The output plugin accepts a new parameter (messages) that controls if
logical decoding messages are written into the replication stream. It is
useful for those clients that use pgoutput as an output plugin and needs
to process messages that were written by pg_logical_emit_message().
Although logical streaming replication protocol supports logical
decoding messages now, logical replication does not use this feature yet.
Author: David Pirotte, Euler Taveira
Reviewed-by: Euler Taveira, Andres Freund, Ashutosh Bapat, Amit Kapila
Discussion: https://postgr.es/m/CADK3HHJ-+9SO7KuRLH=9Wa1rAo60Yreq1GFNkH_kd0=CdaWM+A@mail.gmail.com
Instead of using multiple parameters in parse_ouput_parameters function
signature, use the struct PGOutputData that encapsulates all pgoutput
options. It will be useful for future work where we need to add other
options in pgoutput.
Author: Euler Taveira
Reviewed-by: Amit Kapila
Discussion: https://postgr.es/m/CADK3HHJ-+9SO7KuRLH=9Wa1rAo60Yreq1GFNkH_kd0=CdaWM+A@mail.gmail.com
Commit 49f49def took entirely the wrong approach to fixing this issue.
Just allocate a local buffer access strategy in each individual worker
instead of trying to propagate state. This state was never propagated
by parallel VACUUM in the first place.
It looks like the only reason that this worked following commit 40d964ec
was that it involved static global variables, which are initialized to 0
per the C standard.
A more comprehensive fix may be necessary, even on HEAD. This fix
should at least get the buildfarm green once again.
Thanks once again to Thomas Munro for continued off-list assistance with
the issue.
Not much to say here: does what it says on the tin.
We steal a previously-always-zero bit from the nextOffset
field of leaf index tuples in order to track whether there
is a nulls bitmap. Otherwise it works about like included
columns in other index types.
Pavel Borisov, reviewed by Andrey Borodin and Anastasia Lubennikova,
and rather heavily editorialized on by me
Discussion: https://postgr.es/m/CALT9ZEFi-vMp4faht9f9Junb1nO3NOSjhpxTmbm1UGLMsLqiEQ@mail.gmail.com
Parallel VACUUM relied on global variable state from the leader process
being propagated to workers on fork(). Commit b4af70cb removed most
uses of global variables inside vacuumlazy.c, but did not account for
the buffer access strategy state.
To fix, propagate the state through shared memory instead.
Per buildfarm failures on elver, curculio, and morepork.
Many thanks to Thomas Munro for off-list assistance with this issue.
Reorganize the state struct used by VACUUM -- group related items
together to make it easier to understand. Also stop relying on stack
variables inside lazy_scan_heap() -- move those into the state struct
instead. Doing things this way simplifies large groups of related
functions whose function signatures had a lot of unnecessary redundancy.
Switch over to using int64 for the struct fields used to count things
that are reported to the user via log_autovacuum and VACUUM VERBOSE
output. We were using double, but that doesn't seem to have any
advantages. Using int64 makes it possible to add assertions that verify
that the first pass over the heap (pruning) encounters precisely the
same number of LP_DEAD items that get deleted from indexes later on, in
the second pass over the heap. These assertions will be added in later
commits.
Finally, adjust the signatures of functions with IndexBulkDeleteResult
pointer arguments in cases where there was ambiguity about whether or
not the argument relates to a single index or all indexes. Functions
now use the idiom that both ambulkdelete() and amvacuumcleanup() have
always used (where appropriate): accept a mutable IndexBulkDeleteResult
pointer argument, and return a result IndexBulkDeleteResult pointer to
caller.
Author: Peter Geoghegan <pg@bowt.ie>
Reviewed-By: Masahiko Sawada <sawada.mshk@gmail.com>
Reviewed-By: Robert Haas <robertmhaas@gmail.com>
Discussion: https://postgr.es/m/CAH2-WzkeOSYwC6KNckbhk2b1aNnWum6Yyn0NKP9D-Hq1LGTDPw@mail.gmail.com
A commonly requested use-case is to have a role who can run an
unfettered pg_dump without having to explicitly GRANT that user access
to all tables, schemas, et al, without that role being a superuser.
This address that by adding a "pg_read_all_data" role which implicitly
gives any member of this role SELECT rights on all tables, views and
sequences, and USAGE rights on all schemas.
As there may be cases where it's also useful to have a role who has
write access to all objects, pg_write_all_data is also introduced and
gives users implicit INSERT, UPDATE and DELETE rights on all tables,
views and sequences.
These roles can not be logged into directly but instead should be
GRANT'd to a role which is able to log in. As noted in the
documentation, if RLS is being used then an administrator may (or may
not) wish to set BYPASSRLS on the login role which these predefined
roles are GRANT'd to.
Reviewed-by: Georgios Kokolatos
Discussion: https://postgr.es/m/20200828003023.GU29590@tamriel.snowman.net
Maxim Orlov reported that the shutdown of standby server could result in
the following assertion failure. The cause of this issue was that,
when the shutdown caused the startup process to exit, recovery-time
transaction tracking was not shut down even if it's already initialized,
and some locks the tracked transactions were holding could not be released.
At this situation, if other process was invoked and the PGPROC entry that
the startup process used was assigned to it, it found such unreleased locks
and caused the assertion failure, during the initialization of it.
TRAP: FailedAssertion("SHMQueueEmpty(&(MyProc->myProcLocks[i]))"
This commit fixes this issue by making the startup process shut down
transaction tracking and release all locks, at the exit of it.
Back-patch to all supported branches.
Reported-by: Maxim Orlov
Author: Fujii Masao
Reviewed-by: Maxim Orlov
Discussion: https://postgr.es/m/ad4ce692cc1d89a093b471ab1d969b0b@postgrespro.ru
spg_box_quad_leaf_consistent unconditionally returned the leaf
datum as leafValue, even though in its usage for poly_ops that
value is of completely the wrong type.
In versions before 12, that was harmless because the core code did
nothing with leafValue in non-index-only scans ... but since commit
2a6368343, if we were doing a KNN-style scan, spgNewHeapItem would
unconditionally try to copy the value using the wrong datatype
parameters. Said copying is a waste of time and space if we're not
going to return the data, but it accidentally failed to fail until
I fixed the datatype confusion in ac9099fc1.
Hence, change spgNewHeapItem to not copy the datum unless we're
actually going to return it later. This saves cycles and dodges
the question of whether lossy opclasses are returning the right
type. Also change spg_box_quad_leaf_consistent to not return
data that might be of the wrong type, as insurance against
somebody introducing a similar bug into the core code in future.
It seems like a good idea to back-patch these two changes into
v12 and v13, although I'm afraid to change spgNewHeapItem's
mistaken idea of which datatype to use in those branches.
Per buildfarm results from ac9099fc1.
Discussion: https://postgr.es/m/3728741.1617381471@sss.pgh.pa.us
According to the documentation, the attType passed to the opclass
config function (and also relied on by the core code) is the type
of the heap column or expression being indexed. But what was
actually being passed was the type stored for the index column.
This made no difference for user-defined SP-GiST opclasses,
because we weren't allowing the STORAGE clause of CREATE OPCLASS
to be used, so the two types would be the same. But it's silly
not to allow that, seeing that the built-in poly_ops opclass
has a different value for opckeytype than opcintype, and that if you
want to do lossy storage then the types must really be different.
(Thus, user-defined opclasses doing lossy storage had to lie about
what type is in the index.) Hence, remove the restriction, and make
sure that we use the input column type not opckeytype where relevant.
For reasons of backwards compatibility with existing user-defined
opclasses, we can't quite insist that the specified leafType match
the STORAGE clause; instead just add an amvalidate() warning if
they don't match.
Also fix some bugs that would only manifest when trying to return
index entries when attType is different from attLeafType. It's not
too surprising that these have not been reported, because the only
usual reason for such a difference is to store the leaf value
lossily, rendering index-only scans impossible.
Add a src/test/modules module to exercise cases where attType is
different from attLeafType and yet index-only scan is supported.
Discussion: https://postgr.es/m/3728741.1617381471@sss.pgh.pa.us
When calling sort_expanded_ranges() we need to remember the return
value, because the function sorts and also deduplicates the ranges. So
the number of ranges may decrease. brin_minmax_multi_union failed to do
that, which resulted in crashes due to bogus ranges (equal minval/maxval
but not marked as compacted).
Reported-by: Jaime Casanova
Discussion: https://postgr.es/m/20210404052550.GA4376%40ahch-to
The BRIN minmax-multi consistent function incorrectly assumed it can
lookup an operator, and then swap the arguments to get the commutator.
For example <(a,b) would be called as <(b,a) to get >(a,b). This works
when the arguments are of the same type, but with cross-type opclasses
this fails. We can't swap <(float4,float8) arguments, for example.
Fixed by passing arguments in the right order.
Discussion: https://postgr.es/m/CAJKUy5jLZFLCxyxfT%3DMfK5mtPfSzHA1rVLowR-j4RRsFVvKm7A%40mail.gmail.com
The distance calculation ignored the mask, unlike the inet comparator,
which resulted in negative distance in some cases. Fixed by applying the
mask in brin_minmax_multi_distance_inet. I've considered simply calling
inetmi() to calculate the delta, but that does not consider mask either.
Reviewed-by: Zhihong Yu
Discussion: https://postgr.es/m/1a0a7b9d-9bda-e3a2-7fa4-88f15042a051%40enterprisedb.com
The distance calculation for interval type was treating months as having
31 days, which is inconsistent with the interval comparator (using 30
days). Due to this it was possible to get negative distance (b-a) when
(a<b), trigerring an assert.
Fixed by adopting the same logic as interval_cmp_value.
Reported-by: Jaime Casanova
Discussion: https://postgr.es/m/CAJKUy5jKH0Xhneau2mNftNPtTy-BVgQfXc8zQkEvRvBHfeUThQ%40mail.gmail.com
pgstat_report_wait_start() and pgstat_report_wait_end() required two
conditional branches so far. One to check if MyProc is NULL, the other to
check if pgstat_track_activities is set. As wait events are used around
comparatively lightweight operations, and are inlined (reducing branch
predictor effectiveness), that's not great.
The dependency on MyProc has a second disadvantage: Low-level subsystems, like
storage/file/fd.c, report wait events, but architecturally it is preferable
for them to not depend on inter-process subsystems like proc.h (defining
PGPROC). After this change including pgstat.h (nor obviously its
sub-components like backend_status.h, wait_event.h, ...) does not pull in IPC
related headers anymore.
These goals, efficiency and abstraction, are achieved by having
pgstat_report_wait_start/end() not interact with MyProc, but instead a new
my_wait_event_info variable. At backend startup it points to a local variable,
removing the need to check for MyProc being NULL. During process
initialization my_wait_event_info is redirected to MyProc->wait_event_info. At
shutdown this is reversed. Because wait event reporting now does not need to
know about where the wait event is stored, it does not need to know about
PGPROC anymore.
The removal of the branch for checking pgstat_track_activities is simpler:
Don't check anymore. The cost due to the branch are often higher than the
store - and even if not, pgstat_track_activities is rarely disabled.
The main motivator to commit this work now is that removing the (indirect)
pgproc.h include from pgstat.h simplifies a patch to move statistics reporting
to shared memory (which still has a chance to get into 14).
Author: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/20210402194458.2vu324hkk2djq6ce@alap3.anarazel.de
Backend status (supporting pg_stat_activity) and command
progress (supporting pg_stat_progress*) related code is largely
independent from the rest of pgstat.[ch] (supporting views like
pg_stat_all_tables that accumulate data over time). See also
a333476b92.
This commit doesn't rename the function names to make the distinction
from the rest of pgstat_ clearer - that'd be more invasive and not
clearly beneficial. If we were to decide to do such a rename at some
point, it's better done separately from moving the code as well.
Robert's review was of an earlier version.
Reviewed-By: Robert Haas <robertmhaas@gmail.com>
Discussion: https://postgr.es/m/20210316195440.twxmlov24rr2nxrg@alap3.anarazel.de
Similarly to the cryptohash implementations, this refactors the existing
HMAC code into a single set of APIs that can be plugged with any crypto
libraries PostgreSQL is built with (only OpenSSL currently). If there
is no such libraries, a fallback implementation is available. Those new
APIs are designed similarly to the existing cryptohash layer, so there
is no real new design here, with the same logic around buffer bound
checks and memory handling.
HMAC has a dependency on cryptohashes, so all the cryptohash types
supported by cryptohash{_openssl}.c can be used with HMAC. This
refactoring is an advantage mainly for SCRAM, that included its own
implementation of HMAC with SHA256 without relying on the existing
crypto libraries even if PostgreSQL was built with their support.
This code has been tested on Windows and Linux, with and without
OpenSSL, across all the versions supported on HEAD from 1.1.1 down to
1.0.1. I have also checked that the implementations are working fine
using some sample results, a custom extension of my own, and doing
cross-checks across different major versions with SCRAM with the client
and the backend.
Author: Michael Paquier
Reviewed-by: Bruce Momjian
Discussion: https://postgr.es/m/X9m0nkEJEzIPXjeZ@paquier.xyz
The wait event related code is independent from the rest of the
pgstat.[ch] code, of nontrivial size and changes on a regular
basis. Put it into its own set of files.
