provided. These
helper functions forward to strcmp(), strcpy(), and
string_hash(), all of which ignore data beyond the first NUL.
This commit also adjusts the DSM registry's dshash table to use the
new helper functions for string keys.
Reviewed-by: Andy Fan
Discussion: https://postgr.es/m/20240119215941.GA1322079%40nathanxps13
Commit 6b80394781 introduced integer comparison functions designed
to be as efficient as possible while avoiding overflow. This
commit makes use of these functions in many of the in-tree qsort()
comparators to help ensure transitivity. Many of these comparator
functions should also see a small performance boost.
Author: Mats Kindahl
Reviewed-by: Andres Freund, Fabrízio de Royes Mello
Discussion: https://postgr.es/m/CA%2B14426g2Wa9QuUpmakwPxXFWG_1FaY0AsApkvcTBy-YfS6uaw%40mail.gmail.com
Restoring a base backup taken in the middle of CreateDirAndVersionFile()
or write_relmap_file() would lose the function's effects. The symptom
was absence of the database directory, PG_VERSION file, or
pg_filenode.map. If missing the directory, recovery would fail. Either
missing file would not fail recovery but would render the new database
unusable. Fix CreateDirAndVersionFile() with the transam/README "action
first and then write a WAL entry" strategy. That has a side benefit of
moving filesystem mutations out of a critical section, reducing the ways
to PANIC. Fix the write_relmap_file() call with a lock acquisition, so
it interacts with checkpoints like non-CREATE DATABASE calls do.
Back-patch to v15, where commit 9c08aea6a3
introduced STRATEGY=WAL_LOG and made it the default.
Discussion: https://postgr.es/m/20240130195003.0a.nmisch@google.com
After calling smgropen(), it was not clear how long you could continue
to use the result, because various code paths including cache
invalidation could call smgrclose(), which freed the memory.
Guarantee that the object won't be destroyed until the end of the
current transaction, or in recovery, the commit/abort record that
destroys the underlying storage.
smgrclose() is now just an alias for smgrrelease(). It closes files
and forgets all state except the rlocator, but keeps the SMgrRelation
object valid.
A new smgrdestroy() function is used by rare places that know there
should be no other references to the SMgrRelation.
The short version:
* smgrclose() is now just an alias for smgrrelease(). It releases
resources, but doesn't destroy until EOX
* smgrdestroy() now frees memory, and should rarely be used.
Existing code should be unaffected, but it is now possible for code that
has an SMgrRelation object to use it repeatedly during a transaction as
long as the storage hasn't been physically dropped. Such code would
normally hold a lock on the relation.
This also replaces the "ownership" mechanism of SMgrRelations with a
pin counter. An SMgrRelation can now be "pinned", which prevents it
from being destroyed at end of transaction. There can be multiple pins
on the same SMgrRelation. In practice, the pin mechanism is only used
by the relcache, so there cannot be more than one pin on the same
SMgrRelation. Except with swap_relation_files XXX
Author: Thomas Munro, Heikki Linnakangas
Reviewed-by: Robert Haas <robertmhaas@gmail.com>
Discussion: https://www.postgresql.org/message-id/CA%2BhUKGJ8NTvqLHz6dqbQnt2c8XCki4r2QvXjBQcXpVwxTY_pvA@mail.gmail.com
Add WITHOUT OVERLAPS clause to PRIMARY KEY and UNIQUE constraints.
These are backed by GiST indexes instead of B-tree indexes, since they
are essentially exclusion constraints with = for the scalar parts of
the key and && for the temporal part.
Author: Paul A. Jungwirth <pj@illuminatedcomputing.com>
Reviewed-by: Peter Eisentraut <peter@eisentraut.org>
Reviewed-by: jian he <jian.universality@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/CA+renyUApHgSZF9-nd-a0+OPGharLQLO=mDHcY4_qQ0+noCUVg@mail.gmail.com
These support functions will transform expressions with constant
range values into direct comparisons on the range bound values,
which are frequently better-optimizable. The transformation is
skipped however if it would require double evaluation of a
volatile or expensive element expression.
Along the way, add the range opfamily OID to range typcache entries,
since load_rangetype_info has to compute that anyway and it seems
silly to duplicate the work later.
Kim Johan Andersson and Jian He, reviewed by Laurenz Albe
Discussion: https://postgr.es/m/94f64d1f-b8c0-b0c5-98bc-0793a34e0851@kimmet.dk
We've long had a policy that any toasted fields in a catalog tuple
should be pulled in-line before entering the tuple in a catalog cache.
