The code is able to compile already without warnings under
-Wshadow=compatible-local, which is itself already enabled in the tree,
and the ones fixed here showed up with the more restrictive -Wshadow.
There are more of these that we may want to look at, and the ones fixed
here made the code confusing.
Author: Peter Smith
Discussion: https://postgr.es/m/CAHut+PuR0y4ofNOxi691VTVWmBfScHV9AaBMGSpeh8+DKp81Nw@mail.gmail.com
The logical_replication_mode GUC is intended for testing and debugging
purposes, but its current name may be misleading and encourage users to make
unnecessary changes.
To avoid confusion, renaming the GUC to a less misleading name
debug_logical_replication_streaming that casual users are less likely to mistakenly
assume needs to be modified in a regular logical replication setup.
Author: Hou Zhijie <houzj.fnst@cn.fujitsu.com>
Reviewed-by: Peter Smith <smithpb2250@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/d672d774-c44b-6fec-f993-793e744f169a%40eisentraut.org
Commit 2a8b40e36 introduces the worker type field for logical replication
workers, but forgot to reset the type when the worker exits. This can lead
to recognizing a stopped worker as a valid logical replication worker.
Fix it by resetting the worker type and additionally adding the safeguard
to not use LogicalRepWorker until ->in_use is verified.
Reported-by: Thomas Munro based on cfbot reports.
Author: Hou Zhijie, Alvaro Herrera
Reviewed-by: Amit Kapila
Discussion: http://postgr.es/m/CA+hUKGK2RQh4LifVgBmkHsCYChP-65UwGXOmnCzYVa5aAt4GWg@mail.gmail.com
The SnapBuildRestoreContents() used a const value in the error message to
indicate the size in bytes it was expecting to read from the serialized
snapshot file. Fix it by reporting the size that was actually passed.
Author: Hou Zhijie
Reviewed-by: Amit Kapila
Backpatch-through: 16
Discussion: http://postgr.es/m/OS0PR01MB5716D408364F7DF32221C08D941FA@OS0PR01MB5716.jpnprd01.prod.outlook.com
We deduce a LogicalRepWorker's type from the values of several different
fields ('relid' and 'leader_pid') whenever logic needs to know it.
In fact, the logical replication worker type is already known at the time
of launching the LogicalRepWorker and it never changes for the lifetime of
that process. Instead of deducing the type, it is simpler to just store it
one time, and access it directly thereafter.
Author: Peter Smith
Reviewed-by: Amit Kapila, Bharath Rupireddy
Discussion: http://postgr.es/m/CAHut+PttPSuP0yoZ=9zLDXKqTJ=d0bhxwKaEaNcaym1XqcvDEg@mail.gmail.com
Both apply and tablesync workers were using ApplyWorkerMain() as entry
point. As the name implies, ApplyWorkerMain() should be considered as
the main function for apply workers. Tablesync worker's path was hidden
and does not have enough in common to share the same main function with
apply worker.
Also, most of the code shared by both worker types is already combined
in LogicalRepApplyLoop(). There is no need to combine the rest in
ApplyWorkerMain() anymore.
This patch introduces TablesyncWorkerMain() as a new entry point for
tablesync workers. This aims to increase code readability and would help
with future improvements like the reuse of tablesync workers in the
initial synchronization.
Author: Melih Mutlu based on suggestions by Melanie Plageman
Reviewed-by: Peter Smith, Kuroda Hayato, Amit Kapila
Discussion: http://postgr.es/m/CAGPVpCTq=rUDd4JUdaRc1XUWf4BrH2gdSNf3rtOMUGj9rPpfzQ@mail.gmail.com
Previously, when selecting an usable index for update/delete for the
REPLICA IDENTITY FULL table, in IsIndexOnlyExpression(), we used to
check if all index fields are not expressions. However, it was not
necessary, because it is enough to check if only the leftmost index
field is not an expression (and references the remote table column)
and this check has already been done by
RemoteRelContainsLeftMostColumnOnIdx().