As there doesn't seem to be a good pre-existing directory for code
like this, add src/backend/utils/activity.
Reviewed-By: Robert Haas <robertmhaas@gmail.com>
Discussion: https://postgr.es/m/20210316195440.twxmlov24rr2nxrg@alap3.anarazel.de
Testing if an unsigned variable is >= 0 is pretty pointless.
There's likely enough code in remove_cache_entry() to verify the cache
memory accounting is correct in assert enabled builds. These Asserts
were not adding much extra cover, even if they had been checking >= 0 on a
signed variable.
Reported-by: Andres Freund
Discussion: https://postgr.es/m/20210402204734.6mo3nfacnljlicgn@alap3.anarazel.de
Provide a new GUC check_client_connection_interval that can be used to
check whether the client connection has gone away, while running very
long queries. It is disabled by default.
For now this uses a non-standard Linux extension (also adopted by at
least one other OS). POLLRDHUP is not defined by POSIX, and other OSes
don't have a reliable way to know if a connection was closed without
actually trying to read or write.
In future we might consider trying to send a no-op/heartbeat message
instead, but that could require protocol changes.
Author: Sergey Cherkashin <s.cherkashin@postgrespro.ru>
Author: Thomas Munro <thomas.munro@gmail.com>
Reviewed-by: Thomas Munro <thomas.munro@gmail.com>
Reviewed-by: Tatsuo Ishii <ishii@sraoss.co.jp>
Reviewed-by: Konstantin Knizhnik <k.knizhnik@postgrespro.ru>
Reviewed-by: Zhihong Yu <zyu@yugabyte.com>
Reviewed-by: Andres Freund <andres@anarazel.de>
Reviewed-by: Maksim Milyutin <milyutinma@gmail.com>
Reviewed-by: Tsunakawa, Takayuki/綱川 貴之 <tsunakawa.takay@fujitsu.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us> (much earlier version)
Discussion: https://postgr.es/m/77def86b27e41f0efcba411460e929ae%40postgrespro.ru
Commit dd136052b established a policy that error message FILE items
should include only the base name of the reporting source file, for
uniformity and succinctness. We now observe that some Windows compilers
use backslashes in __FILE__ strings, so truncate at backslashes as well.
This is expected to fix some platform variation in the results of the
new libpq_pipeline test module.
Discussion: https://postgr.es/m/3650140.1617372290@sss.pgh.pa.us
The caller of pgstat_report_replslot() passes int64 values to the function.
Also the function stores those values in PgStat_Counter (i.e., int64) fields
of PgStat_MsgReplSlot struct. But previously the function used "int" as
the data types of some arguments for those values, which could lead to
the overflow of values.
To avoid this risk, this commit fixes pgstat_report_replslot() to use
PgStat_Counter type for the arguments. Since they are the statistics counters,
PgStat_Counter, the data type used for counters, is used for them
instead of int64.
Reported-by: Vignesh C
Author: Vignesh C
Reviewed-by: Jeevan Ladhe, Fujii Masao
Discussion: https://postgr.es/m/CALDaNm080OpG=ZwOb0i8EyChH5SyHAMFWJCKaKTXmrfvJLbgaA@mail.gmail.com
Here we add a new executor node type named "Result Cache". The planner
can include this node type in the plan to have the executor cache the
results from the inner side of parameterized nested loop joins. This
allows caching of tuples for sets of parameters so that in the event that
the node sees the same parameter values again, it can just return the
cached tuples instead of rescanning the inner side of the join all over
again. Internally, result cache uses a hash table in order to quickly
find tuples that have been previously cached.
For certain data sets, this can significantly improve the performance of
joins. The best cases for using this new node type are for join problems
where a large portion of the tuples from the inner side of the join have
no join partner on the outer side of the join. In such cases, hash join
would have to hash values that are never looked up, thus bloating the hash
table and possibly causing it to multi-batch. Merge joins would have to
skip over all of the unmatched rows. If we use a nested loop join with a
result cache, then we only cache tuples that have at least one join
partner on the outer side of the join. The benefits of using a
parameterized nested loop with a result cache increase when there are
fewer distinct values being looked up and the number of lookups of each
value is large. Also, hash probes to lookup the cache can be much faster
than the hash probe in a hash join as it's common that the result cache's
hash table is much smaller than the hash join's due to result cache only
caching useful tuples rather than all tuples from the inner side of the
join. This variation in hash probe performance is more significant when
the hash join's hash table no longer fits into the CPU's L3 cache, but the
result cache's hash table does. The apparent "random" access of hash
buckets with each hash probe can cause a poor L3 cache hit ratio for large
hash tables. Smaller hash tables generally perform better.
The hash table used for the cache limits itself to not exceeding work_mem
* hash_mem_multiplier in size. We maintain a dlist of keys for this cache
and when we're adding new tuples and realize we've exceeded the memory
budget, we evict cache entries starting with the least recently used ones
until we have enough memory to add the new tuples to the cache.
For parameterized nested loop joins, we now consider using one of these
result cache nodes in between the nested loop node and its inner node. We
determine when this might be useful based on cost, which is primarily
driven off of what the expected cache hit ratio will be. Estimating the
cache hit ratio relies on having good distinct estimates on the nested
loop's parameters.
For now, the planner will only consider using a result cache for
parameterized nested loop joins. This works for both normal joins and
also for LATERAL type joins to subqueries. It is possible to use this new
node for other uses in the future. For example, to cache results from
correlated subqueries. However, that's not done here due to some
difficulties obtaining a distinct estimation on the outer plan to
calculate the estimated cache hit ratio. Currently we plan the inner plan
before planning the outer plan so there is no good way to know if a result
cache would be useful or not since we can't estimate the number of times
the subplan will be called until the outer plan is generated.
The functionality being added here is newly introducing a dependency on
the return value of estimate_num_groups() during the join search.
Previously, during the join search, we only ever needed to perform
selectivity estimations. With this commit, we need to use
estimate_num_groups() in order to estimate what the hit ratio on the
result cache will be. In simple terms, if we expect 10 distinct values
and we expect 1000 outer rows, then we'll estimate the hit ratio to be
99%. Since cache hits are very cheap compared to scanning the underlying
nodes on the inner side of the nested loop join, then this will
significantly reduce the planner's cost for the join. However, it's
fairly easy to see here that things will go bad when estimate_num_groups()
incorrectly returns a value that's significantly lower than the actual
number of distinct values. If this happens then that may cause us to make
use of a nested loop join with a result cache instead of some other join
type, such as a merge or hash join. Our distinct estimations have been
known to be a source of trouble in the past, so the extra reliance on them
here could cause the planner to choose slower plans than it did previous
to having this feature. Distinct estimations are also fairly hard to
estimate accurately when several tables have been joined already or when a
WHERE clause filters out a set of values that are correlated to the
expressions we're estimating the number of distinct value for.
For now, the costing we perform during query planning for result caches
does put quite a bit of faith in the distinct estimations being accurate.
When these are accurate then we should generally see faster execution
times for plans containing a result cache. However, in the real world, we
may find that we need to either change the costings to put less trust in
the distinct estimations being accurate or perhaps even disable this
feature by default. There's always an element of risk when we teach the
query planner to do new tricks that it decides to use that new trick at
the wrong time and causes a regression. Users may opt to get the old
behavior by turning the feature off using the enable_resultcache GUC.
Currently, this is enabled by default. It remains to be seen if we'll
maintain that setting for the release.
Additionally, the name "Result Cache" is the best name I could think of
for this new node at the time I started writing the patch. Nobody seems
to strongly dislike the name. A few people did suggest other names but no
other name seemed to dominate in the brief discussion that there was about
names. Let's allow the beta period to see if the current name pleases
enough people. If there's some consensus on a better name, then we can
change it before the release. Please see the 2nd discussion link below
for the discussion on the "Result Cache" name.
Author: David Rowley
Reviewed-by: Andy Fan, Justin Pryzby, Zhihong Yu, Hou Zhijie
Tested-By: Konstantin Knizhnik
Discussion: https://postgr.es/m/CAApHDvrPcQyQdWERGYWx8J%2B2DLUNgXu%2BfOSbQ1UscxrunyXyrQ%40mail.gmail.com
Discussion: https://postgr.es/m/CAApHDvq=yQXr5kqhRviT2RhNKwToaWr9JAN5t+5_PzhuRJ3wvg@mail.gmail.com
The existing convention in SP-GiST is that any pass-by-value datatype
is stored in Datum representation, i.e. it's of width sizeof(Datum)
even when typlen is less than that. This is okay, or at least it's
too late to change it, for prefix datums and node-label datums in inner
(upper) tuples. But it's problematic for leaf datums, because we'd
prefer those to be stored in Postgres' standard on-disk representation
so that we can easily extend leaf tuples to carry additional "included"
columns.
I believe, however, that we can get away with just up and changing that.
This would be an unacceptable on-disk-format break, but there are two
big mitigating factors:
1. It seems quite unlikely that there are any SP-GiST opclasses out
there that use pass-by-value leaf datatypes. Certainly none of the
ones in core do, nor has codesearch.debian.net heard of any. Given
what SP-GiST is good for, it's hard to conceive of a use-case where
the leaf-level values would be both small and fixed-width. (As an
example, if you wanted to index text values with the leaf level being
just a byte, then every text string would have to be represented
with one level of inner tuple per preceding byte, which would be
horrendously space-inefficient and slow to access. You always want
to use as few inner-tuple levels as possible, leaving as much as
possible in the leaf values.)
2. Even granting that you have such an index, this change only
breaks things on big-endian machines. On little-endian, the high
order bytes of the Datum format will now just appear to be alignment
padding space.
So, change the code to store pass-by-value leaf datums in their
usual on-disk form. Inner-tuple datums are not touched.
This is extracted from a larger patch that intends to add support for
"included" columns. I'm committing it separately for visibility in
our commit logs.
Pavel Borisov and Tom Lane, reviewed by Andrey Borodin
Discussion: https://postgr.es/m/CALT9ZEFi-vMp4faht9f9Junb1nO3NOSjhpxTmbm1UGLMsLqiEQ@mail.gmail.com
Through various refactorings over time, the extract(timezone_minute
from time with time zone) and extract(timezone_minute from timestamp
with time zone) implementations ended up with two different but
equally nonsensical formulas by using SECS_PER_MINUTE and
MINS_PER_HOUR interchangeably. Since those two are of course both the
same number, the formulas do work, but for readability, fix them to be
semantically correct.
This gives a small performance gain, by reducing the number of calls
to the conversion/verification function, and letting it work with
larger inputs. Also, reorganizing the input pipeline makes it easier
to parallelize the input parsing: after the input has been converted
to the database encoding, the next stage of finding the newlines can
be done in parallel, because there cannot be any newline chars
"embedded" in multi-byte characters in the encodings that we support
as server encodings.
This changes behavior in one corner case: if client and server
encodings are the same single-byte encoding (e.g. latin1), previously
the input would not be checked for zero bytes ('\0'). Any fields
containing zero bytes would be truncated at the zero. But if encoding
conversion was needed, the conversion routine would throw an error on
the zero. After this commit, the input is always checked for zeros.
Reviewed-by: John Naylor
Discussion: https://www.postgresql.org/message-id/e7861509-3960-538a-9025-b75a61188e01%40iki.fi
With the 'noError' argument, you can try to convert a buffer without
knowing the character boundaries beforehand. The functions now need to
return the number of input bytes successfully converted.
This is is a backwards-incompatible change, if you have created a custom
encoding conversion with CREATE CONVERSION. This adds a check to
pg_upgrade for that, refusing the upgrade if there are any user-defined
encoding conversions. Custom conversions are very rare, there are no
commonly used extensions that I know of that uses that feature. No other
objects can depend on conversions, so if you do have one, you can fairly
easily drop it before upgrading, and recreate it after the upgrade with
an updated version.
Add regression tests for built-in encoding conversions. This doesn't cover
every conversion, but it covers all the internal functions in conv.c that
are used to implement the conversions.
Reviewed-by: John Naylor
Discussion: https://www.postgresql.org/message-id/e7861509-3960-538a-9025-b75a61188e01%40iki.fi
It is possible that while decoding a prepared transaction, it gets aborted
concurrently via a ROLLBACK PREPARED command. In that case, we were
skipping all the changes and directly sending Rollback Prepared when we
find the same in WAL. However, the downstream has no idea of the GID of
such a transaction. So, ensure to send prepare even when a concurrent
abort is detected.
Author: Ajin Cherian
Reviewed-by: Markus Wanner, Amit Kapila
Discussion: https://postgr.es/m/f82133c6-6055-b400-7922-97dae9f2b50b@enterprisedb.com
This removes "Add Result Cache executor node". It seems that something
weird is going on with the tracking of cache hits and misses as
highlighted by many buildfarm animals. It's not yet clear what the
problem is as other parts of the plan indicate that the cache did work
correctly, it's just the hits and misses that were being reported as 0.