However, that requires access to the catalog's toast table, and we'll
typically do AcceptInvalidationMessages while opening the toast table.
So it's possible that the catalog tuple is outdated by the time we
finish detoasting it. Since no cache entry exists yet, we can't
mark the entry stale during AcceptInvalidationMessages, and instead
we'll press forward and build an apparently-valid cache entry. The
upshot is that we have a race condition whereby an out-of-date entry
could be made in a backend's catalog cache, and persist there
indefinitely causing indeterminate misbehavior.
To fix, use the existing systable_recheck_tuple code to recheck
whether the catalog tuple is still up-to-date after we finish
detoasting it. If not, loop around and restart the process of
searching the catalog and constructing cache entries from the top.
The case is rare enough that this shouldn't create any meaningful
performance penalty, even in the SearchCatCacheList case where
we need to tear down and reconstruct the whole list.
Indeed, the case is so rare that AFAICT it doesn't occur during
our regression tests, and there doesn't seem to be any easy way
to build a test that would exercise it reliably. To allow
testing of the retry code paths, add logic (in USE_ASSERT_CHECKING
builds only) that randomly pretends that the recheck failed about
one time out of a thousand. This is enough to ensure that we'll
pass through the retry paths during most regression test runs.
By adding an extra level of looping, this commit creates a need
to reindent most of SearchCatCacheMiss and SearchCatCacheList.
I'll do that separately, to allow putting those changes in
.git-blame-ignore-revs.
Patch by me; thanks to Alexander Lakhin for having built a test
case to prove the bug is real, and to Xiaoran Wang for review.
Back-patch to all supported branches.
Discussion: https://postgr.es/m/1393953.1698353013@sss.pgh.pa.us
Discussion: https://postgr.es/m/CAGjhLkOoBEC9mLsnB42d3CO1vcMx71MLSEuigeABbQ8oRdA6gw@mail.gmail.com
This changes the pg_attribute field attstattarget into a nullable
field in the variable-length part of the row. If no value is set by
the user for attstattarget, it is now null instead of previously -1.
This saves space in pg_attribute and tuple descriptors for most
practical scenarios. (ATTRIBUTE_FIXED_PART_SIZE is reduced from 108
to 104.) Also, null is the semantically more correct value.
The ANALYZE code internally continues to represent the default
statistics target by -1, so that that code can avoid having to deal
with null values. But that is now contained to the ANALYZE code.
Only the DDL code deals with attstattarget possibly null.
For system columns, the field is now always null. The ANALYZE code
skips system columns anyway.
To set a column's statistics target to the default value, the new
command form ALTER TABLE ... SET STATISTICS DEFAULT can be used. (SET
STATISTICS -1 still works.)
Reviewed-by: Alvaro Herrera <alvherre@alvh.no-ip.org>
Discussion: https://www.postgresql.org/message-id/flat/4da8d211-d54d-44b9-9847-f2a9f1184c76@eisentraut.org
This GUC was intended as a debugging help in the 9.0 area when hot
standby and streaming replication were being developped, able to offer
more information at LOG level rather than DEBUGn. There are more tools
available these days that are able to offer rather equivalent
information, like pg_waldump introduced in 9.3. It is not obvious how
this facility is useful these days, so let's remove it.
Author: Bharath Rupireddy
Discussion: https://postgr.es/m/ZXEXEAUVFrvpquSd@paquier.xyz
As of commit eaa5808e8e, MemoryContextResetAndDeleteChildren() is
just a backwards compatibility macro for MemoryContextReset(). Now
that some time has passed, this macro seems more likely to create
confusion.
This commit removes the macro and replaces all remaining uses with
calls to MemoryContextReset(). Any third-party code that use this
macro will need to be adjusted to call MemoryContextReset()
instead. Since the two have behaved the same way since v9.5, such
adjustments won't produce any behavior changes for all
currently-supported versions of PostgreSQL.
Reviewed-by: Amul Sul, Tom Lane, Alvaro Herrera, Dagfinn Ilmari Mannsåker
Discussion: https://postgr.es/m/20231113185950.GA1668018%40nathanxps13
Instead of having a separate array/hash for each resource kind, use a
single array and hash to hold all kinds of resources. This makes it
possible to introduce new resource "kinds" without having to modify
the ResourceOwnerData struct. In particular, this makes it possible
for extensions to register custom resource kinds.