This commit removes IsIndexOnlyExpression() and
RemoteRelContainsLeftMostColumnOnIdx() and all checks for usable
indexes for REPLICA IDENTITY FULL tables are now performed by
IsIndexUsableForReplicaIdentityFull().
Backpatch this to remain the code consistent.
Reported-by: Peter Smith
Reviewed-by: Amit Kapila, Önder Kalacı
Discussion: https://postgr.es/m/CAHut%2BPsGRE5WSsY0jcLHJEoA17MrbP9yy8FxdjC_ZOAACxbt%2BQ%40mail.gmail.com
Backpatch-through: 16
We include the message type while displaying an error context in the
apply worker. Now, while retrieving the message type string if the
message type is unknown we throw an error that will hide the original
error. So, instead, we need to simply return the string indicating an
unknown message type.
Reported-by: Ashutosh Bapat
Author: Euler Taveira, Amit Kapila
Reviewed-by: Ashutosh Bapat
Backpatch-through: 15
Discussion: https://postgr.es/m/CAExHW5suAEDW-mBZt_qu4RVxWZ1vL54-L+ci2zreYWebpzxYsA@mail.gmail.com
Commit 89e46da5e5 allowed using BTREE indexes that are neither
PRIMARY KEY nor REPLICA IDENTITY on the subscriber during apply of
update/delete. This patch extends that functionality to also allow HASH
indexes.
We explored supporting other index access methods as well but they don't
have a fixed strategy for equality operation which is required by the
current infrastructure in logical replication to scan the indexes.
Author: Kuroda Hayato
Reviewed-by: Peter Smith, Onder Kalaci, Amit Kapila
Discussion: https://postgr.es/m/TYAPR01MB58669D7414E59664E17A5827F522A@TYAPR01MB5866.jpnprd01.prod.outlook.com
Commit 89e46da5e allowed REPLICA IDENTITY FULL tables to use an index
on the subscriber during apply of update/delete. This commit clarifies
in the documentation that the leftmost field of candidate indexes must
be a column (not an expression) that references the published relation
column.
The source code comments are also updated accordingly.
Reviewed-by: Peter Smith, Amit Kapila
Discussion: https://postgr.es/m/CAD21AoDJjffEvUFKXT27Q5U8-UU9JHv4rrJ9Ke8Zkc5UPWHLvA@mail.gmail.com
Backpatch-through: 16
Clear any potential stale next_phase_at value from the snapshot
builder which otherwise may trip an assertion check ensuring
that there is no next_phase_at value.
This can be reproduced by running 80 concurrent sessions like
the below where $c is a loop counter (assumes there has been
1..$c databases created) :
echo "
CREATE TABLE replication_example(id SERIAL PRIMARY KEY,
somedata int,
text varchar(120));
SELECT 'init' FROM
pg_create_logical_replication_slot('regression_slot_$c',
'test_decoding');
SELECT data FROM
pg_logical_slot_get_changes('regression_slot_$c', NULL,
NULL, 'include-xids', '0',
'skip-empty-xacts', '1');
" | psql -d regress_$c >>psql.log &
Backpatch down to v16.
Bug: #17695
Author: Masahiko Sawada <sawada.mshk@gmail.com>
Reviewed-by: Alexander Lakhin <exclusion@gmail.com>
Reported-by: bowenshi <zxwsbg@qq.com>
Discussion: https://postgr.es/m/17695-6be9277c9295985f@postgresql.org
Backpatch-through: v16
This commit increases the size of the bgw_library_name member of
the BackgroundWorker struct from BGW_MAXLEN (96) bytes to MAXPGPATH
(default of 1024) bytes so that it can store longer file names
(e.g., absolute paths).
Author: Yurii Rashkovskii
Reviewed-by: Daniel Gustafsson, Aleksander Alekseev
Discussion: https://postgr.es/m/CA%2BRLCQyjFV5Y8tG5QgUb6gjteL4S3p%2B1gcyqWTqigyM93WZ9Pg%40mail.gmail.com
Run pgindent and pgperltidy. It seems we're still some ways
away from all committers doing this automatically. Now that
we have a buildfarm animal that will whine about poorly-indented
code, we'll try to keep the tree more tidy.
