Commit Graph

391 Commits

Author SHA1 Message Date
Stephen Frost 3d4fa227bc Add support for Kerberos credential delegation
Support GSSAPI/Kerberos credentials being delegated to the server by a
client.  With this, a user authenticating to PostgreSQL using Kerberos
(GSSAPI) credentials can choose to delegate their credentials to the
PostgreSQL server (which can choose to accept them, or not), allowing
the server to then use those delegated credentials to connect to
another service, such as with postgres_fdw or dblink or theoretically
any other service which is able to be authenticated using Kerberos.

Both postgres_fdw and dblink are changed to allow non-superuser
password-less connections but only when GSSAPI credentials have been
delegated to the server by the client and GSSAPI is used to
authenticate to the remote system.

Authors: Stephen Frost, Peifeng Qiu
Reviewed-By: David Christensen
Discussion: https://postgr.es/m/CO1PR05MB8023CC2CB575E0FAAD7DF4F8A8E29@CO1PR05MB8023.namprd05.prod.outlook.com
2023-04-07 21:58:04 -04:00
Andres Freund ac8d53dae5 Track IO times in pg_stat_io
a9c70b46db and 8aaa04b32S added counting of IO operations to a new view,
pg_stat_io. Now, add IO timing for reads, writes, extends, and fsyncs to
pg_stat_io as well.

This combines the tracking for pgBufferUsage with the tracking for pg_stat_io
into a new function pgstat_count_io_op_time(). This should make it a bit
easier to avoid the somewhat costly instr_time conversion done for
pgBufferUsage.

Author: Melanie Plageman <melanieplageman@gmail.com>
Reviewed-by: Andres Freund <andres@anarazel.de>
Reviewed-by: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Discussion: https://postgr.es/m/flat/CAAKRu_ay5iKmnbXZ3DsauViF3eMxu4m1oNnJXqV_HyqYeg55Ww%40mail.gmail.com
2023-04-07 17:04:56 -07:00
Andres Freund 8aaa04b32d Track shared buffer hits in pg_stat_io
Among other things, this should make it easier to calculate a useful cache hit
ratio by excluding buffer reads via buffer access strategies. As buffer access
strategies reuse buffers (and thus evict the prior buffer contents), it is
normal to see reads on repeated scans of the same data.

Author: Melanie Plageman <melanieplageman@gmail.com>
Reviewed-by: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/CAAKRu_beMa9Hzih40%3DXPYqhDVz6tsgUGTrhZXRo%3Dunp%2Bszb%3DUA%40mail.gmail.com
2023-03-30 19:24:21 -07:00
Amit Kapila 062a844424 Avoid syncing data twice for the 'publish_via_partition_root' option.
When there are multiple publications for a subscription and one of those
publishes via the parent table by using publish_via_partition_root and the
other one directly publishes the child table, we end up copying the same
data twice during initial synchronization. The reason for this was that we
get both the parent and child tables from the publisher and try to copy
the data for both of them.

This patch extends the function pg_get_publication_tables() to take a
publication list as its input parameter. This allows us to exclude a
partition table whose ancestor is published by the same publication list.

This problem does exist in back-branches but we decide to fix it there in
a separate commit if required. The fix for back-branches requires quite
complicated changes to fetch the required table information from the
publisher as we can't update the function pg_get_publication_tables() in
back-branches. We are not sure whether we want to deviate and complicate
the code in back-branches for this problem as there are no field reports
yet.

Author: Wang wei
Reviewed-by: Peter Smith, Jacob Champion, Kuroda Hayato, Vignesh C, Osumi Takamichi, Amit Kapila
Discussion: https://postgr.es/m/OS0PR01MB57167F45D481F78CDC5986F794B99@OS0PR01MB5716.jpnprd01.prod.outlook.com
2023-03-29 10:46:58 +05:30
Peter Geoghegan ae4fdde135 Count updates that move row to a new page.
Add pgstat counter to track row updates that result in the successor
version going to a new heap page, leaving behind an original version
whose t_ctid points to the new version.  The current count is shown by
the n_tup_newpage_upd column of each of the pg_stat_*_tables views.

The new n_tup_newpage_upd column complements the existing n_tup_hot_upd
and n_tup_upd columns.  Tables that have high n_tup_newpage_upd values
(relative to n_tup_upd) are good candidates for tuning heap fillfactor.

Corey Huinker, with small tweaks by me.