The old approach was to have a small array of resources of each kind,
and if it fills up, switch to a hash table. The new approach also uses
an array and a hash, but now the array and the hash are used at the
same time. The array is used to hold the recently added resources, and
when it fills up, they are moved to the hash. This keeps the access to
recent entries fast, even when there are a lot of long-held resources.
All the resource-specific ResourceOwnerEnlarge*(),
ResourceOwnerRemember*(), and ResourceOwnerForget*() functions have
been replaced with three generic functions that take resource kind as
argument. For convenience, we still define resource-specific wrapper
macros around the generic functions with the old names, but they are
now defined in the source files that use those resource kinds.
The release callback no longer needs to call ResourceOwnerForget on
the resource being released. ResourceOwnerRelease unregisters the
resource from the owner before calling the callback. That needed some
changes in bufmgr.c and some other files, where releasing the
resources previously always called ResourceOwnerForget.
Each resource kind specifies a release priority, and
ResourceOwnerReleaseAll releases the resources in priority order. To
make that possible, we have to restrict what you can do between
phases. After calling ResourceOwnerRelease(), you are no longer
allowed to remember any more resources in it or to forget any
previously remembered resources by calling ResourceOwnerForget. There
was one case where that was done previously. At subtransaction commit,
AtEOSubXact_Inval() would handle the invalidation messages and call
RelationFlushRelation(), which temporarily increased the reference
count on the relation being flushed. We now switch to the parent
subtransaction's resource owner before calling AtEOSubXact_Inval(), so
that there is a valid ResourceOwner to temporarily hold that relcache
reference.
Other end-of-xact routines make similar calls to AtEOXact_Inval()
between release phases, but I didn't see any regression test failures
from those, so I'm not sure if they could reach a codepath that needs
remembering extra resources.
There were two exceptions to how the resource leak WARNINGs on commit
were printed previously: llvmjit silently released the context without
printing the warning, and a leaked buffer io triggered a PANIC. Now
everything prints a WARNING, including those cases.
Add tests in src/test/modules/test_resowner.
Reviewed-by: Aleksander Alekseev, Michael Paquier, Julien Rouhaud
Reviewed-by: Kyotaro Horiguchi, Hayato Kuroda, Álvaro Herrera, Zhihong Yu
Reviewed-by: Peter Eisentraut, Andres Freund
Discussion: https://www.postgresql.org/message-id/cbfabeb0-cd3c-e951-a572-19b365ed314d%40iki.fi
These are functions where a lot of things happen between the
ResourceOwnerEnlarge and ResourceOwnerRemember calls. It's important
that there are no unrelated ResourceOwnerRemember calls in the code in
between, otherwise the reserved entry might be used up by the
intervening ResourceOwnerRemember and not be available at the intended
ResourceOwnerRemember call anymore. I don't see any bugs here, but the
longer the code path between the calls is, the harder it is to verify.
In bufmgr.c, there is a function similar to ResourceOwnerEnlarge,
ReservePrivateRefCountEntry(), to ensure that the private refcount
array has enough space. The ReservePrivateRefCountEntry() calls were
made at different places than the ResourceOwnerEnlargeBuffers()
calls. Move the ResourceOwnerEnlargeBuffers() and
ReservePrivateRefCountEntry() calls together for consistency.
Reviewed-by: Aleksander Alekseev, Michael Paquier, Julien Rouhaud
Reviewed-by: Kyotaro Horiguchi, Hayato Kuroda, Álvaro Herrera, Zhihong Yu
Reviewed-by: Peter Eisentraut, Andres Freund
Discussion: https://www.postgresql.org/message-id/cbfabeb0-cd3c-e951-a572-19b365ed314d%40iki.fi
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
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
If an out-of-memory error was thrown at an unfortunate time,
ensure_record_cache_typmod_slot_exists() could leak memory and leave
behind a global state that produced an infinite loop on the next call.
Fix by merging RecordCacheArray and RecordIdentifierArray into a single
array. With only one allocation or re-allocation, there is no
intermediate state.
Back-patch to all supported releases.
Reported-by: "James Pang (chaolpan)" <chaolpan@cisco.com>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/PH0PR11MB519113E738814BDDA702EDADD6EFA%40PH0PR11MB5191.namprd11.prod.outlook.com
We now create contype='n' pg_constraint rows for not-null constraints.