This is especially a bad time to have the buildfarm so broken, so
reverting before too many more animals go red.
Discussion: https://postgr.es/m/CAApHDvq_hydhfovm4=izgWs+C5HqEeRScjMbOgbpC-jRAeK3Yw@mail.gmail.com
Here we add a new executor node type named "Result Cache". The planner
can include this node type in the plan to have the executor cache the
results from the inner side of parameterized nested loop joins. This
allows caching of tuples for sets of parameters so that in the event that
the node sees the same parameter values again, it can just return the
cached tuples instead of rescanning the inner side of the join all over
again. Internally, result cache uses a hash table in order to quickly
find tuples that have been previously cached.
For certain data sets, this can significantly improve the performance of
joins. The best cases for using this new node type are for join problems
where a large portion of the tuples from the inner side of the join have
no join partner on the outer side of the join. In such cases, hash join
would have to hash values that are never looked up, thus bloating the hash
table and possibly causing it to multi-batch. Merge joins would have to
skip over all of the unmatched rows. If we use a nested loop join with a
result cache, then we only cache tuples that have at least one join
partner on the outer side of the join. The benefits of using a
parameterized nested loop with a result cache increase when there are
fewer distinct values being looked up and the number of lookups of each
value is large. Also, hash probes to lookup the cache can be much faster
than the hash probe in a hash join as it's common that the result cache's
hash table is much smaller than the hash join's due to result cache only
caching useful tuples rather than all tuples from the inner side of the
join. This variation in hash probe performance is more significant when
the hash join's hash table no longer fits into the CPU's L3 cache, but the
result cache's hash table does. The apparent "random" access of hash
buckets with each hash probe can cause a poor L3 cache hit ratio for large
hash tables. Smaller hash tables generally perform better.
The hash table used for the cache limits itself to not exceeding work_mem
* hash_mem_multiplier in size. We maintain a dlist of keys for this cache
and when we're adding new tuples and realize we've exceeded the memory
budget, we evict cache entries starting with the least recently used ones
until we have enough memory to add the new tuples to the cache.
For parameterized nested loop joins, we now consider using one of these
result cache nodes in between the nested loop node and its inner node. We
determine when this might be useful based on cost, which is primarily
driven off of what the expected cache hit ratio will be. Estimating the
cache hit ratio relies on having good distinct estimates on the nested
loop's parameters.
For now, the planner will only consider using a result cache for
parameterized nested loop joins. This works for both normal joins and
also for LATERAL type joins to subqueries. It is possible to use this new
node for other uses in the future. For example, to cache results from
correlated subqueries. However, that's not done here due to some
difficulties obtaining a distinct estimation on the outer plan to
calculate the estimated cache hit ratio. Currently we plan the inner plan
before planning the outer plan so there is no good way to know if a result
cache would be useful or not since we can't estimate the number of times
the subplan will be called until the outer plan is generated.
The functionality being added here is newly introducing a dependency on
the return value of estimate_num_groups() during the join search.
Previously, during the join search, we only ever needed to perform
selectivity estimations. With this commit, we need to use
estimate_num_groups() in order to estimate what the hit ratio on the
result cache will be. In simple terms, if we expect 10 distinct values
and we expect 1000 outer rows, then we'll estimate the hit ratio to be
99%. Since cache hits are very cheap compared to scanning the underlying
nodes on the inner side of the nested loop join, then this will
significantly reduce the planner's cost for the join. However, it's
fairly easy to see here that things will go bad when estimate_num_groups()
incorrectly returns a value that's significantly lower than the actual
number of distinct values. If this happens then that may cause us to make
use of a nested loop join with a result cache instead of some other join
type, such as a merge or hash join. Our distinct estimations have been
known to be a source of trouble in the past, so the extra reliance on them
here could cause the planner to choose slower plans than it did previous
to having this feature. Distinct estimations are also fairly hard to
estimate accurately when several tables have been joined already or when a
WHERE clause filters out a set of values that are correlated to the
expressions we're estimating the number of distinct value for.
For now, the costing we perform during query planning for result caches
does put quite a bit of faith in the distinct estimations being accurate.
When these are accurate then we should generally see faster execution
times for plans containing a result cache. However, in the real world, we
may find that we need to either change the costings to put less trust in
the distinct estimations being accurate or perhaps even disable this
feature by default. There's always an element of risk when we teach the
query planner to do new tricks that it decides to use that new trick at
the wrong time and causes a regression. Users may opt to get the old
behavior by turning the feature off using the enable_resultcache GUC.
Currently, this is enabled by default. It remains to be seen if we'll
maintain that setting for the release.
Additionally, the name "Result Cache" is the best name I could think of
for this new node at the time I started writing the patch. Nobody seems
to strongly dislike the name. A few people did suggest other names but no
other name seemed to dominate in the brief discussion that there was about
names. Let's allow the beta period to see if the current name pleases
enough people. If there's some consensus on a better name, then we can
change it before the release. Please see the 2nd discussion link below
for the discussion on the "Result Cache" name.
Author: David Rowley
Reviewed-by: Andy Fan, Justin Pryzby, Zhihong Yu
Tested-By: Konstantin Knizhnik
Discussion: https://postgr.es/m/CAApHDvrPcQyQdWERGYWx8J%2B2DLUNgXu%2BfOSbQ1UscxrunyXyrQ%40mail.gmail.com
Discussion: https://postgr.es/m/CAApHDvq=yQXr5kqhRviT2RhNKwToaWr9JAN5t+5_PzhuRJ3wvg@mail.gmail.com
Since a4d75c86b, some buildfarm members have been warning that
Assert(attnum <= MaxAttrNumber);
is useless if attnum is an AttrNumber. I'm not certain how plausible
it is that the value coming out of the bitmap could actually exceed
MaxAttrNumber, but we seem to have thought that that was possible back
in 7300a6995. Revert the intermediate variable to int so that we have
the same overflow protection as before.
Put the remote end's error message into the primary error string,
instead of relegating it to errdetail(). Although this could end up
being awkward if the remote sends us a really long error message,
it seems more in keeping with our message style guidelines, and more
helpful in situations where the errdetail could get dropped.
Peter Smith
Discussion: https://postgr.es/m/CAHut+Ps-Qv2yQceCwobQDP0aJOkfDzRFrOaR6+2Op2K=WHGeWg@mail.gmail.com
According to the comments, when an invalid or dropped column oid is passed
to has_column_privilege(), the intention has always been to return NULL.
However, when the caller had table level privilege the invalid/missing
column was never discovered, because table permissions were checked first.
Fix that by introducing extended versions of pg_attribute_acl(check|mask)
and pg_class_acl(check|mask) which take a new argument, is_missing. When
is_missing is NULL, the old behavior is preserved. But when is_missing is
passed by the caller, no ERROR is thrown for dropped or missing
columns/relations, and is_missing is flipped to true. This in turn allows
has_column_privilege to check for column privileges first, providing the
desired semantics.
Not backpatched since it is a user visible behavioral change with no previous
complaints, and the fix is a bit on the invasive side.
Author: Joe Conway
Reviewed-By: Tom Lane
Reported by: Ian Barwick
Discussion: https://postgr.es/m/flat/9b5f4311-157b-4164-7fe7-077b4fe8ed84%40joeconway.com
This patch makes two closely related sets of changes:
1. For UPDATE, the subplan of the ModifyTable node now only delivers
the new values of the changed columns (i.e., the expressions computed
in the query's SET clause) plus row identity information such as CTID.
ModifyTable must re-fetch the original tuple to merge in the old
values of any unchanged columns. The core advantage of this is that
the changed columns are uniform across all tables of an inherited or
partitioned target relation, whereas the other columns might not be.
A secondary advantage, when the UPDATE involves joins, is that less
data needs to pass through the plan tree. The disadvantage of course
is an extra fetch of each tuple to be updated. However, that seems to
be very nearly free in context; even worst-case tests don't show it to
add more than a couple percent to the total query cost. At some point
it might be interesting to combine the re-fetch with the tuple access
that ModifyTable must do anyway to mark the old tuple dead; but that
would require a good deal of refactoring and it seems it wouldn't buy
all that much, so this patch doesn't attempt it.
2. For inherited UPDATE/DELETE, instead of generating a separate
subplan for each target relation, we now generate a single subplan
that is just exactly like a SELECT's plan, then stick ModifyTable
on top of that. To let ModifyTable know which target relation a
given incoming row refers to, a tableoid junk column is added to
the row identity information. This gets rid of the horrid hack
that was inheritance_planner(), eliminating O(N^2) planning cost
and memory consumption in cases where there were many unprunable
target relations.
Point 2 of course requires point 1, so that there is a uniform
definition of the non-junk columns to be returned by the subplan.
We can't insist on uniform definition of the row identity junk
columns however, if we want to keep the ability to have both
plain and foreign tables in a partitioning hierarchy. Since
it wouldn't scale very far to have every child table have its
own row identity column, this patch includes provisions to merge
similar row identity columns into one column of the subplan result.
In particular, we can merge the whole-row Vars typically used as
row identity by FDWs into one column by pretending they are type
RECORD. (It's still okay for the actual composite Datums to be
labeled with the table's rowtype OID, though.)
There is more that can be done to file down residual inefficiencies
in this patch, but it seems to be committable now.
FDW authors should note several API changes:
* The argument list for AddForeignUpdateTargets() has changed, and so
has the method it must use for adding junk columns to the query. Call
add_row_identity_var() instead of manipulating the parse tree directly.
You might want to reconsider exactly what you're adding, too.
* PlanDirectModify() must now work a little harder to find the
ForeignScan plan node; if the foreign table is part of a partitioning
hierarchy then the ForeignScan might not be the direct child of
ModifyTable. See postgres_fdw for sample code.
* To check whether a relation is a target relation, it's no
longer sufficient to compare its relid to root->parse->resultRelation.
Instead, check it against all_result_relids or leaf_result_relids,
as appropriate.
Amit Langote and Tom Lane
Discussion: https://postgr.es/m/CA+HiwqHpHdqdDn48yCEhynnniahH78rwcrv1rEX65-fsZGBOLQ@mail.gmail.com
This allows something like
SELECT ... FROM t1 JOIN t2 USING (a, b, c) AS x
where x has the columns a, b, c and unlike a regular alias it does not
hide the range variables of the tables being joined t1 and t2.
Per SQL:2016 feature F404 "Range variable for common column names".
Reviewed-by: Vik Fearing <vik.fearing@2ndquadrant.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/flat/454638cf-d563-ab76-a585-2564428062af@2ndquadrant.com
This implements asynchronous execution, which runs multiple parts of a
non-parallel-aware Append concurrently rather than serially to improve
performance when possible. Currently, the only node type that can be
run concurrently is a ForeignScan that is an immediate child of such an
Append. In the case where such ForeignScans access data on different
remote servers, this would run those ForeignScans concurrently, and
overlap the remote operations to be performed simultaneously, so it'll
improve the performance especially when the operations involve
time-consuming ones such as remote join and remote aggregation.
We may extend this to other node types such as joins or aggregates over
ForeignScans in the future.
This also adds the support for postgres_fdw, which is enabled by the
table-level/server-level option "async_capable". The default is false.
Robert Haas, Kyotaro Horiguchi, Thomas Munro, and myself. This commit
is mostly based on the patch proposed by Robert Haas, but also uses
stuff from the patch proposed by Kyotaro Horiguchi and from the patch
proposed by Thomas Munro. Reviewed by Kyotaro Horiguchi, Konstantin
Knizhnik, Andrey Lepikhov, Movead Li, Thomas Munro, Justin Pryzby, and
others.
Discussion: https://postgr.es/m/CA%2BTgmoaXQEt4tZ03FtQhnzeDEMzBck%2BLrni0UWHVVgOTnA6C1w%40mail.gmail.com
Discussion: https://postgr.es/m/CA%2BhUKGLBRyu0rHrDCMC4%3DRn3252gogyp1SjOgG8SEKKZv%3DFwfQ%40mail.gmail.com
Discussion: https://postgr.es/m/20200228.170650.667613673625155850.horikyota.ntt%40gmail.com
ParseNamespaceItem had a wired-in assumption that p_rte->eref
describes the table and column aliases exposed by the nsitem. This
relaxes this by creating a separate p_names field in an nsitem. This
is mainly preparation for a patch for JOIN USING aliases, but it saves
one indirection in common code paths, so it's possibly a win on its
own.
Author: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/785329.1616455091@sss.pgh.pa.us
We always inserted a larger-than-fillfactor tuple into a newly-extended
page, even when existing pages were empty or contained nothing but an
unused line pointer. This was unnecessary relation extension. Start
tolerating page usage up to 1/8 the maximum space that could be taken up
by line pointers. This is somewhat arbitrary, but it should allow more
cases to reuse pages. This has no effect on tables with fillfactor=100
(the default).
John Naylor and Floris van Nee. Reviewed by Matthias van de Meent.
Reported by Floris van Nee.