Discussion: https://postgr.es/m/3156045.1687208823@sss.pgh.pa.us
Commit 482675987 introduced "run_as_owner" subscription option so that
subscription runs with either the permissions of the subscription
owner or the permission of the table owner. However, tablesync workers
did not use this option for the initial data copy.
With this change, tablesync workers run with appropriate permissions
based on "run_as_owner" option.
Ajin Cherian, with changes and regression tests added by me.
Reported-By: Amit Kapila
Author: Ajin Cherian, Masahiko Sawada
Reviewed-by: Ajin Cherian, Amit Kapila
Discussion: https://postgr.es/m/CAA4eK1L=qzRHPEn+qeMoKQGFBzqGoLBzt_ov0A89iFFiut+ppA@mail.gmail.com
The apply worker was not reloading the configuration while processing
messages if there is a continuous flow of messages from upstream. It was
also not reloading the configuration if there is a change in the
configuration after it has waited for the message and before receiving the
new replication message. This can lead to failure in tests because we
expect that after reload, the behavior of apply worker to respect the
changed GUCs.
We found this while analyzing a rare buildfarm failure.
Author: Hou Zhijie
Reviewed-by: Amit Kapila
Discussion: https://postgr.es/m/OS0PR01MB5716AF9079CC0755CD015322947E9@OS0PR01MB5716.jpnprd01.prod.outlook.com
Run pgindent, pgperltidy, and reformat-dat-files.
This set of diffs is a bit larger than typical. We've updated to
pg_bsd_indent 2.1.2, which properly indents variable declarations that
have multi-line initialization expressions (the continuation lines are
now indented one tab stop). We've also updated to perltidy version
20230309 and changed some of its settings, which reduces its desire to
add whitespace to lines to make assignments etc. line up. Going
forward, that should make for fewer random-seeming changes to existing
code.
Discussion: https://postgr.es/m/20230428092545.qfb3y5wcu4cm75ur@alvherre.pgsql
The idea of EvalPlanQual is that we replace the query's scan of the
result relation with a single injected tuple, and see if we get a
tuple out, thereby implying that the injected tuple still passes the
query quals. (In join cases, other relations in the query are still
scanned normally.) This logic was not updated when commit 86dc90056
made it possible for a single DML query plan to have multiple result
relations, when the query target relation has inheritance or partition
children. We replaced the output for the current result relation
successfully, but other result relations were still scanned normally;
thus, if any other result relation contained a tuple satisfying the
quals, we'd think the EPQ check passed, even if it did not pass for
the injected tuple itself. This would lead to update or delete
actions getting performed when they should have been skipped due to
a conflicting concurrent update in READ COMMITTED isolation mode.
Fix by blocking all sibling result relations from emitting tuples
during an EvalPlanQual recheck. In the back branches, the fix is
complicated a bit by the need to not change the size of struct
EPQState (else we'd have ABI-breaking changes in offsets in
struct ModifyTableState). Like the back-patches of 3f7836ff6
and 4b3e37993, add a separately palloc'd struct to avoid that.
The logic is the same as in HEAD otherwise.
This is only a live bug back to v14 where 86dc90056 came in.
However, I chose to back-patch the test cases further, on the
grounds that this whole area is none too well tested. I skipped
doing so in v11 though because none of the test applied cleanly,
and it didn't quite seem worth extra work for a branch with only
six months to live.
Per report from Ante Krešić (via Aleksander Alekseev)
Discussion: https://postgr.es/m/CAJ7c6TMBTN3rcz4=AjYhLPD_w3FFT0Wq_C15jxCDn8U4tZnH1g@mail.gmail.com
The callback function pa_shutdown() accesses MyLogicalRepWorker which may
not be initialized if there is an error during the initialization of the
parallel apply worker. The other problem is that by the time it is invoked
even after the initialization of the worker, the MyLogicalRepWorker will
be reset by another callback logicalrep_worker_onexit. So, it won't have
the required information.