We propagate these constraints to other tables during operations such as
adding inheritance relationships, creating and attaching partitions and
creating tables LIKE other tables. We also spawn not-null constraints
for inheritance child tables when their parents have primary keys.
These related constraints mostly follow the well-known rules of
conislocal and coninhcount that we have for CHECK constraints, with some
adaptations: for example, as opposed to CHECK constraints, we don't
match not-null ones by name when descending a hierarchy to alter it,
instead matching by column name that they apply to. This means we don't
require the constraint names to be identical across a hierarchy.
For now, we omit them for system catalogs. Maybe this is worth
reconsidering. We don't support NOT VALID nor DEFERRABLE clauses
either; these can be added as separate features later (this patch is
already large and complicated enough.)
psql shows these constraints in \d+.
pg_dump requires some ad-hoc hacks, particularly when dumping a primary
key. We now create one "throwaway" not-null constraint for each column
in the PK together with the CREATE TABLE command, and once the PK is
created, all those throwaway constraints are removed. This avoids
having to check each tuple for nullness when the dump restores the
primary key creation.
pg_upgrading from an older release requires a somewhat brittle procedure
to create a constraint state that matches what would be created if the
database were being created fresh in Postgres 17. I have tested all the
scenarios I could think of, and it works correctly as far as I can tell,
but I could have neglected weird cases.
This patch has been very long in the making. The first patch was
written by Bernd Helmle in 2010 to add a new pg_constraint.contype value
('n'), which I (Álvaro) then hijacked in 2011 and 2012, until that one
was killed by the realization that we ought to use contype='c' instead:
manufactured CHECK constraints. However, later SQL standard
development, as well as nonobvious emergent properties of that design
(mostly, failure to distinguish them from "normal" CHECK constraints as
well as the performance implication of having to test the CHECK
expression) led us to reconsider this choice, so now the current
implementation uses contype='n' again. During Postgres 16 this had
already been introduced by commit e056c557ae, but there were some
problems mainly with the pg_upgrade procedure that couldn't be fixed in
reasonable time, so it was reverted.
In 2016 Vitaly Burovoy also worked on this feature[1] but found no
consensus for his proposed approach, which was claimed to be closer to
the letter of the standard, requiring an additional pg_attribute column
to track the OID of the not-null constraint for that column.
[1] https://postgr.es/m/CAKOSWNkN6HSyatuys8xZxzRCR-KL1OkHS5-b9qd9bf1Rad3PLA@mail.gmail.com
Author: Álvaro Herrera <alvherre@alvh.no-ip.org>
Author: Bernd Helmle <mailings@oopsware.de>
Reviewed-by: Justin Pryzby <pryzby@telsasoft.com>
Reviewed-by: Peter Eisentraut <peter.eisentraut@enterprisedb.com>
Reviewed-by: Dean Rasheed <dean.a.rasheed@gmail.com>
Revalidation of a plancache entry (after a cache invalidation event)
requires acquiring a snapshot. Normally that is harmless, but not
if the cached statement is one that needs to run without acquiring a
snapshot. We were already aware of that for TransactionStmts,
but for some reason hadn't extrapolated to the other statements that
PlannedStmtRequiresSnapshot() knows mustn't set a snapshot. This can
lead to unexpected failures of commands such as SET TRANSACTION
ISOLATION LEVEL. We can fix it in the same way, by excluding those
command types from revalidation.
However, we can do even better than that: there is no need to
revalidate for any statement type for which parse analysis, rewrite,
and plan steps do nothing interesting, which is nearly all utility
commands. To mechanize this, invent a parser function
stmt_requires_parse_analysis() that tells whether parse analysis does
anything beyond wrapping a CMD_UTILITY Query around the raw parse
tree. If that's what it does, then rewrite and plan will just
skip the Query, so that it is not possible for the same raw parse
tree to produce a different plan tree after cache invalidation.
stmt_requires_parse_analysis() is basically equivalent to the
existing function analyze_requires_snapshot(), except that for
obscure reasons that function omits ReturnStmt and CallStmt.
It is unclear whether those were oversights or intentional.
I have not been able to demonstrate a bug from not acquiring a
snapshot while analyzing these commands, but at best it seems mighty
fragile. It seems safer to acquire a snapshot for parse analysis of
these commands too, which allows making stmt_requires_parse_analysis
and analyze_requires_snapshot equivalent.
In passing this fixes a second bug, which is that ResetPlanCache
would exclude ReturnStmts and CallStmts from revalidation.