Discussion: https://postgr.es/m/6e263217180649339720afe2176c50aa@opammb0562.comp.optiver.com
Whilst poking at nodeModifyTable.c, I chanced to notice that while
its calls to ExecBR*Triggers and ExecIR*Triggers are protected by
tests to see if there are any relevant triggers to fire, its calls
to ExecAR*Triggers are not; the latter functions do the equivalent
tests themselves. This seems possibly reasonable given the more
complex conditions involved, but what's less reasonable is that
the ExecAR* functions aren't careful to do no work when there is
no work to be done. ExecARInsertTriggers gets this right, but the
other two will both force creation of a slot that the query may
have no use for. ExecARUpdateTriggers additionally performed a
usually-useless ExecClearTuple() on that slot. This is probably
all pretty microscopic in real workloads, but a cycle shaved is a
cycle earned.
Here we add a new output parameter to estimate_num_groups() to allow it to
inform the caller of additional, possibly useful information about the
estimation.
The new output parameter is a struct that currently contains just a single
field with a set of flags. This was done rather than having the flags as
an output parameter to allow future fields to be added without having to
change the signature of the function at a later date when we want to pass
back further information that might not be suitable to store in the flags
field.
It seems reasonable that one day in the future that the planner would want
to know more about the estimation. For example, how many individual sets
of statistics was the estimation generated from? The planner may want to
take that into account if we ever want to consider risks as well as costs
when generating plans.
For now, there's only 1 flag we set in the flags field. This is to
indicate if the estimation fell back on using the hard-coded constants in
any part of the estimation. Callers may like to change their behavior if
this is set, and this gives them the ability to do so. Callers may pass
the flag pointer as NULL if they have no interest in obtaining any
additional information about the estimate.
We're not adding any actual usages of these flags here. Some follow-up
commits will make use of this feature. Additionally, we're also not
making any changes to add support for clauselist_selectivity() and
clauselist_selectivity_ext(). However, if this is required in the future
then the same struct being added here should be fine to use as a new
output argument for those functions too.
Author: David Rowley
Discussion: https://postgr.es/m/CAApHDvqQqpk=1W-G_ds7A9CsXX3BggWj_7okinzkLVhDubQzjA@mail.gmail.com
Along with gid, this provides a different way to identify the transaction.
The users that use xid in some way to prepare the transactions can use it
to filter prepare transactions. The later commands COMMIT PREPARED or
ROLLBACK PREPARED carries both identifiers, providing an output plugin the
choice of what to use.
Author: Markus Wanner
Reviewed-by: Vignesh C, Amit Kapila
Discussion: https://postgr.es/m/ee280000-7355-c4dc-e47b-2436e7be959c@enterprisedb.com
The design of the data structures which allow storage of the per-worker
memory during parallel seq scans were not ideal. The work done in
56788d215 required an additional data structure to allow workers to
remember the range of pages that had been allocated to them for
processing during a parallel seqscan. That commit added a void pointer
field to TableScanDescData to allow heapam to store the per-worker
allocation information. However putting the field there made very little
sense given that we have AM specific structs for that, e.g.
HeapScanDescData.
Here we remove the void pointer field from TableScanDescData and add a
dedicated field for this purpose to HeapScanDescData.
Previously we also allocated memory for this parallel per-worker data for
all scans, regardless if it was a parallel scan or not. This was just a
wasted allocation for non-parallel scans, so here we make the allocation
conditional on the scan being parallel.
Also, add previously missing pfree() to free the per-worker data in
heap_endscan().
Reported-by: Andres Freund
Reviewed-by: Andres Freund
Discussion: https://postgr.es/m/20210317023101.anvejcfotwka6gaa@alap3.anarazel.de
Currently we only recognize the Common Name (CN) of a certificate's
subject to be matched against the user name. Thus certificates with
subjects '/OU=eng/CN=fred' and '/OU=sales/CN=fred' will have the same
connection rights. This patch provides an option to match the whole
Distinguished Name (DN) instead of just the CN. On any hba line using
client certificate identity, there is an option 'clientname' which can
have values of 'DN' or 'CN'. The default is 'CN', the current procedure.
The DN is matched against the RFC2253 formatted DN, which looks like
'CN=fred,OU=eng'.
This facility of probably best used in conjunction with an ident map.
Discussion: https://postgr.es/m/92e70110-9273-d93c-5913-0bccb6562740@dunslane.net
Reviewed-By: Michael Paquier, Daniel Gustafsson, Jacob Champion
Here we aim to reduce duplicate work done by contain_volatile_functions()
by caching whether PathTargets and RestrictInfos contain any volatile
functions the first time contain_volatile_functions() is called for them.
Any future calls for these nodes just use the cached value rather than
going to the trouble of recursively checking the sub-node all over again.
Thanks to Tom Lane for the idea.
Any locations in the code which make changes to a PathTarget or
RestrictInfo which could change the outcome of the volatility check must
change the cached value back to VOLATILITY_UNKNOWN again.
contain_volatile_functions() is the only code in charge of setting the
cache value to either VOLATILITY_VOLATILE or VOLATILITY_NOVOLATILE.
Some existing code does benefit from this additional caching, however,
this change is mainly aimed at an upcoming patch that must check for
volatility during the join search. Repeated volatility checks in that
case can become very expensive when the join search contains more than a
few relations.
Author: David Rowley
Discussion: https://postgr.es/m/3795226.1614059027@sss.pgh.pa.us
Allow defining extended statistics on expressions, not just just on
simple column references. With this commit, expressions are supported
by all existing extended statistics kinds, improving the same types of
estimates. A simple example may look like this:
CREATE TABLE t (a int);
CREATE STATISTICS s ON mod(a,10), mod(a,20) FROM t;
ANALYZE t;
The collected statistics are useful e.g. to estimate queries with those
expressions in WHERE or GROUP BY clauses:
SELECT * FROM t WHERE mod(a,10) = 0 AND mod(a,20) = 0;
SELECT 1 FROM t GROUP BY mod(a,10), mod(a,20);
This introduces new internal statistics kind 'e' (expressions) which is
built automatically when the statistics object definition includes any
expressions. This represents single-expression statistics, as if there
was an expression index (but without the index maintenance overhead).
The statistics is stored in pg_statistics_ext_data as an array of
composite types, which is possible thanks to 79f6a942bd.
CREATE STATISTICS allows building statistics on a single expression, in
which case in which case it's not possible to specify statistics kinds.
A new system view pg_stats_ext_exprs can be used to display expression
statistics, similarly to pg_stats and pg_stats_ext views.
ALTER TABLE ... ALTER COLUMN ... TYPE now treats indexes the same way it
treats indexes, i.e. it drops and recreates the statistics. This means
all statistics are reset, and we no longer try to preserve at least the
functional dependencies. This should not be a major issue in practice,
as the functional dependencies actually rely on per-column statistics,
which were always reset anyway.
Author: Tomas Vondra
Reviewed-by: Justin Pryzby, Dean Rasheed, Zhihong Yu
Discussion: https://postgr.es/m/ad7891d2-e90c-b446-9fe2-7419143847d7%40enterprisedb.com
When estimating the number of groups using extended statistics, the code
was discarding information about system attributes. This led to strange
situation that
SELECT 1 FROM t GROUP BY ctid;
could have produced higher estimate (equal to pg_class.reltuples) than
SELECT 1 FROM t GROUP BY a, b, ctid;
with extended statistics on (a,b). Fixed by retaining information about
the system attribute.
Backpatch all the way to 10, where extended statistics were introduced.
Author: Tomas Vondra
Backpatch-through: 10
Membership consists, implicitly, of the current database owner. Expect
use in template databases. Once pg_database_owner has rights within a
template, each owner of a database instantiated from that template will
exercise those rights.
Reviewed by John Naylor.
Discussion: https://postgr.es/m/20201228043148.GA1053024@rfd.leadboat.com
The deserialization failed to ensure correct alignment, as it assumed it
can simply point into the serialized value. The serialization however
ignores alignment and copies just the significant bytes in order to make
the result as small as possible. This caused failures on systems that
are sensitive to mialigned addresses, like sparc, or with address
sanitizer enabled.
Fixed by copying the serialized data to ensure proper alignment. While
at it, fix an issue with serialization on big endian machines, using the
same store_att_byval/fetch_att trick as extended statistics.
Discussion: https://postgr.es/0c8c3304-d3dd-5e29-d5ac-b50589a23c8c%40enterprisedb.com
Adds BRIN opclasses similar to the existing minmax, except that instead
of summarizing the page range into a single [min,max] range, the summary
consists of multiple ranges and/or points, allowing gaps. This allows
more efficient handling of data with poor correlation to physical
location within the table and/or outlier values, for which the regular
minmax opclassed tend to work poorly.
It's possible to specify the number of values kept for each page range,
either as a single point or an interval boundary.
CREATE TABLE t (a int);
CREATE INDEX ON t
USING brin (a int4_minmax_multi_ops(values_per_range=16));
When building the summary, the values are combined into intervals with
the goal to minimize the "covering" (sum of interval lengths), using a
support procedure computing distance between two values.
Bump catversion, due to various catalog changes.
Author: Tomas Vondra <tomas.vondra@postgresql.org>
Reviewed-by: Alvaro Herrera <alvherre@alvh.no-ip.org>
Reviewed-by: Alexander Korotkov <aekorotkov@gmail.com>
Reviewed-by: Sokolov Yura <y.sokolov@postgrespro.ru>
Reviewed-by: John Naylor <john.naylor@enterprisedb.com>
Discussion: https://postgr.es/m/c1138ead-7668-f0e1-0638-c3be3237e812@2ndquadrant.com
Discussion: https://postgr.es/m/5d78b774-7e9c-c94e-12cf-fef51cc89b1a%402ndquadrant.com
Adds a BRIN opclass using a Bloom filter to summarize the range. Indexes
using the new opclasses allow only equality queries (similar to hash
indexes), but that works fine for data like UUID, MAC addresses etc. for
which range queries are not very common. This also means the indexes
work for data that is not well correlated to physical location within
the table, or perhaps even entirely random (which is a common issue with
existing BRIN minmax opclasses).
It's possible to specify opclass parameters with the usual Bloom filter
parameters, i.e. the desired false-positive rate and the expected number
of distinct values per page range.
CREATE TABLE t (a int);
CREATE INDEX ON t
USING brin (a int4_bloom_ops(false_positive_rate = 0.05,
n_distinct_per_range = 100));
The opclasses do not operate on the indexed values directly, but compute
a 32-bit hash first, and the Bloom filter is built on the hash value.
Collisions should not be a huge issue though, as the number of distinct
values in a page ranges is usually fairly small.
Bump catversion, due to various catalog changes.
Author: Tomas Vondra <tomas.vondra@postgresql.org>
Reviewed-by: Alvaro Herrera <alvherre@alvh.no-ip.org>
Reviewed-by: Alexander Korotkov <aekorotkov@gmail.com>
Reviewed-by: Sokolov Yura <y.sokolov@postgrespro.ru>
Reviewed-by: Nico Williams <nico@cryptonector.com>
Reviewed-by: John Naylor <john.naylor@enterprisedb.com>
Discussion: https://postgr.es/m/c1138ead-7668-f0e1-0638-c3be3237e812@2ndquadrant.com
Discussion: https://postgr.es/m/5d78b774-7e9c-c94e-12cf-fef51cc89b1a%402ndquadrant.com
Commit a1c649d889 changed the signature of the BRIN consistent function
by adding a new required parameter. Treating the parameter as optional,
which would make the change backwards incompatibile, was rejected with
the justification that there are few out-of-core extensions, so it's not
worth adding making the code more complex, and it's better to deal with
that in the extension.
But after further thought, that would be rather problematic, because
pg_upgrade simply dumps catalog contents and the same version of an
extension needs to work on both PostgreSQL versions. Supporting both
variants of the consistent function (with 3 or 4 arguments) makes that
possible.
The signature is not the only thing that changed, as commit 72ccf55cb9
moved handling of IS [NOT] NULL keys from the support procedures. But
this change is backward compatible - handling the keys in exension is
unnecessary, but harmless. The consistent function will do a bit of
unnecessary work, but it should be very cheap.
This also undoes most of the changes to the existing opclasses (minmax
and inclusion), making them use the old signature again. This should
make backpatching simpler.
Catversion bump, because of changes in pg_amproc.
Author: Tomas Vondra <tomas.vondra@postgresql.org>
Author: Nikita Glukhov <n.gluhov@postgrespro.ru>
Reviewed-by: Mark Dilger <hornschnorter@gmail.com>
Reviewed-by: Alexander Korotkov <aekorotkov@gmail.com>
Reviewed-by: Masahiko Sawada <masahiko.sawada@enterprisedb.com>
Reviewed-by: John Naylor <john.naylor@enterprisedb.com>
Discussion: https://postgr.es/m/c1138ead-7668-f0e1-0638-c3be3237e812@2ndquadrant.com
Allow a partition be detached from its partitioned table without
blocking concurrent queries, by running in two transactions and only
requiring ShareUpdateExclusive in the partitioned table.
Because it runs in two transactions, it cannot be used in a transaction
block. This is the main reason to use dedicated syntax: so that users
can choose to use the original mode if they need it. But also, it
doesn't work when a default partition exists (because an exclusive lock
would still need to be obtained on it, in order to change its partition
constraint.)