To fix this, register the shutdown callback after we are attached to the
worker slot.
After this fix, we observed another issue which is that sometimes the
leader apply worker tries to receive the message from the error queue that
might already be detached by the parallel apply worker leading to an
error. To prevent such an error, we ensure that the leader apply worker
detaches from the parallel apply worker's error queue before stopping it.
Reported-by: Sawada Masahiko
Author: Hou Zhijie
Reviewed-by: Sawada Masahiko, Amit Kapila
Discussion: https://postgr.es/m/CAD21AoDo+yUwNq6nTrvE2h9bB2vZfcag=jxWc7QxuWCmkDAqcA@mail.gmail.com
During exit, the logical replication apply worker tries to release session
level locks, if any. However, if the apply worker exits due to an error
before its connection is initialized, trying to release locks can lead to
assertion failure. The locks will be acquired once the worker is
initialized, so we don't need to release them till the worker
initialization is complete.
Reported-by: Alexander Lakhin
Author: Hou Zhijie based on inputs from Sawada Masahiko and Amit Kapila
Reviewed-by: Amit Kapila
Discussion: https://postgr.es/m/2185d65f-5aae-3efa-c48f-fb42b173ef5c@gmail.com
Unsurprisingly, this requires wal_level = logical to be set on the primary and
standby. The infrastructure added in 26669757b6 ensures that slots are
invalidated if the primary's wal_level is lowered.
Creating a slot on a standby waits for a xl_running_xact record to be
processed. If the primary is idle (and thus not emitting xl_running_xact
records), that can take a while. To make that faster, this commit also
introduces the pg_log_standby_snapshot() function. By executing it on the
primary, completion of slot creation on the standby can be accelerated.
Note that logical decoding on a standby does not itself enforce that required
catalog rows are not removed. The user has to use physical replication slots +
hot_standby_feedback or other measures to prevent that. If catalog rows
required for a slot are removed, the slot is invalidated.
See 6af1793954 for an overall design of logical decoding on a standby.
Bumps catversion, for the addition of the pg_log_standby_snapshot() function.
Author: "Drouvot, Bertrand" <bertranddrouvot.pg@gmail.com>
Author: Andres Freund <andres@anarazel.de> (in an older version)
Author: Amit Khandekar <amitdkhan.pg@gmail.com> (in an older version)
Reviewed-by: Andres Freund <andres@anarazel.de>
Reviewed-by: FabrÌzio de Royes Mello <fabriziomello@gmail.com>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Reviewed-By: Robert Haas <robertmhaas@gmail.com>
Previously we had checks for this in multiple places. Support for logical
decoding on standbys will add other forms of invalidation, making it worth
while to centralize the checks.
This slightly changes the error message for both the walsender and SQL
interface. Particularly the SQL interface error was inaccurate, as the "This
slot has never previously reserved WAL" portion was unreachable.
Reviewed-by: "Drouvot, Bertrand" <bertranddrouvot.pg@gmail.com>
Reviewed-by: Melanie Plageman <melanieplageman@gmail.com>
Discussion: https://postgr.es/m/20230407075009.igg7be27ha2htkbt@awork3.anarazel.de
This option is normally false, but can be set to true to obtain
the legacy behavior where the subscription runs with the permissions
of the subscription owner rather than the permissions of the
table owner. The advantages of this mode are (1) it doesn't require
that the subscription owner have permission to SET ROLE to each
table owner and (2) since no role switching occurs, the
SECURITY_RESTRICTED_OPERATION restrictions do not apply.
On the downside, it allows any table owner to easily usurp
the privileges of the subscription owner - basically, to take
over their account. Because that's generally quite undesirable,
we don't make this mode the default, but we do make it available,
just in case the new behavior causes too many problems for someone.