Author: Corey Huinker <corey.huinker@gmail.com>
Reviewed-By: Peter Geoghegan <pg@bowt.ie>
Reviewed-By: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/CADkLM=ded21M9iZ36hHm-vj2rE2d=zcKpUQMds__Xm2pxLfHKA@mail.gmail.com
2023-03-23 11:16:17 -07:00
Dean Rasheed a7d71c41db Fix mishandling of OLD/NEW references in subqueries in rule actions.
If a rule action contains a subquery that refers to columns from OLD
or NEW, then those are really lateral references, and the planner will
complain if it sees such things in a subquery that isn't marked as
lateral. However, at rule-definition time, the user isn't required to
mark the subquery with LATERAL, and so it can fail when the rule is
used.

Fix this by marking such subqueries as lateral in the rewriter, at the
point where they're used.

Dean Rasheed and Tom Lane, per report from Alexander Lakhin.
Back-patch to all supported branches.

Discussion: https://postgr.es/m/5e09da43-aaba-7ea7-0a51-a2eb981b058b%40gmail.com
2023-02-25 14:41:12 +00:00
Tom Lane 393430f575 Print the correct aliases for DML target tables in ruleutils.
ruleutils.c blindly printed the user-given alias (or nothing if there
hadn't been one) for the target table of INSERT/UPDATE/DELETE queries.
That works a large percentage of the time, but not always: for queries
appearing in WITH, it's possible that we chose a different alias to
avoid conflict with outer-scope names.  Since the chosen alias would
be used in any Var references to the target table, this'd lead to an
inconsistent printout with consequences such as dump/restore failures.

The correct logic for printing (or not) a relation alias was embedded
in get_from_clause_item.  Factor it out to a separate function so that
we don't need a jointree node to use it.  (Only a limited part of that
function can be reached from these new call sites, but this seems like
the cleanest non-duplicative factorization.)

In passing, I got rid of a redundant "\d+ rules_src" step in rules.sql.

Initial report from Jonathan Katz; thanks to Vignesh C for analysis.
This has been broken for a long time, so back-patch to all supported
branches.

Discussion: https://postgr.es/m/e947fa21-24b2-f922-375a-d4f763ef3e4b@postgresql.org
Discussion: https://postgr.es/m/CALDaNm1MMntjmT_NJGp-Z=xbF02qHGAyuSHfYHias3TqQbPF2w@mail.gmail.com
2023-02-17 16:40:34 -05:00
Andres Freund a9c70b46db Add pg_stat_io view, providing more detailed IO statistics
Builds on 28e626bde0 and f30d62c2fc. See the former for motivation.

Rows of the view show IO operations for a particular backend type, IO target
object, IO context combination (e.g. a client backend's operations on
permanent relations in shared buffers) and each column in the view is the
total number of IO Operations done (e.g. writes). So a cell in the view would
be, for example, the number of blocks of relation data written from shared
buffers by client backends since the last stats reset.

In anticipation of tracking WAL IO and non-block-oriented IO (such as
temporary file IO), the "op_bytes" column specifies the unit of the "reads",
"writes", and "extends" columns for a given row.

Rows for combinations of IO operation, backend type, target object and context
that never occur, are ommitted entirely. For example, checkpointer will never
operate on temporary relations.

Similarly, if an IO operation never occurs for such a combination, the IO
operation's cell will be null, to distinguish from 0 observed IO
operations. For example, bgwriter should not perform reads.

Note that some of the cells in the view are redundant with fields in
pg_stat_bgwriter (e.g. buffers_backend). For now, these have been kept for
backwards compatibility.

Bumps catversion.

Author: Melanie Plageman <melanieplageman@gmail.com>
Author: Samay Sharma <smilingsamay@gmail.com>
Reviewed-by: Maciek Sakrejda <m.sakrejda@gmail.com>
Reviewed-by: Lukas Fittl <lukas@fittl.com>
Reviewed-by: Andres Freund <andres@anarazel.de>
Reviewed-by: Justin Pryzby <pryzby@telsasoft.com>
Discussion: https://postgr.es/m/20200124195226.lth52iydq2n2uilq@alap3.anarazel.de
2023-02-11 09:52:15 -08:00
Tom Lane 47bb9db759 Get rid of the "new" and "old" entries in a view's rangetable.
The rule system needs "old" and/or "new" pseudo-RTEs in rule actions
that are ON INSERT/UPDATE/DELETE.  Historically it's put such entries
into the ON SELECT rules of views as well, but those are really quite
vestigial.  The only thing we've used them for is to carry the
view's relid forward to AcquireExecutorLocks (so that we can
re-lock the view to verify it hasn't changed before re-using a plan)
and to carry its relid and permissions data forward to execution-time
permissions checks.  What we can do instead of that is to retain
these fields of the RTE_RELATION RTE for the view even after we
convert it to an RTE_SUBQUERY RTE.  This requires a tiny amount of
extra complication in the planner and AcquireExecutorLocks, but on
the other hand we can get rid of the logic that moves that data from
one place to another.