In case the second transaction is cancelled or a crash occurs, there's
ALTER TABLE .. DETACH PARTITION .. FINALIZE, which executes the final
steps.
The main trick to make this work is the addition of column
pg_inherits.inhdetachpending, initially false; can only be set true in
the first part of this command. Once that is committed, concurrent
transactions that use a PartitionDirectory will include or ignore
partitions so marked: in optimizer they are ignored if the row is marked
committed for the snapshot; in executor they are always included. As a
result, and because of the way PartitionDirectory caches partition
descriptors, queries that were planned before the detach will see the
rows in the detached partition and queries that are planned after the
detach, won't.
A CHECK constraint is created that duplicates the partition constraint.
This is probably not strictly necessary, and some users will prefer to
remove it afterwards, but if the partition is re-attached to a
partitioned table, the constraint needn't be rechecked.
Author: Álvaro Herrera <alvherre@alvh.no-ip.org>
Reviewed-by: Amit Langote <amitlangote09@gmail.com>
Reviewed-by: Justin Pryzby <pryzby@telsasoft.com>
Discussion: https://postgr.es/m/20200803234854.GA24158@alvherre.pgsql
Struct AlteredRelationInfo gains a new Relation member, to be used only
by Phase 2 (ATRewriteCatalogs); this allows ATExecCmd() subroutines open
and close the relation internally.
A future commit will use this facility to implement an ALTER TABLE
subcommand that closes and reopens the relation across transaction
boundaries.
(It is possible to keep the relation open past phase 2 to be used by
phase 3 instead of having to reopen it that point, but there are some
minor complications with that; it's not clear that there is much to be
won from doing that, though.)
Author: Álvaro Herrera <alvherre@alvh.no-ip.org>
Discussion: https://postgr.es/m/20200803234854.GA24158@alvherre.pgsql
I introduced this duplicate code in commit 8b08f7d482 for no good
reason. Remove it, and backpatch to 11 where it was introduced.
Author: Álvaro Herrera <alvherre@alvh.no-ip.org>
Previously the WAL replay of COMMIT_TS_SETTS record called
TransactionTreeSetCommitTsData() with the argument write_xlog=true,
which generated and wrote new COMMIT_TS_SETTS record.
This should not be acceptable because it's during recovery.
This commit fixes the WAL replay of COMMIT_TS_SETTS record
so that it calls TransactionTreeSetCommitTsData() with write_xlog=false
and doesn't generate new WAL during recovery.
Back-patch to all supported branches.
Reported-by: lx zou <zoulx1982@163.com>
Author: Fujii Masao
Reviewed-by: Alvaro Herrera
Discussion: https://postgr.es/m/16931-620d0f2fdc6108f1@postgresql.org
Previously when an archive recovery or a standby was starting and
reached the consistent recovery state but hot_standby was configured
to off, the error message when a client connectted was "the database
system is starting up", which was needless confusing and not really
all that accurate either.
This commit improves the connection denied error message during
recovery, as follows, so that the users immediately know that their
servers are configured to deny those connections.
- If hot_standby is disabled, the error message "the database system
is not accepting connections" and the detail message "Hot standby
mode is disabled." are output when clients connect while an archive
recovery or a standby is running.
- If hot_standby is enabled, the error message "the database system
is not yet accepting connections" and the detail message
"Consistent recovery state has not been yet reached." are output
when clients connect until the consistent recovery state is reached
and postmaster starts accepting read only connections.
This commit doesn't change the connection denied error message of
"the database system is starting up" during normal server startup and
crash recovery. Because it's still suitable for those situations.
Author: James Coleman
Reviewed-by: Alvaro Herrera, Andres Freund, David Zhang, Tom Lane, Fujii Masao
Discussion: https://postgr.es/m/CAAaqYe8h5ES_B=F_zDT+Nj9XU7YEwNhKhHA2RE4CFhAQ93hfig@mail.gmail.com
Common recommendations are that the checkpoint should be spread out as
much as possible, provided we avoid having it take too long. This
change updates the default to 0.9 (from 0.5) to match that
recommendation.
There was some debate about possibly removing the option entirely but it
seems there may be some corner-cases where having it set much lower to
try to force the checkpoint to be as fast as possible could result in
fewer periods of time of reduced performance due to kernel flushing.
General agreement is that the "spread more" is the preferred approach
though and those who need to tune away from that value are much less
common.
Reviewed-By: Michael Paquier, Peter Eisentraut, Tom Lane, David Steele,
Nathan Bossart
Discussion: https://postgr.es/m/20201207175329.GM16415%40tamriel.snowman.net
Change the default_toast_compression GUC to be an enum rather than
a string. Earlier, uncommitted versions of the patch supported using
CREATE ACCESS METHOD to add new compression methods to a running
system, but that idea was dropped before commit. So, we can simplify
the GUC handling as well, which has the nice side effect of improving
the error messages.
While updating the documentation to reflect the new GUC type, also
move it back to the right place in the list. I moved this while
revising what became commit 24f0e395ac,
but apparently the intended ordering is "alphabetical" rather than
"whatever Robert thinks looks nice."
Rejigger things to avoid having access/toast_compression.h depend on
utils/guc.h, so that we don't end up with every file that includes
it also depending on something largely unrelated. Move a few
inline functions back into the C source file partly to help reduce
dependencies and partly just to avoid clutter. A few very minor
cosmetic fixes.
Original patch by Justin Pryzby, but very heavily edited by me,
and reverse reviewed by him and also reviewed by by Tom Lane.
Discussion: http://postgr.es/m/CA+TgmoYp=GT_ztUCeZg2i4hkHAQv8o=-nVJ1-TKWTG1zQOmOpg@mail.gmail.com
Similar to date_trunc, but allows binning by an arbitrary interval
rather than just full units.
Author: John Naylor <john.naylor@enterprisedb.com>
Reviewed-by: David Fetter <david@fetter.org>
Reviewed-by: Isaac Morland <isaac.morland@gmail.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Artur Zakirov <zaartur@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/CACPNZCt4buQFRgy6DyjuZS-2aPDpccRkrJBmgUfwYc1KiaXYxg@mail.gmail.com
To allow inserts in parallel-mode this feature has to ensure that all the
constraints, triggers, etc. are parallel-safe for the partition hierarchy
which is costly and we need to find a better way to do that. Additionally,
we could have used existing cached information in some cases like indexes,
domains, etc. to determine the parallel-safety.
List of commits reverted, in reverse chronological order:
ed62d3737c Doc: Update description for parallel insert reloption.
c8f78b6161 Add a new GUC and a reloption to enable inserts in parallel-mode.
c5be48f092 Improve FK trigger parallel-safety check added by 05c8482f7f.
e2cda3c20a Fix use of relcache TriggerDesc field introduced by commit 05c8482f7f.
e4e87a32cc Fix valgrind issue in commit 05c8482f7f.
05c8482f7f Enable parallel SELECT for "INSERT INTO ... SELECT ...".
Discussion: https://postgr.es/m/E1lMiB9-0001c3-SY@gemulon.postgresql.org
Commit de829ddf23 added wait event WalrcvExit. But its name is not
consistent with other wait events like WalReceiverMain or
WalReceiverWaitStart, etc. So this commit renames WalrcvExit to
WalReceiverExit.
Author: Fujii Masao
Reviewed-by: Thomas Munro
Discussion: https://postgr.es/m/cced9995-8fa2-7b22-9d91-3f22a2b8c23c@oss.nttdata.com
GetNewOidWithIndex() generates a new OID one by one until it finds
one not in the relation. If there are very long runs of consecutive
existing OIDs, GetNewOidWithIndex() needs to iterate many times
in the loop to find unused OID. Since TOAST table can have a large
number of entries and there can be such long runs of OIDs, there is
the case where it takes so many iterations to find new OID not in
TOAST table. Furthermore if all (i.e., 2^32) OIDs are already used,
GetNewOidWithIndex() enters something like busy loop and repeats
the iterations until at least one OID is marked as unused.
There are some reported troubles caused by a large number of
iterations in GetNewOidWithIndex(). For example, when inserting
a billion of records into the table, all the backends doing that
insertion operation got hang with 100% CPU usage at some point.
Previously there was no easy way to detect that GetNewOidWithIndex()
failed to find unused OID many times. So, for example, gdb full
backtrace of hanged backends needed to be taken, in order to
investigate that trouble. This is inconvenient and may not be
available in some production environments.
To provide easy way for that, this commit makes GetNewOidWithIndex()
log that it iterates more than GETNEWOID_LOG_THRESHOLD but have
not yet found OID unused in the relation. Also this commit makes
it repeat logging with exponentially increasing intervals until
it iterates more than GETNEWOID_LOG_MAX_INTERVAL, and makes it
finally repeat logging every GETNEWOID_LOG_MAX_INTERVAL unless
an unused OID is found. Those macro variables are used not to
fill up the server log with the similar messages.
In the discusion at pgsql-hackers, there was another idea to report
the lots of iterations in GetNewOidWithIndex() via wait event.
But since GetNewOidWithIndex() traverses indexes to find unused
OID and which will do I/O, acquire locks, etc, which will overwrite
the wait event and reset it to nothing once done. So that idea
doesn't work well, and we didn't adopt it.
Author: Tomohiro Hiramitsu
Reviewed-by: Tatsuhito Kasahara, Kyotaro Horiguchi, Tom Lane, Fujii Masao
Discussion: https://postgr.es/m/16722-93043fb459a41073@postgresql.org
When resolving types during catalog bootstrap, try to reload the pg_type
contents if a type is not found. That allows catalogs to contain
composite types, e.g. row types for other catalogs.
Author: Justin Pryzby
Reviewed-by: Dean Rasheed, Tomas Vondra
Discussion: https://postgr.es/m/ad7891d2-e90c-b446-9fe2-7419143847d7%40enterprisedb.com
It's a bit easier and more convenient to free and reload a List,
compared to a plain array. This will be helpful when allowing catalogs
to contain composite types.
Author: Justin Pryzby
Reviewed-by: Dean Rasheed, Tomas Vondra
Discussion: https://postgr.es/m/ad7891d2-e90c-b446-9fe2-7419143847d7%40enterprisedb.com
Teach nbtree VACUUM to press on with vacuuming in the event of a page
deletion attempt that fails to "re-find" a downlink for its child/target
page.
There is no good reason to treat this as an irrecoverable error. But
there is a good reason not to: pressing on at this point removes any
question of VACUUM not making progress solely due to misbehavior from
user-defined operator class code.
Discussion: https://postgr.es/m/CAH2-Wzma5G9CTtMjbrXTwOym+U=aWg-R7=-htySuztgoJLvZXg@mail.gmail.com
end_heap_rewrite was not careful to ensure that the target relation
is open at the smgr level before performing its final smgrimmedsync.
In ordinary cases this is no problem, because it would have been
opened earlier during the rewrite. However a crash can be reproduced
by re-clustering an empty table with CLOBBER_CACHE_ALWAYS enabled.
Although that exact scenario does not crash in v13, I think that's
a chance result of unrelated planner changes, and the problem is
likely still reachable with other test cases. The true proximate
cause of this failure is commit c6b92041d, which replaced a call to
heap_sync (which was careful about opening smgr) with a direct call
to smgrimmedsync. Hence, back-patch to v13.
Amul Sul, per report from Neha Sharma; cosmetic changes
and test case by me.
Discussion: https://postgr.es/m/CANiYTQsU7yMFpQYnv=BrcRVqK_3U3mtAzAsJCaqtzsDHfsUbdQ@mail.gmail.com
This function for bit and bytea counts the set bits in the bit or byte
string. Internally, we use the existing popcount functionality.
For the name, after some discussion, we settled on bit_count, which
also exists with this meaning in MySQL, Java, and Python.
Author: David Fetter <david@fetter.org>
Discussion: https://www.postgresql.org/message-id/flat/20201230105535.GJ13234@fetter.org
Once a relation's autovacuum is completed, the logs include more
information about this relation state if the threshold of
log_autovacuum_min_duration (or its relation option) is reached, with
for example contents about the statistics of the VACUUM operation for
the relation, WAL and system usage.
This commit adds more information about the statistics of the relation's
indexes, with one line of logs generated for each index. The index
stats were already calculated, but not printed in the context of
autovacuum yet. While on it, some refactoring is done to keep track of
the index statistics directly within LVRelStats, simplifying some
routines related to parallel VACUUMs.
Author: Masahiko Sawada
Reviewed-by: Michael Paquier, Euler Taveira
Discussion: https://postgr.es/m/CAD21AoAy6SxHiTivh5yAPJSUE4S=QRPpSZUdafOSz0R+fRcM6Q@mail.gmail.com
A couple error messages and comments used 'statistic kind', not the
correct 'statistics kind'. Fix and backpatch all the way back to 10,
where extended statistics were introduced.
Backpatch-through: 10
Previously the type of this wait event was Client. But while this
wait event is being reported, walreceiver process is waiting for
the startup process to set initial data for streaming replication.
It's not waiting for any activity on a socket connected to a user
application or walsender. So this commit changes the type for
WalReceiverWaitStart wait event to IPC.