Discussion: http://postgr.es/m/CA+TgmoZ-WEeG6Z14AfH7KhmpX2eFh+tZ0z+vf0=eMDdbda269g@mail.gmail.com
Up until now, logical replication actions have been performed as the
subscription owner, who will generally be a superuser. Commit
cec57b1a0f documented hazards
associated with that situation, namely, that any user who owns a
table on the subscriber side could assume the privileges of the
subscription owner by attaching a trigger, expression index, or
some other kind of executable code to it. As a remedy, it suggested
not creating configurations where users who are not fully trusted
own tables on the subscriber.
Although that will work, it basically precludes using logical
replication in the way that people typically want to use it,
namely, to replicate a database from one node to another
without necessarily having any restrictions on which database
users can own tables. So, instead, change logical replication to
execute INSERT, UPDATE, DELETE, and TRUNCATE operations as the
table owner when they are replicated.
Since this involves switching the active user frequently within
a session that is authenticated as the subscription user, also
impose SECURITY_RESTRICTED_OPERATION restrictions on logical
replication code. As an exception, if the table owner can SET
ROLE to the subscription owner, these restrictions have no
security value, so don't impose them in that case.
Subscription owners are now required to have the ability to
SET ROLE to every role that owns a table that the subscription
is replicating. If they don't, replication will fail. Superusers,
who normally own subscriptions, satisfy this property by default.
Non-superusers users who own subscriptions will need to be
granted the roles that own relevant tables.
Patch by me, reviewed (but not necessarily in its entirety) by
Jelte Fennema, Jeff Davis, and Noah Misch.
Discussion: http://postgr.es/m/CA+TgmoaSCkg9ww9oppPqqs+9RVqCexYCE6Aq=UsYPfnOoDeFkw@mail.gmail.com
This role can be granted to non-superusers to allow them to issue
CREATE SUBSCRIPTION. The non-superuser must additionally have CREATE
permissions on the database in which the subscription is to be
created.
Most forms of ALTER SUBSCRIPTION, including ALTER SUBSCRIPTION .. SKIP,
now require only that the role performing the operation own the
subscription, or inherit the privileges of the owner. However, to
use ALTER SUBSCRIPTION ... RENAME or ALTER SUBSCRIPTION ... OWNER TO,
you also need CREATE permission on the database. This is similar to
what we do for schemas. To change the owner of a schema, you must also
have permission to SET ROLE to the new owner, similar to what we do
for other object types.
Non-superusers are required to specify a password for authentication
and the remote side must use the password, similar to what is required
for postgres_fdw and dblink. A superuser who wants a non-superuser to
own a subscription that does not rely on password authentication may
set the new password_required=false property on that subscription. A
non-superuser may not set password_required=false and may not modify a
subscription that already has password_required=false.
This new password_required subscription property works much like the
eponymous postgres_fdw property. In both cases, the actual semantics
are that a password is not required if either (1) the property is set
to false or (2) the relevant user is the superuser.
Patch by me, reviewed by Andres Freund, Jeff Davis, Mark Dilger,
and Stephen Frost (but some of those people did not fully endorse
all of the decisions that the patch makes).
Discussion: http://postgr.es/m/CA+TgmoaDH=0Xj7OBiQnsHTKcF2c4L+=gzPBUKSJLh8zed2_+Dg@mail.gmail.com
This patch allows copying tables in the binary format during table
synchronization when the binary option for a subscription is enabled.
Previously, tables are copied in text format even if the subscription is
created with the binary option enabled. Copying tables in binary format
may reduce the time spent depending on column types.
A binary copy for initial table synchronization is supported only when
both publisher and subscriber are v16 or later.
Author: Melih Mutlu
Reviewed-by: Peter Smith, Shi yu, Euler Taveira, Vignesh C, Kuroda Hayato, Osumi Takamichi, Bharath Rupireddy, Hou Zhijie
Discussion: https://postgr.es/m/CAGPVpCQvAziCLknEnygY0v1-KBtg%2BOm-9JHJYZOnNPKFJPompw%40mail.gmail.com
Currently, there are quite a few places in reorderbuffer.c that tries to
access top-transaction for a subtransaction. This makes the code to access
top-transaction consistent and easier to follow.