The principal immediate benefit of doing this, aside from a small
saving in the pg_rewrite data for views, is that these pseudo-RTEs
no longer trigger ruleutils.c's heuristic about qualifying variable
names when the rangetable's length is more than 1.  That results
in quite a number of small simplifications in regression test outputs,
which are all to the good IMO.

Bump catversion because we need to dump a few more fields of
RTE_SUBQUERY RTEs.  While those will always be zeroes anyway in
stored rules (because we'd never populate them until query rewrite)
they are useful for debugging, and it seems like we'd better make
sure to transmit such RTEs accurately in plans sent to parallel
workers.  I don't think the executor actually examines these fields
after startup, but someday it might.

This is a second attempt at committing 1b4d280ea.  The difference
from the first time is that now we can add some filtering rules to
AdjustUpgrade.pm to allow cross-version upgrade testing to pass
despite all the cosmetic changes in CREATE VIEW outputs.

Amit Langote (filtering rules by me)

Discussion: https://postgr.es/m/CA+HiwqEf7gPN4Hn+LoZ4tP2q_Qt7n3vw7-6fJKOf92tSEnX6Gg@mail.gmail.com
Discussion: https://postgr.es/m/891521.1673657296@sss.pgh.pa.us
2023-01-18 13:23:57 -05:00
Amit Kapila d540a02a72 Display the leader apply worker's PID for parallel apply workers.
Add leader_pid to pg_stat_subscription. leader_pid is the process ID of
the leader apply worker if this process is a parallel apply worker. If
this field is NULL, it indicates that the process is a leader apply
worker or a synchronization worker. The new column makes it easier to
distinguish parallel apply workers from other kinds of workers and helps
to identify the leader for the parallel workers corresponding to a
particular subscription.

Additionally, update the leader_pid column in pg_stat_activity as well to
display the PID of the leader apply worker for parallel apply workers.

Author: Hou Zhijie
Reviewed-by: Peter Smith, Sawada Masahiko, Amit Kapila, Shveta Mallik
Discussion: https://postgr.es/m/CAA4eK1+wyN6zpaHUkCLorEWNx75MG0xhMwcFhvjqm2KURZEAGw@mail.gmail.com
2023-01-18 09:03:12 +05:30
Amit Kapila b7ae039536 Ignore dropped and generated columns from the column list.
We don't allow different column lists for the same table in the different
publications of the single subscription. A publication with a column list
except for dropped and generated columns should be considered the same as
a publication with no column list (which implicitly includes all columns
as part of the columns list). However, as we were not excluding the
dropped and generated columns from the column list combining such
publications leads to an error "cannot use different column lists for
table ...".

We decided not to backpatch this fix as there is a risk of users seeing
this as a behavior change and also we didn't see any field report of this
case.

Author: Shi yu
Reviewed-by: Amit Kapila
Discussion: https://postgr.es/m/OSZPR01MB631091CCBC56F195B1B9ACB0FDFE9@OSZPR01MB6310.jpnprd01.prod.outlook.com
2023-01-13 14:49:23 +05:30
Tom Lane f0e6d6d3c9 Revert "Get rid of the "new" and "old" entries in a view's rangetable."
This reverts commit 1b4d280ea1.
It's broken the buildfarm members that run cross-version-upgrade tests,
because they're not prepared to deal with cosmetic differences between
CREATE VIEW commands emitted by older servers and HEAD.  Even if we had
a solution to that, which we don't, it'd take some time to roll it out
to the affected animals.  This improvement isn't valuable enough to
justify addressing that problem on an emergency basis, so revert it
for now.
2023-01-11 23:01:22 -05:00
Tom Lane 1b4d280ea1 Get rid of the "new" and "old" entries in a view's rangetable.
The rule system needs "old" and/or "new" pseudo-RTEs in rule actions
that are ON INSERT/UPDATE/DELETE.  Historically it's put such entries
into the ON SELECT rules of views as well, but those are really quite
vestigial.  The only thing we've used them for is to carry the
view's relid forward to AcquireExecutorLocks (so that we can
re-lock the view to verify it hasn't changed before re-using a plan)
and to carry its relid and permissions data forward to execution-time
permissions checks.  What we can do instead of that is to retain
these fields of the RTE_RELATION RTE for the view even after we
convert it to an RTE_SUBQUERY RTE.  This requires a tiny amount of
extra complication in the planner and AcquireExecutorLocks, but on
the other hand we can get rid of the logic that moves that data from
one place to another.