Author: Fujii Masao
Reviewed-by: Kyotaro Horiguchi
Discussion: https://postgr.es/m/cdacc27c-37ff-f1a4-20e2-ce19933abfcc@oss.nttdata.com
Previously, to check relation permanence, the Relation's Form_pg_class
structure member relpersistence was compared to the value
RELPERSISTENCE_PERMANENT ("p"). This commit adds the macro
RelationIsPermanent() and is used in appropirate places to simplify the
code. This matches other RelationIs* macros.
This macro will be used in more places in future cluster file encryption
patches.
Discussion: https://postgr.es/m/20210318153134.GH20766@tamriel.snowman.net
The bringetbitmap function allocates memory for various purposes, which
may be quite expensive, depending on the number of scan keys. Instead of
allocating them separately, allocate one bit chunk of memory an carve it
into smaller pieces as needed - all the pieces have the same lifespan,
and it saves quite a bit of CPU and memory overhead.
Author: Tomas Vondra <tomas.vondra@postgresql.org>
Reviewed-by: Alvaro Herrera <alvherre@alvh.no-ip.org>
Reviewed-by: Mark Dilger <hornschnorter@gmail.com>
Reviewed-by: Alexander Korotkov <aekorotkov@gmail.com>
Reviewed-by: Masahiko Sawada <masahiko.sawada@enterprisedb.com>
Reviewed-by: John Naylor <john.naylor@enterprisedb.com>
Discussion: https://postgr.es/m/c1138ead-7668-f0e1-0638-c3be3237e812@2ndquadrant.com
The handling of IS [NOT] NULL clauses is independent of an opclass, and
most of the code was exactly the same in both minmax and inclusion. So
instead move the code from support procedures to the AM.
This simplifies the code - especially the support procedures - quite a
bit, as they don't need to care about NULL values and flags at all. It
also means the IS [NOT] NULL clauses can be evaluated without invoking
the support procedure.
Author: Tomas Vondra <tomas.vondra@postgresql.org>
Author: Nikita Glukhov <n.gluhov@postgrespro.ru>
Reviewed-by: Nikita Glukhov <n.gluhov@postgrespro.ru>
Reviewed-by: Mark Dilger <hornschnorter@gmail.com>
Reviewed-by: Alexander Korotkov <aekorotkov@gmail.com>
Reviewed-by: Masahiko Sawada <masahiko.sawada@enterprisedb.com>
Reviewed-by: John Naylor <john.naylor@enterprisedb.com>
Discussion: https://postgr.es/m/c1138ead-7668-f0e1-0638-c3be3237e812@2ndquadrant.com
This commit changes how we pass scan keys to BRIN consistent function.
Instead of passing them one by one, we now pass all scan keys for a
given attribute at once. That makes the consistent function a bit more
complex, as it has to loop through the keys, but it does allow more
elaborate opclasses that can use multiple keys to eliminate ranges much
more effectively.
The existing BRIN opclasses (minmax, inclusion) don't really benefit
from this change. The primary purpose is to allow future opclases to
benefit from seeing all keys at once.
This does change the BRIN API, because the signature of the consistent
function changes (a new parameter with number of scan keys). So this
breaks existing opclasses, and will require supporting two variants of
the code for different PostgreSQL versions. We've considered supporting
two variants of the consistent, but we've decided not to do that.
Firstly, there's another patch that moves handling of NULL values from
the opclass, which means the opclasses need to be updated anyway.
Secondly, we're not aware of any out-of-core BRIN opclasses, so it does
not seem worth the extra complexity.
Bump catversion, because of pg_proc changes.
Author: Tomas Vondra <tomas.vondra@postgresql.org>
Reviewed-by: Alvaro Herrera <alvherre@alvh.no-ip.org>
Reviewed-by: Mark Dilger <hornschnorter@gmail.com>
Reviewed-by: Alexander Korotkov <aekorotkov@gmail.com>
Reviewed-by: John Naylor <john.naylor@enterprisedb.com>
Reviewed-by: Nikita Glukhov <n.gluhov@postgrespro.ru>
Discussion: https://postgr.es/m/c1138ead-7668-f0e1-0638-c3be3237e812@2ndquadrant.com
Until now the bsearch_arg function was used only in extended statistics
code, so it was defined in that code. But we already have qsort_arg in
src/port, so let's move it next to it.
substring(), and perhaps other callers, isn't careful to pass a
slice length that is no more than the datum's true size. Since
toast_decompress_datum_slice's children will palloc the requested
slice length, this can waste memory. Also, close study of the liblz4
documentation suggests that it is dependent on the caller to not ask
for more than the correct amount of decompressed data; this squares
with observed misbehavior with liblz4 1.8.3. Avoid these problems
by switching to the normal full-decompression code path if the
slice request is >= datum's decompressed size.
Tom Lane and Dilip Kumar
Discussion: https://postgr.es/m/507597.1616370729@sss.pgh.pa.us
The authors of bbe0a81db hadn't quite got the idea that macros named
like SOMETHING_4B_C were only meant for internal endianness-related
details in postgres.h. Choose more legible names for macros that are
intended to be used elsewhere. Rearrange postgres.h a bit to clarify
the separation between those internal macros and ones intended for
wider use.
Also, avoid using the term "rawsize" for true decompressed size;
we've used "extsize" for that, because "rawsize" generally denotes
total Datum size including header. This choice seemed particularly
unfortunate in tests that were comparing one of these meanings to
the other.
This patch includes a couple of not-purely-cosmetic changes: be
sure that the shifts aligning compression methods are unsigned
(not critical today, but will be when compression method 2 exists),
and fix broken definition of VARATT_EXTERNAL_GET_COMPRESSION (now
VARATT_EXTERNAL_GET_COMPRESS_METHOD), whose callers worked only
accidentally.
Discussion: https://postgr.es/m/574197.1616428079@sss.pgh.pa.us
This commit is mostly a revert of aaa3aed, that switched the routine
doing the internal renaming of recycled WAL segments to use on Windows a
combination of CreateHardLinkA() plus unlink() instead of rename(). As
reported by several users of Postgres 13, this is causing concurrency
issues when manipulating WAL segments, mostly in the shape of the
following error:
LOG: could not rename file "pg_wal/000000XX000000YY000000ZZ":
Permission denied
This moves back to a logic where a single rename() (well, pgrename() for
Windows) is used. This issue has proved to be hard to hit when I tested
it, facing it only once with an archive_command that was not able to do
its work, so it is environment-sensitive. The reporters of this issue
have been able to confirm that the situation improved once we switched
back to a single rename(). In order to check things, I have provided to
the reporters a patched build based on 13.2 with aaa3aed reverted, to
test if the error goes away, and an unpatched build of 13.2 to test if
the error still showed up (just to make sure that I did not mess up my
build process).
Extra thanks to Fujii Masao for pointing out what looked like the
culprit commit, and to all the reporters for taking the time to test
what I have sent them.
Reported-by: Andrus, Guy Burgess, Yaroslav Pashinsky, Thomas Trenz
Reviewed-by: Tom Lane, Andres Freund
Discussion: https://postgr.es/m/3861ff1e-0923-7838-e826-094cc9bef737@hot.ee
Discussion: https://postgr.es/m/16874-c3eecd319e36a2bf@postgresql.org
Discussion: https://postgr.es/m/095ccf8d-7f58-d928-427c-b17ace23cae6@burgess.co.nz
Discussion: https://postgr.es/m/16927-67c570d968c99567%40postgresql.org
Discussion: https://postgr.es/m/YFBcRbnBiPdGZvfW@paquier.xyz
Backpatch-through: 13
Any transactions found as still prepared by a checkpoint have their
state data read from the WAL records generated by PREPARE TRANSACTION
before being moved into their new location within pg_twophase/. While
reading such records, the WAL reader uses the callback
read_local_xlog_page() to read a page, that is shared across various
parts of the system. This callback, since 1148e22a, has introduced an
update of ThisTimeLineID when reading a record while in recovery, which
is potentially helpful in the context of cascading WAL senders.
This update of ThisTimeLineID interacts badly with the checkpointer if a
promotion happens while some 2PC data is read from its record, as, by
changing ThisTimeLineID, any follow-up WAL records would be written to
an timeline older than the promoted one. This results in consistency
issues. For instance, a subsequent server restart would cause a failure
in finding a valid checkpoint record, resulting in a PANIC, for
instance.
This commit changes the code reading the 2PC data to reset the timeline
once the 2PC record has been read, to prevent messing up with the static
state of the checkpointer. It would be tempting to do the same thing
directly in read_local_xlog_page(). However, based on the discussion
that has led to 1148e22a, users may rely on the updates of
ThisTimeLineID when a WAL record page is read in recovery, so changing
this callback could break some cases that are working currently.
A TAP test reproducing the issue is added, relying on a PITR to
precisely trigger a promotion with a prepared transaction still
tracked.
Per discussion with Heikki Linnakangas, Kyotaro Horiguchi, Fujii Masao
and myself.
Author: Soumyadeep Chakraborty, Jimmy Yih, Kevin Yeap
Discussion: https://postgr.es/m/CAE-ML+_EjH_fzfq1F3RJ1=XaaNG=-Jz-i3JqkNhXiLAsM3z-Ew@mail.gmail.com
Backpatch-through: 10
It's not okay to scribble directly on a syscache entry.
Nor to continue accessing said entry after releasing it.
Also get rid of not-used local variables.
Per valgrind testing.
Maintain a simple array of metadata about pages that were deleted during
nbtree VACUUM's current btvacuumscan() call. Use this metadata at the
end of btvacuumscan() to attempt to place newly deleted pages in the FSM
without further delay. It might not yet be safe to place any of the
pages in the FSM by then (they may not be deemed recyclable), but we
have little to lose and plenty to gain by trying. In practice there is
a very good chance that this will work out when vacuuming larger
indexes, where scanning the index naturally takes quite a while.
This commit doesn't change the page recycling invariants; it merely
improves the efficiency of page recycling within the confines of the
existing design. Recycle safety is a part of nbtree's implementation of
what Lanin & Shasha call "the drain technique". The design happens to
use transaction IDs (they're stored in deleted pages), but that in
itself doesn't align the cutoff for recycle safety to any of the
XID-based cutoffs used by VACUUM (e.g., OldestXmin). All that matters
is whether or not _other_ backends might be able to observe various
inconsistencies in the tree structure (that they cannot just detect and
recover from by moving right). Recycle safety is purely a question of
maintaining the consistency (or the apparent consistency) of a physical
data structure.
Note that running a simple serial test case involving a large range
DELETE followed by a VACUUM VERBOSE will probably show that any newly
deleted nbtree pages are not yet reusable/recyclable. This is expected
in the absence of even one concurrent XID assignment. It is an old
implementation restriction. In practice it's unlikely to be the thing
that makes recycling remain unsafe, at least with larger indexes, where
recycling newly deleted pages during the same VACUUM actually matters.
An important high-level goal of this commit (as well as related recent
commits e5d8a999 and 9f3665fb) is to make expensive deferred cleanup
operations in index AMs rare in general. If index vacuuming frequently
depends on the next VACUUM operation finishing off work that the current
operation started, then the general behavior of index vacuuming is hard
to predict. This is relevant to ongoing work that adds a vacuumlazy.c
mechanism to skip index vacuuming in certain cases. Anything that makes
the real world behavior of index vacuuming simpler and more linear will
also make top-down modeling in vacuumlazy.c more robust.
Author: Peter Geoghegan <pg@bowt.ie>
Reviewed-By: Masahiko Sawada <sawada.mshk@gmail.com>
Discussion: https://postgr.es/m/CAH2-Wzk76_P=67iUscb1UN44-gyZL-KgpsXbSxq_bdcMa7Q+wQ@mail.gmail.com
Compilers that don't understand that elog(ERROR) doesn't return
issued warnings here. In the cases in libpq_pipeline.c, we were
not exactly helping things by failing to mark pg_fatal() as noreturn.
Per buildfarm.
When compressing the BRIN summary, we can't simply use the compression
method from the indexed attribute. The summary may use a different data
type, e.g. fixed-length attribute may have varlena summary, leading to
compression failures. For the built-in BRIN opclasses this happens to
work, because the summary uses the same data type as the attribute.
When the data types match, we can inherit use the compression method
specified for the attribute (it's copied into the index descriptor).
Otherwise we don't have much choice and have to use the default one.
Author: Tomas Vondra
Reviewed-by: Justin Pryzby <pryzby@telsasoft.com>
Discussion: https://postgr.es/m/e0367f27-392c-321a-7411-a58e1a7e4817%40enterprisedb.com
While back-patching e0e569e1d, I noted that there were some other
places where we ought to be applying DH_free(); namely, where we
load some DH parameters from a file and then reject them as not
being sufficiently secure. While it seems really unlikely that
anybody would hit these code paths in production, let alone do
so repeatedly, let's fix it for consistency.
Back-patch to v10 where this code was introduced.
Discussion: https://postgr.es/m/16160-18367e56e9a28264@postgresql.org
RestoreGUCState applied InitializeOneGUCOption to already-live
GUC entries, causing any malloc'd subsidiary data to be forgotten.