That's surely *not* safe, since they contain parsable expressions.
Per bug #18059 from Pavel Kulakov. Back-patch to all supported
branches.
Discussion: https://postgr.es/m/18059-79c692f036b25346@postgresql.org
Commit 19d8e2308b changed the list of set-of-columns that can be
returned by RelationGetIndexAttrBitmap, but didn't update its
"documentation". That was pretty hard to read already, so rewrite to
make it more comprehensible, adding the missing values while at it.
Backpatch to 16, like that commit.
Discussion: https://postgr.es/m/20230809091155.7c7f3gttjk3dj4ze@alvherre.pgsql
Reviewed-by: Tomas Vondra <tomas.vondra@enterprisedb.com>
The previous commit removed the "override" APIs. Surviving APIs facilitate
plancache.c to snapshot search_path and test whether the current value equals
a remembered snapshot.
Aleksander Alekseev. Reported by Alexander Lakhin and Noah Misch.
Discussion: https://postgr.es/m/8ffb4650-52c4-6a81-38fc-8f99be981130@gmail.com
There was already a check on the relation OID, but not its index OID and
the attributes that can be used during the syscache lookups. The two
assertions added by this commit are cheap, and actually useful for
developers to fasten the detection of incorrect data in a new entry
added in the syscache list, as these assertions are triggered during the
initial cache loading (initdb, or just backend startup), not requiring a
syscache that uses the new entry.
While on it, the relation OID check is switched to use OidIsValid().
Author: Aleksander Alekseev
Reviewed-by: Dagfinn Ilmari Mannsåker, Zhang Mingli, Michael Paquier
Discussion: https://postgr.es/m/CAJ7c6TOjUTJ0jxvWY6oJeP2-840OF8ch7qscZQsuVuotXTOS_g@mail.gmail.com
If both the passed-in plan pointer and plansource->gplan are
NULL, CachedPlanIsSimplyValid would think that the plan pointer
is possibly-valid and try to dereference it. For the one extant
call site in plpgsql, this situation doesn't normally happen
which is why we've not noticed. However, it appears to be possible
if the previous use of the cached plan failed, as per report from
Justin Pryzby. Add an extra check to prevent crashing.
Back-patch to v13 where this code was added.
Discussion: https://postgr.es/m/ZLlV+STFz1l/WhAQ@telsasoft.com
Based on how postgres.h foes the Oid <-> Datum conversion, there is no
existing bugs but let's be consistent. 17 spots have been noticed as
incorrectly passing down Oids rather than Datums. Aleksander got one,
Zhang two and I the rest.
Author: Michael Paquier, Aleksander Alekseev, Zhang Mingli
Discussion: https://postgr.es/m/ZLUhqsqQN1MOaxdw@paquier.xyz
Commit 89e46da5e5 allowed using BTREE indexes that are neither
PRIMARY KEY nor REPLICA IDENTITY on the subscriber during apply of
update/delete. This patch extends that functionality to also allow HASH
indexes.
We explored supporting other index access methods as well but they don't
have a fixed strategy for equality operation which is required by the
current infrastructure in logical replication to scan the indexes.
Author: Kuroda Hayato
Reviewed-by: Peter Smith, Onder Kalaci, Amit Kapila
Discussion: https://postgr.es/m/TYAPR01MB58669D7414E59664E17A5827F522A@TYAPR01MB5866.jpnprd01.prod.outlook.com
RelationReloadIndexInfo() is a fast-path used for index reloads in the
relation cache, and it has always forgotten about updating
indisreplident, which is something that would happen after an index is
selected for a replica identity. This can lead to incorrect cache
information provided when executing a command in a transaction context
that updates indisreplident.
None of the code paths currently on HEAD that need to check upon
pg_index.indisreplident fetch its value from the relation cache, always
relying on a fresh copy on the syscache. Unfortunately, this may not be
the case of out-of-core code, that could see out-of-date value.
Author: Shruthi Gowda
Reviewed-by: Robert Haas, Dilip Kumar, Michael Paquier
Discussion: https://postgr.es/m/CAASxf_PBcxax0wW-3gErUyftZ0XrCs3Lrpuhq4-Z3Fak1DoW7Q@mail.gmail.com
Backpatch-through: 11
BuildEventTriggerCache sets up a context "EventTriggerCache" which
house a hash named "Event Trigger Cache", which in turn creates a
context with the table name. This generated log output for memory
context dumps like below:
LOG: level: 2; EventTriggerCache: 8192 total in 1 blocks; 7928 free (4 chunks); 264 used
LOG: level: 3; Event Trigger Cache: 8192 total in 1 blocks; 2616 free (0 chunks); 5576 used
This renames the hash to ensure that the hash context has a unique
name for easier log reading and debugging.