The principal immediate benefit of doing this, aside from a small
saving in the pg_rewrite data for views, is that these pseudo-RTEs
no longer trigger ruleutils.c's heuristic about qualifying variable
names when the rangetable's length is more than 1.  That results
in quite a number of small simplifications in regression test outputs,
which are all to the good IMO.

Bump catversion because we need to dump a few more fields of
RTE_SUBQUERY RTEs.  While those will always be zeroes anyway in
stored rules (because we'd never populate them until query rewrite)
they are useful for debugging, and it seems like we'd better make
sure to transmit such RTEs accurately in plans sent to parallel
workers.  I don't think the executor actually examines these fields
after startup, but someday it might.

Amit Langote

Discussion: https://postgr.es/m/CA+HiwqEf7gPN4Hn+LoZ4tP2q_Qt7n3vw7-6fJKOf92tSEnX6Gg@mail.gmail.com
2023-01-11 19:41:09 -05:00
Alvaro Herrera a61b1f7482
Rework query relation permission checking
Currently, information about the permissions to be checked on relations
mentioned in a query is stored in their range table entries.  So the
executor must scan the entire range table looking for relations that
need to have permissions checked.  This can make the permission checking
part of the executor initialization needlessly expensive when many
inheritance children are present in the range range.  While the
permissions need not be checked on the individual child relations, the
executor still must visit every range table entry to filter them out.

This commit moves the permission checking information out of the range
table entries into a new plan node called RTEPermissionInfo.  Every
top-level (inheritance "root") RTE_RELATION entry in the range table
gets one and a list of those is maintained alongside the range table.
This new list is initialized by the parser when initializing the range
table.  The rewriter can add more entries to it as rules/views are
expanded.  Finally, the planner combines the lists of the individual
subqueries into one flat list that is passed to the executor for
checking.

To make it quick to find the RTEPermissionInfo entry belonging to a
given relation, RangeTblEntry gets a new Index field 'perminfoindex'
that stores the corresponding RTEPermissionInfo's index in the query's
list of the latter.

ExecutorCheckPerms_hook has gained another List * argument; the
signature is now:
typedef bool (*ExecutorCheckPerms_hook_type) (List *rangeTable,
					      List *rtePermInfos,
					      bool ereport_on_violation);
The first argument is no longer used by any in-core uses of the hook,
but we leave it in place because there may be other implementations that
do.  Implementations should likely scan the rtePermInfos list to
determine which operations to allow or deny.

Author: Amit Langote <amitlangote09@gmail.com>
Discussion: https://postgr.es/m/CA+HiwqGjJDmUhDSfv-U2qhKJjt9ST7Xh9JXC_irsAQ1TAUsJYg@mail.gmail.com
2022-12-06 16:09:24 +01:00
Dean Rasheed 2605643a3a Fix DEFAULT handling for multi-row INSERT rules.
When updating a relation with a rule whose action performed an INSERT
from a multi-row VALUES list, the rewriter might skip processing the
VALUES list, and therefore fail to replace any DEFAULTs in it. This
would lead to an "unrecognized node type" error.

The reason was that RewriteQuery() assumed that a query doing an
INSERT from a multi-row VALUES list would necessarily only have one
item in its fromlist, pointing to the VALUES RTE to read from. That
assumption is correct for the original query, but not for product
queries produced for rule actions. In such cases, there may be
multiple items in the fromlist, possibly including multiple VALUES
RTEs.

What is required instead is for RewriteQuery() to skip any RTEs from
the product query's originating query, which might include one or more
already-processed VALUES RTEs. What's left should then include at most
one VALUES RTE (from the rule action) to be processed.

Patch by me. Thanks to Tom Lane for reviewing.

Back-patch to all supported branches.

Discussion: https://postgr.es/m/CAEZATCV39OOW7LAR_Xq4i%2BLc1Byux%3DeK3Q%3DHD_pF1o9LBt%3DphA%40mail.gmail.com
2022-12-03 12:11:33 +00:00
Tom Lane b23cd185fd Remove logic for converting a table to a view.
Up to now we have allowed manual creation of an ON SELECT rule on
a table to convert it into a view.  That was never anything but a
horrid, error-prone hack though.  pg_dump used to rely on that
behavior to deal with cases involving circular dependencies,
where a dependency loop could be broken by separating the creation
of a view from installation of its ON SELECT rule.  However, we
changed pg_dump to use CREATE OR REPLACE VIEW for that in commit
d8c05aff5 (which was later back-patched as far as 9.4), so there's
not a good argument anymore for continuing to support the behavior.