We do want the effect of resetting the GUC to its compiled-in
default, and InitializeOneGUCOption seems like the best way to do
that, so add code to free any existing subsidiary data beforehand.
The interaction between can_skip_gucvar, SerializeGUCState, and
RestoreGUCState is way more subtle than their opaque comments
would suggest to an unwary reader. Rewrite and enlarge the
comments to try to make it clearer what's happening.
Remove a long-obsolete assertion in read_nondefault_variables: the
behavior of set_config_option hasn't depended on IsInitProcessingMode
since f5d9698a8 installed a better way of controlling it.
Although this is fixing a clear memory leak, the leak is quite unlikely
to involve any large amount of data, and it can only happen once in the
lifetime of a worker process. So it seems unnecessary to take any
risk of back-patching.
Discussion: https://postgr.es/m/4105247.1616174862@sss.pgh.pa.us
Since commit 2ce439f3 we have opened every file in the data directory
and called fsync() at the start of crash recovery. This can be very
slow if there are many files, leading to field complaints of systems
taking minutes or even hours to begin crash recovery.
Provide an alternative method, for Linux only, where we call syncfs() on
every possibly different filesystem under the data directory. This is
equivalent, but avoids faulting in potentially many inodes from
potentially slow storage.
The new mode comes with some caveats, described in the documentation, so
the default value for the new setting is "fsync", preserving the older
behavior.
Reported-by: Michael Brown <michael.brown@discourse.org>
Reviewed-by: Fujii Masao <masao.fujii@oss.nttdata.com>
Reviewed-by: Paul Guo <guopa@vmware.com>
Reviewed-by: Bruce Momjian <bruce@momjian.us>
Reviewed-by: Justin Pryzby <pryzby@telsasoft.com>
Reviewed-by: David Steele <david@pgmasters.net>
Discussion: https://postgr.es/m/11bc2bb7-ecb5-3ad0-b39f-df632734cd81%40discourse.org
Discussion: https://postgr.es/m/CAEET0ZHGnbXmi8yF3ywsDZvb3m9CbdsGZgfTXscQ6agcbzcZAw%40mail.gmail.com
The function added in be45be9c33 is comparing integer lists (IntList) by
length and contents, but there were two bugs. Firstly, it used intVal()
to extract the value, but that's for Value nodes, not for extracting int
values from IntList. Secondly, it called it directly on the ListCell,
without doing lfirst(). So just do lfirst_int() instead.
Interestingly enough, this did not cause any crashes on the buildfarm,
but valgrind rightfully complained about it.
Discussion: https://postgr.es/m/bf3805a8-d7d1-ae61-fece-761b7ff41ecc@postgresfriends.org
There is now a per-column COMPRESSION option which can be set to pglz
(the default, and the only option in up until now) or lz4. Or, if you
like, you can set the new default_toast_compression GUC to lz4, and
then that will be the default for new table columns for which no value
is specified. We don't have lz4 support in the PostgreSQL code, so
to use lz4 compression, PostgreSQL must be built --with-lz4.
In general, TOAST compression means compression of individual column
values, not the whole tuple, and those values can either be compressed
inline within the tuple or compressed and then stored externally in
the TOAST table, so those properties also apply to this feature.
Prior to this commit, a TOAST pointer has two unused bits as part of
the va_extsize field, and a compessed datum has two unused bits as
part of the va_rawsize field. These bits are unused because the length
of a varlena is limited to 1GB; we now use them to indicate the
compression type that was used. This means we only have bit space for
2 more built-in compresison types, but we could work around that
problem, if necessary, by introducing a new vartag_external value for
any further types we end up wanting to add. Hopefully, it won't be
too important to offer a wide selection of algorithms here, since
each one we add not only takes more coding but also adds a build
dependency for every packager. Nevertheless, it seems worth doing
at least this much, because LZ4 gets better compression than PGLZ
with less CPU usage.
It's possible for LZ4-compressed datums to leak into composite type
values stored on disk, just as it is for PGLZ. It's also possible for
LZ4-compressed attributes to be copied into a different table via SQL
commands such as CREATE TABLE AS or INSERT .. SELECT. It would be
expensive to force such values to be decompressed, so PostgreSQL has
never done so. For the same reasons, we also don't force recompression
of already-compressed values even if the target table prefers a
different compression method than was used for the source data. These
architectural decisions are perhaps arguable but revisiting them is
well beyond the scope of what seemed possible to do as part of this
project. However, it's relatively cheap to recompress as part of
VACUUM FULL or CLUSTER, so this commit adjusts those commands to do
so, if the configured compression method of the table happens not to
match what was used for some column value stored therein.
Dilip Kumar. The original patches on which this work was based were
written by Ildus Kurbangaliev, and those were patches were based on
even earlier work by Nikita Glukhov, but the design has since changed
very substantially, since allow a potentially large number of
compression methods that could be added and dropped on a running
system proved too problematic given some of the architectural issues
mentioned above; the choice of which specific compression method to
add first is now different; and a lot of the code has been heavily
refactored. More recently, Justin Przyby helped quite a bit with
testing and reviewing and this version also includes some code
contributions from him. Other design input and review from Tomas
Vondra, Álvaro Herrera, Andres Freund, Oleg Bartunov, Alexander
Korotkov, and me.
Discussion: http://postgr.es/m/20170907194236.4cefce96%40wp.localdomain
Discussion: http://postgr.es/m/CAFiTN-uUpX3ck%3DK0mLEk-G_kUQY%3DSNOTeqdaNRR9FMdQrHKebw%40mail.gmail.com
Commit 86c23a6eb2 changed the option to specify that postgres will
stop all other server processes by sending the signal SIGSTOP,
from -s to -T. But previously there were comments incorrectly
explaining that SIGSTOP behavior is set by -s option. This commit
fixes them.
Author: Kyotaro Horiguchi
Reviewed-by: Fujii Masao
Discussion: https://postgr.es/m/20210316.165141.1400441966284654043.horikyota.ntt@gmail.com
We leaked the error report from PQconninfoParse, when there was
one. It seems unlikely that real usage patterns would repeat
the failure often enough to create serious bloat, but let's
back-patch anyway to keep the code similar in all branches.
Found via valgrind testing.
Back-patch to v10 where this code was added.
Discussion: https://postgr.es/m/3816764.1616104288@sss.pgh.pa.us
Because guc.c prefers to keep all its string values in malloc'd
not palloc'd storage, it has to be more careful than usual to
avoid leaks. Error exits out of string GUC hook checks failed
to clear the proposed value string, and error exits out of
ProcessGUCArray() failed to clear the malloc'd results of
ParseLongOption().
Found via valgrind testing.
This problem is ancient, so back-patch to all supported branches.
Discussion: https://postgr.es/m/3816764.1616104288@sss.pgh.pa.us
The text search cache mechanisms assume that we can clean up
an invalidated dictionary cache entry simply by resetting the
associated long-lived memory context. However, that does not work
for ispell affixes that make use of regular expressions, because
the regex library deals in plain old malloc. Hence, we leaked
compiled regex(es) any time we dropped such a cache entry. That
could quickly add up, since even a fairly trivial regex can use up
tens of kB, and a large one can eat megabytes. Add a memory context
callback to ensure that a regex gets freed when its owning cache
entry is cleared.
Found via valgrind testing.
This problem is ancient, so back-patch to all supported branches.
Discussion: https://postgr.es/m/3816764.1616104288@sss.pgh.pa.us
Some code paths in this function perform syscache lookups, which
can lead to table accesses and possibly leakage of cruft into
the caller's context. If said context is CacheMemoryContext,
we eventually will have visible bloat. But fixing this is no
harder than moving one memory context switch step. (The other
callers don't have a problem.)
Andres Freund and I independently found this via valgrind testing.
Back-patch to v12 where this code was added.
Discussion: https://postgr.es/m/20210317023101.anvejcfotwka6gaa@alap3.anarazel.de
Discussion: https://postgr.es/m/3816764.1616104288@sss.pgh.pa.us
Although these lists are usually NIL, and even when not empty
are unlikely to be large, constant relcache update traffic could
eventually result in visible bloat of CacheMemoryContext.
Found via valgrind testing.
Back-patch to v10 where this field was added.
Discussion: https://postgr.es/m/3816764.1616104288@sss.pgh.pa.us
Our coding convention requires this macro's result to be assigned
back to the original List variable. In this usage, since the
List could not become empty, there was no actual bug --- but
some compilers warned about it. Oversight in be45be9c3.
Discussion: https://postgr.es/m/35077b31-2d62-1e31-0e2e-ddb52d590b73@enterprisedb.com
With grouping sets, it's possible that some of the grouping sets are
duplicate. This is especially common with CUBE and ROLLUP clauses. For
example GROUP BY CUBE (a,b), CUBE (b,c) is equivalent to
GROUP BY GROUPING SETS (
(a, b, c),
(a, b, c),
(a, b, c),
(a, b),
(a, b),
(a, b),
(a),
(a),
(a),
(c, a),
(c, a),
(c, a),
(c),
(b, c),
(b),
()
)
Some of the grouping sets are calculated multiple times, which is mostly
unnecessary. This commit implements a new GROUP BY DISTINCT feature, as
defined in the SQL standard, which eliminates the duplicate sets.
Author: Vik Fearing
Reviewed-by: Erik Rijkers, Georgios Kokolatos, Tomas Vondra
Discussion: https://postgr.es/m/bf3805a8-d7d1-ae61-fece-761b7ff41ecc@postgresfriends.org
After a crash of a backend using temporary files, the files used to be
left behind, on the basis that it might be useful for debugging. But we
don't have any reports of anyone actually doing that, and it means the
disk usage may grow over time due to repeated backend failures (possibly
even hitting ENOSPC). So this behavior is a bit unfortunate, and fixing
it required either manual cleanup (deleting files, which is error-prone)
or restart of the instance (i.e. service disruption).
This implements automatic cleanup of temporary files, controled by a new
GUC remove_temp_files_after_crash. By default the files are removed, but
it can be disabled to restore the old behavior if needed.
Author: Euler Taveira
Reviewed-by: Tomas Vondra, Michael Paquier, Anastasia Lubennikova, Thomas Munro
Discussion: https://postgr.es/m/CAH503wDKdYzyq7U-QJqGn%3DGm6XmoK%2B6_6xTJ-Yn5WSvoHLY1Ww%40mail.gmail.com
pg_read_file() is the function that's in core, pg_file_read() is in
adminpack. But when using pg_file_read() in adminpack it calls the *C*
level function pg_read_file() in core, which probably threw the original
author off. But the error hint should be about the SQL function.
Reported-By: Sergei Kornilov
Backpatch-through: 11
Discussion: https://postgr.es/m/373021616060475@mail.yandex.ru
Commit 05c8482f7f added the implementation of parallel SELECT for
"INSERT INTO ... SELECT ..." which may incur non-negligible overhead in
the additional parallel-safety checks that it performs, even when, in the
end, those checks determine that parallelism can't be used. This is
normally only ever a problem in the case of when the target table has a
large number of partitions.
A new GUC option "enable_parallel_insert" is added, to allow insert in
parallel-mode. The default is on.
In addition to the GUC option, the user may want a mechanism to allow
inserts in parallel-mode with finer granularity at table level. The new
table option "parallel_insert_enabled" allows this. The default is true.
Author: "Hou, Zhijie"
Reviewed-by: Greg Nancarrow, Amit Langote, Takayuki Tsunakawa, Amit Kapila
Discussion: https://postgr.es/m/CAA4eK1K-cW7svLC2D7DHoGHxdAdg3P37BLgebqBOC2ZLc9a6QQ%40mail.gmail.com
Discussion: https://postgr.es/m/CAJcOf-cXnB5cnMKqWEp2E2z7Mvcd04iLVmV=qpFJrR3AcrTS3g@mail.gmail.com
When accessing replication slot stats, introduced in 9868167500,
pgstat_read_statsfiles() reads the data into newly allocated
memory. Unfortunately the current memory context at that point is the
callers, leading to leaks and use-after-free dangers.
The fix is trivial, explicitly use pgStatLocalContext. There's some
potential for further improvements, but that's outside of the scope of
this bugfix.
No backpatch necessary, feature is only in HEAD.
Author: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/20210317230447.c7uc4g3vbs4wi32i@alap3.anarazel.de
While looking at Robert Foggia's report, I noticed a passel of
other issues in the same area:
* The scheme for backslash-quoting newlines in pathnames is just
wrong; it will misbehave if the last ordinary character in a pathname
is a backslash. I'm not sure why we're bothering to allow newlines
in tablespace paths, but if we're going to do it we should do it
without introducing other problems. Hence, backslashes themselves
have to be backslashed too.
* The author hadn't read the sscanf man page very carefully, because
this code would drop any leading whitespace from the path. (I doubt
that a tablespace path with leading whitespace could happen in
practice; but if we're bothering to allow newlines in the path, it
sure seems like leading whitespace is little less implausible.) Using
sscanf for the task of finding the first space is overkill anyway.