Discussion: https://postgr.es/m/5EDC969E-CAE3-4CBD-965E-3B8A1294CFA4@yesql.se
exec_parse_message() wants to create a cached plan in all cases,
including for empty input. The empty-input path does not have
a test for being in an aborted transaction, making it possible
that plancache.c will fail due to trying to do database lookups
even though there's no real work to do.
One solution would be to throw an aborted-transaction error in
this path too, but it's not entirely clear whether the lack of
such an error was intentional or whether some clients might be
relying on non-error behavior. Instead, let's hack plancache.c
so that it treats empty statements with the same logic it
already had for transaction control commands, ensuring that it
can soldier through even in an already-aborted transaction.
Per bug #17983 from Alexander Lakhin. Back-patch to all
supported branches.
Discussion: https://postgr.es/m/17983-da4569fcb878672e@postgresql.org
Run pgindent, pgperltidy, and reformat-dat-files.
This set of diffs is a bit larger than typical. We've updated to
pg_bsd_indent 2.1.2, which properly indents variable declarations that
have multi-line initialization expressions (the continuation lines are
now indented one tab stop). We've also updated to perltidy version
20230309 and changed some of its settings, which reduces its desire to
add whitespace to lines to make assignments etc. line up. Going
forward, that should make for fewer random-seeming changes to existing
code.
Discussion: https://postgr.es/m/20230428092545.qfb3y5wcu4cm75ur@alvherre.pgsql
Commit 47bb9db75 taught AcquireExecutorLocks to re-acquire locks
on views using data from their RTE_SUBQUERY replacements, but
it now seems like we should make AcquirePlannerLocks do the same.
In this way, if a view has been redefined, we will notice that
a bit earlier while checking validity of a cached plan and thereby
avoid some wasted work.
Report and patch by Amit Langote.
Discussion: https://postgr.es/m/CA+HiwqH0xZOQ+GQAdKeckY1R4NOeHdzhtfxkAMJLSchpapNk5w@mail.gmail.com
When extracting an attr from a cached tuple in the syscache with
SysCacheGetAttr the isnull parameter must be checked in case the
attr cannot be NULL. For cases when this is known beforehand, a
wrapper is introduced which perform the errorhandling internally
on behalf of the caller, invoking an elog in case of a NULL attr.
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Peter Eisentraut <peter.eisentraut@enterprisedb.com>
Reviewed-by: David Rowley <dgrowleyml@gmail.com>
Discussion: https://postgr.es/m/AD76405E-DB45-46B6-941F-17B1EB3A9076@yesql.se
When determining whether an index update may be skipped by using HOT, we
can ignore attributes indexed by block summarizing indexes without
references to individual tuples that need to be cleaned up.
A new type TU_UpdateIndexes provides a signal to the executor to
determine which indexes to update - no indexes, all indexes, or only the
summarizing indexes.
This also removes rd_indexattr list, and replaces it with rd_attrsvalid
flag. The list was not used anywhere, and a simple flag is sufficient.
This was originally committed as 5753d4ee32, but then got reverted by
e3fcca0d0d because of correctness issues.
Original patch by Josef Simanek, various fixes and improvements by Tomas
Vondra and me.
Authors: Matthias van de Meent, Josef Simanek, Tomas Vondra
Reviewed-by: Tomas Vondra, Alvaro Herrera
Discussion: https://postgr.es/m/05ebcb44-f383-86e3-4f31-0a97a55634cf@enterprisedb.com
Discussion: https://postgr.es/m/CAFp7QwpMRGcDAQumN7onN9HjrJ3u4X3ZRXdGFT0K5G2JWvnbWg%40mail.gmail.com
The existing comments in load_relcache_init_file() were not flexible
when new entries were added at the end, so they ended up a bit wrong.
Simplify the comments to avoid this issue.
Alvaro Herrera
Tom Lane
Alexander Korotkov
Peter Eisentraut
Heikki Linnakangas
Michael Paquier
Nathan Bossart
Noah Misch
Bruce Momjian
Thomas Munro
Amit Kapila
Daniel Gustafsson
Tomas Vondra