Author: Peter Smith
Reviewed-by: Vignesh C, Sawada Masahiko
Discussion: https://postgr.es/m/CAHut+PuCznOyTqBQwjRUu-ibG-=KHyCv-0FTcWQtZUdR88umfg@mail.gmail.com
Using REPLICA IDENTITY FULL on the publisher can lead to a full table scan
per tuple change on the subscription when REPLICA IDENTITY or PK index is
not available. This makes REPLICA IDENTITY FULL impractical to use apart
from some small number of use cases.
This patch allows using indexes other than PRIMARY KEY or REPLICA
IDENTITY on the subscriber during apply of update/delete. The index that
can be used must be a btree index, not a partial index, and it must have
at least one column reference (i.e. cannot consist of only expressions).
We can uplift these restrictions in the future. There is no smart
mechanism to pick the index. If there is more than one index that
satisfies these requirements, we just pick the first one. We discussed
using some of the optimizer's low-level APIs for this but ruled it out
as that can be a maintenance burden in the long run.
This patch improves the performance in the vast majority of cases and the
improvement is proportional to the amount of data in the table. However,
there could be some regression in a small number of cases where the indexes
have a lot of duplicate and dead rows. It was discussed that those are
mostly impractical cases but we can provide a table or subscription level
option to disable this feature if required.
Author: Onder Kalaci, Amit Kapila
Reviewed-by: Peter Smith, Shi yu, Hou Zhijie, Vignesh C, Kuroda Hayato, Amit Kapila
Discussion: https://postgr.es/m/CACawEhVLqmAAyPXdHEPv1ssU2c=dqOniiGz7G73HfyS7+nGV4w@mail.gmail.com
While testing a fix for bug #17823, I discovered that EvalPlanQualStart
failed to copy es_rteperminfos from the parent EState, resulting in
failure if anything in EPQ execution wanted to consult that information.
This led me to conclude that commit a61b1f748 had been too haphazard
about where to fill es_rteperminfos, and that we need to be sure that
that happens exactly where es_range_table gets filled. So I changed the
signature of ExecInitRangeTable to help ensure that this new requirement
doesn't get missed. (Indeed, pgoutput.c was also failing to fill it.
Maybe we don't ever need it there, but I wouldn't bet on that.)
No test case yet; one will arrive with the fix for #17823.
But that needs to be back-patched, while this fix is HEAD-only.
Discussion: https://postgr.es/m/17823-b64909cf7d63de84@postgresql.org
This function has been semi-deprecated ever since we invented
bms_next_member(). Its habit of scribbling on the input bitmapset
isn't great, plus for sufficiently large bitmapsets it would take
O(N^2) time to complete a loop. Now we have the additional problem
that reducing the input to empty while leaving it still accessible
would violate a planned invariant. So let's just get rid of it,
after updating the few extant callers to use bms_next_member().
Patch by me; thanks to Nathan Bossart and Richard Guo for review.
Discussion: https://postgr.es/m/1159933.1677621588@sss.pgh.pa.us
Whe decoding a transactional logical message, logicalmsg_decode called
SnapBuildGetOrBuildSnapshot. But we may not have a consistent snapshot
yet at that point. We don't actually need the snapshot in this case
(during replay we'll have the snapshot from the transaction), so in
practice this is harmless. But in assert-enabled build this crashes.
Fixed by requesting the snapshot only in non-transactional case, where
we are guaranteed to have SNAPBUILD_CONSISTENT.
Backpatch to 11. The issue exists since 9.6.
Backpatch-through: 11
Reviewed-by: Andres Freund
Discussion: https://postgr.es/m/84d60912-6eab-9b84-5de3-41765a5449e8@enterprisedb.com
d9d7fe68d3 made use of an existing wait event when sending data from the
apply worker, but we should have invented a new wait event since this is a
new place to wait.
This patch corrects the mistake by using a new wait event
"LogicalApplySendData".
Author: Hou Zhijie
Reviewed-by: Peter Smith
Discussion: https://postgr.es/m/CA+TgmobWzbr9H3yN3dLVckviEZKemPwd+XyCFKEgyZQZhgP66Q@mail.gmail.com