* While I'm not 100% sure what the rationale for escaping both \r and
\n is, if the idea is to allow Windows newlines in the file then this
code failed, because it'd throw an error if it saw \r followed by \n.
* There's no cross-check for an incomplete final line in the map file,
which would be a likely apparent symptom of the improper-escaping
bug.
On the generation end, aside from the escaping issue we have:
* If needtblspcmapfile is true then do_pg_start_backup will pass back
escaped strings in tablespaceinfo->path values, which no caller wants
or is prepared to deal with. I'm not sure if there's a live bug from
that, but it looks like there might be (given the dubious assumption
that anyone actually has newlines in their tablespace paths).
* It's not being very paranoid about the possibility of random stuff
in the pg_tblspc directory. IMO we should ignore anything without an
OID-like name.
The escaping rule change doesn't seem back-patchable: it'll require
doubling of backslashes in the tablespace_map file, which is basically
a basebackup format change. The odds of that causing trouble are
considerably more than the odds of the existing bug causing trouble.
The rest of this seems somewhat unlikely to cause problems too,
so no back-patch.
Robert Foggia of Trustwave reported that read_tablespace_map()
fails to prevent an overrun of its on-stack input buffer.
Since the tablespace map file is presumed trustworthy, this does
not seem like an interesting security vulnerability, but still
we should fix it just in the name of robustness.
While here, document that pg_basebackup's --tablespace-mapping option
doesn't work with tar-format output, because it doesn't. To make it
work, we'd have to modify the tablespace_map file within the tarball
sent by the server, which might be possible but I'm not volunteering.
(Less-painful solutions would require changing the basebackup protocol
so that the source server could adjust the map. That's not very
appetizing either.)
Commit 3048898e dropped -ING from some wait event names that correspond
to barrier phases. Update the phases' names to match.
While we're here making cosmetic changes, also rename "DONE" to "FREE".
That pairs better with "ALLOCATE", and describes the activity that
actually happens in that phase (as we do for the other phases) rather
than describing a state. The distinction is clearer after bugfix commit
3b8981b6 split the phase into two. As for the growth barriers, rename
their "ALLOCATE" phase to "REALLOCATE", which is probably a better
description of what happens then. Also improve the comments about
the phases a bit.
Discussion: https://postgr.es/m/CA%2BhUKG%2BMDpwF2Eo2LAvzd%3DpOh81wUTsrwU1uAwR-v6OGBB6%2B7g%40mail.gmail.com
With very unlucky timing and parallel_leader_participation off, PHJ
could attempt to access per-batch state just as it was being freed.
There was code intended to prevent that by checking for a cleared
pointer, but it was buggy.
Fix, by introducing an extra barrier phase. The new phase
PHJ_BUILD_RUNNING means that it's safe to access the per-batch state to
find a batch to help with, and PHJ_BUILD_DONE means that it is too late.
The last to detach will free the array of per-batch state as before, but
now it will also atomically advance the phase at the same time, so that
late attachers can avoid the hazard, without the data race. This
mirrors the way per-batch hash tables are freed (see phases
PHJ_BATCH_PROBING and PHJ_BATCH_DONE).
Revealed by a one-off build farm failure, where BarrierAttach() failed a
sanity check assertion, because the memory had been clobbered by
dsa_free().
Back-patch to 11, where the code arrived.
Reported-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/20200929061142.GA29096%40paquier.xyz
Commit ce0fdbfe97 made tablesync slots permanent and allow Drop
Subscription to drop such slots. However, it is possible that before
tablesync worker could get the acknowledgment of slot creation, drop
subscription stops it and that can lead to a dangling slot on the
publisher. Prevent cancel/die interrupts while creating a slot in the
tablesync worker.
Reported-by: Thomas Munro as per buildfarm
Author: Amit Kapila
Reviewed-by: Vignesh C, Takamichi Osumi
Discussion: https://postgr.es/m/CA+hUKGJG9dWpw1cOQ2nzWU8PHjm=PTraB+KgE5648K9nTfwvxg@mail.gmail.com
Pass CURSOR_OPT_PARALLEL_OK to pg_plan_query() so that parallel plans
are considered when running the underlying SELECT query. This wasn't
done in commit e9baa5e9, which did this for CREATE MATERIALIZED VIEW,
because it wasn't yet known to be safe.
Since REFRESH always inserts into a freshly created table before later
merging or swapping the data into place with separate operations, we can
enable such plans here too.
Author: Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>
Reviewed-by: Hou, Zhijie <houzj.fnst@cn.fujitsu.com>
Reviewed-by: Luc Vlaming <luc@swarm64.com>
Reviewed-by: Thomas Munro <thomas.munro@gmail.com>
Discussion: https://postgr.es/m/CALj2ACXg-4hNKJC6nFnepRHYT4t5jJVstYvri%2BtKQHy7ydcr8A%40mail.gmail.com
After reading the root cert list from the ssl_ca_file, immediately
install it as client CA list of the new SSL context. That gives the
SSL context ownership of the list, so that SSL_CTX_free will free it.
This avoids a permanent memory leak if we fail further down in
be_tls_init(), which could happen if bogus CRL data is offered.
The leak could only amount to something if the CRL parameters get
broken after server start (else we'd just quit) and then the server
is SIGHUP'd many times without fixing the CRL data. That's rather
unlikely perhaps, but it seems worth fixing, if only because the
code is clearer this way.
While we're here, add some comments about the memory management
aspects of this logic.
Noted by Jelte Fennema and independently by Andres Freund.
Back-patch to v10; before commit de41869b6 it doesn't matter,
since we'd not re-execute this code during SIGHUP.
Discussion: https://postgr.es/m/16160-18367e56e9a28264@postgresql.org
When we have posix_fadvise() available, we can improve the performance
of an ANALYZE by quite a bit by using it to inform the kernel of the
blocks that we're going to be asking for. Similar to bitmap index
scans, the number of buffers pre-fetched is based off of the
maintenance_io_concurrency setting (for the particular tablespace or,
if not set, globally, via get_tablespace_maintenance_io_concurrency()).
Reviewed-By: Heikki Linnakangas, Tomas Vondra
Discussion: https://www.postgresql.org/message-id/VI1PR0701MB69603A433348EDCF783C6ECBF6EF0%40VI1PR0701MB6960.eurprd07.prod.outlook.com
Since commit ba79cb5dc, values of bind parameters have been logged
during errors in extended query mode. However, we only did that after
we'd collected and converted all the parameter values, thus failing to
offer any useful localization of invalid-parameter problems. Add a
separate callback that's used during parameter collection, and have it
print the parameter number, along with the input string if text input
format is used.
Justin Pryzby and Tom Lane
Discussion: https://postgr.es/m/20210104170939.GH9712@telsasoft.com
Discussion: https://postgr.es/m/CANfkH5k-6nNt-4cSv1vPB80nq2BZCzhFVR5O4VznYbsX0wZmow@mail.gmail.com
Pipeline mode in libpq lets an application avoid the Sync messages in
the FE/BE protocol that are implicit in the old libpq API after each
query. The application can then insert Sync at its leisure with a new
libpq function PQpipelineSync. This can lead to substantial reductions
in query latency.
Co-authored-by: Craig Ringer <craig.ringer@enterprisedb.com>
Co-authored-by: Matthieu Garrigues <matthieu.garrigues@gmail.com>
Co-authored-by: Álvaro Herrera <alvherre@alvh.no-ip.org>
Reviewed-by: Andres Freund <andres@anarazel.de>
Reviewed-by: Aya Iwata <iwata.aya@jp.fujitsu.com>
Reviewed-by: Daniel Vérité <daniel@manitou-mail.org>
Reviewed-by: David G. Johnston <david.g.johnston@gmail.com>
Reviewed-by: Justin Pryzby <pryzby@telsasoft.com>
Reviewed-by: Kirk Jamison <k.jamison@fujitsu.com>
Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
Reviewed-by: Nikhil Sontakke <nikhils@2ndquadrant.com>
Reviewed-by: Vaishnavi Prabakaran <VaishnaviP@fast.au.fujitsu.com>
Reviewed-by: Zhihong Yu <zyu@yugabyte.com>
Discussion: https://postgr.es/m/CAMsr+YFUjJytRyV4J-16bEoiZyH=4nj+sQ7JP9ajwz=B4dMMZw@mail.gmail.com
Discussion: https://postgr.es/m/CAJkzx4T5E-2cQe3dtv2R78dYFvz+in8PY7A8MArvLhs_pg75gg@mail.gmail.com
This commit changes WAL archiver process so that it's treated as
an auxiliary process and can use shared memory. This is an infrastructure
patch required for upcoming shared-memory based stats collector patch
series. These patch series basically need any processes including archiver
that can report the statistics to access to shared memory. Since this patch
itself is useful to simplify the code and when users monitor the status of
archiver, it's committed separately in advance.
This commit simplifies the code for WAL archiving. For example, previously
backends need to signal to archiver via postmaster when they notify
archiver that there are some WAL files to archive. On the other hand,
this commit removes that signal to postmaster and enables backends to
notify archier directly using shared latch.
Also, as the side of this change, the information about archiver process
becomes viewable at pg_stat_activity view.
Author: Kyotaro Horiguchi
Reviewed-by: Andres Freund, Álvaro Herrera, Julien Rouhaud, Tomas Vondra, Arthur Zakirov, Fujii Masao
Discussion: https://postgr.es/m/20180629.173418.190173462.horiguchi.kyotaro@lab.ntt.co.jp
Consistently set a flag variable that tracks whether the current heap
page has a dead item during lazy vacuum's heap scan. We missed the
common case where there is an preexisting (or even a new) LP_DEAD heap
line pointer.
Also make it clear that the variable might be affected by an existing
line pointer, say from an earlier opportunistic pruning operation. This
distinction is important because it's the main reason why we can't just
use the nearby tups_vacuumed variable instead.
No backpatch. In theory failing to set the page level flag variable had
no consequences. Currently it is only used to defensively check if a
page marked all visible has dead items, which should never happen anyway
(if it does then the table must be corrupt).
Author: Masahiko Sawada <sawada.mshk@gmail.com>
Diagnosed-By: Masahiko Sawada <sawada.mshk@gmail.com>
Discussion: https://postgr.es/m/CAD21AoAtZb4+HJT_8RoOXvu4HM-Zd4HKS3YSMCH6+-W=bDyh-w@mail.gmail.com
Commit 05c8482f7f added special logic related to parallel-safety of FK
triggers. This is a bit of a hack and should have instead been done by
simply setting appropriate proparallel values on those trigger functions
themselves.
Suggested-by: Tom Lane
Author: Greg Nancarrow
Reviewed-by: Amit Kapila
Discussion: https://postgr.es/m/2309260.1615485644@sss.pgh.pa.us
Simplify _bt_vacuum_needs_cleanup() functions's signature (it only needs
a single 'rel' argument now), and move it next to its sibling function
in nbtpage.c.
I believe that _bt_vacuum_needs_cleanup() was originally located in
nbtree.c due to an include dependency issue. That's no longer an issue.
Follow-up to commit 9f3665fb.
GENERATED ALWAYS AS IDENTITY implies NOT NULL, but the code failed
to complain if you overrode that with "GENERATED ALWAYS AS IDENTITY
NULL". One might think the old behavior was a feature, but it was
inconsistent because the outcome varied depending on the order of
the clauses, so it seems to have been just an oversight.
Per bug #16913 from Pavel Boev. Back-patch to v10 where identity
columns were introduced.
Vik Fearing (minor tweaks by me)
Discussion: https://postgr.es/m/16913-3b5198410f67d8c6@postgresql.org
The commit added code which used a relcache TriggerDesc field across
another cache access, which it shouldn't because the relcache doesn't
guarantee it won't get moved.
Diagnosed-by: Tom Lane
Author: Greg Nancarrow
Reviewed-by: Hou Zhijie, Amit Kapila
Discussion: https://postgr.es/m/2309260.1615485644@sss.pgh.pa.us
Since commits 9f095299 and f98b8476 we don't poll the postmaster
pipe at all during crash recovery on Linux and FreeBSD, but on other
operating systems we were still doing it for every WAL record. Do it
less frequently on operating systems where system calls are required, at
the cost of delaying exit a bit after postmaster death. This avoids
expensive system calls reported to slow down CPU-bound recovery by as
much as 10-30%.
Reviewed-by: Heikki Linnakangas <hlinnaka@iki.fi>
Reviewed-by: Fujii Masao <masao.fujii@oss.nttdata.com>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/CA%2BhUKGK1607VmtrDUHQXrsooU%3Dap4g4R2yaoByWOOA3m8xevUQ%40mail.gmail.com
Discussion: https://postgr.es/m/7261eb39-0369-f2f4-1bb5-62f3b6083b5e@iki.fi
Amit Kapila
Peter Geoghegan
Tom Lane
Stephen Frost
Fujii Masao
Michael Paquier
Tomas Vondra
Andres Freund
David Rowley
Thomas Munro
Peter Eisentraut
Heikki Linnakangas
Joe Conway
Etsuro Fujita
Noah Misch
Bruce Momjian
Andrew Dunstan
Robert Haas
Alvaro Herrera
Magnus Hagander