The proximate reason for axing it now is that we found that the
new statistics code has failure modes associated with the relkind
change caused by this behavior.  We'll patch around that in v15,
but going forward it seems like a better idea to get rid of the
need to support relkind changes.

Discussion: https://postgr.es/m/CALDaNm2yXz+zOtv7y5zBd5WKT8O0Ld3YxikuU3dcyCvxF7gypA@mail.gmail.com
2022-12-02 12:14:32 -05:00
Michael Paquier a54b658ce7 Add support for file inclusions in HBA and ident configuration files
pg_hba.conf and pg_ident.conf gain support for three record keywords:
- "include", to include a file.
- "include_if_exists", to include a file, ignoring it if missing.
- "include_dir", to include a directory of files.  These are classified
by name (C locale, mostly) and need to be prefixed by ".conf", hence
following the same rules as GUCs.

This commit relies on the refactoring pieces done in efc9816, ad6c528,
783e8c6 and 1b73d0b, adding a small wrapper to build a list of
TokenizedAuthLines (tokenize_include_file), and the code is shaped to
offer some symmetry with what is done for GUCs with the same options.

pg_hba_file_rules and pg_ident_file_mappings gain a new field called
file_name, to track from which file a record is located, taking
advantage of the addition of rule_number in c591300 to offer an
organized view of the HBA or ident records loaded.

Bump catalog version.

Author: Julien Rouhaud
Reviewed-by: Michael Paquier
Discussion: https://postgr.es/m/20220223045959.35ipdsvbxcstrhya@jrouhaud
2022-11-24 13:51:34 +09:00
Tom Lane 56d0ed3b75 Give better hints for ambiguous or unreferenceable columns.
Examine ParseNamespaceItem flags to detect whether a column name
is unreferenceable for lack of LATERAL, or could be referenced if
a qualified name were used, and give better hints for such cases.
Also, don't phrase the message to imply that there's only one
matching column when there is really more than one.

Many of the regression test output changes are not very interesting,
but just reflect reclassifying the "There is a column ... but it
cannot be referenced from this part of the query" messages as DETAIL
rather than HINT.  They are details per our style guide, in the sense
of being factual rather than offering advice; and this change provides
room to offer actual HINTs about what to do.

While here, adjust the fuzzy-name-matching code to be a shade less
impenetrable.  It was overloading the meanings of FuzzyAttrMatchState
fields way too much IMO, so splitting them into multiple fields seems
to make it clearer.  It's not like we need to shave bytes in that
struct.

Per discussion of bug #17233 from Alexander Korolev.

Discussion: https://postgr.es/m/17233-afb9d806aaa64b17@postgresql.org
2022-11-22 18:46:31 -05:00
Michael Paquier c591300a8f Add rule_number to pg_hba_file_rules and map_number to pg_ident_file_mappings
These numbers are strictly-monotone identifiers assigned to each rule
of pg_hba_file_rules and each map of pg_ident_file_mappings when loading
the HBA and ident configuration files, indicating the order in which
they are checked at authentication time, until a match is found.

With only one file loaded currently, this is equivalent to the line
numbers assigned to the entries loaded if one wants to know their order,
but this becomes mandatory once the inclusion of external files is
added to the HBA and ident files to be able to know in which order the
rules and/or maps are applied at authentication.  Note that NULL is used
when a HBA or ident entry cannot be parsed or validated, aka when an
error exists, contrary to the line number.

Bump catalog version.

Author: Julien Rouhaud
Discussion: https://postgr.es/m/20220223045959.35ipdsvbxcstrhya@jrouhaud
2022-10-26 15:22:15 +09:00
Andres Freund c037471832 pgstat: Track time of the last scan of a relation
It can be useful to know when a relation has last been used, e.g., when
evaluating whether an index is still required. It was already possible to
infer the time of the last usage by tracking, e.g.,
pg_stat_all_indexes.idx_scan over time. But far from everybody does so.

To make it easier to detect the last time a relation has been scanned, track
that time in each relation's pgstat entry. To minimize overhead a) the
timestamp is updated only when the backend pending stats entry is flushed to
shared stats b) the last transaction's stop timestamp is used as the
timestamp.

Bumps catalog and stats format versions.

Author: Dave Page <dpage@pgadmin.org>
Reviewed-by: Andres Freund <andres@anarazel.de>
Reviewed-by: Bruce Momjian <bruce@momjian.us>
Reviewed-by: Vik Fearing <vik@postgresfriends.org>
Discussion: https://postgr.es/m/CA+OCxozrVHNFVEPkweUHMZje+t1tfY816d9MZYc6eZwOOusOaQ@mail.gmail.com
2022-10-14 11:11:34 -07:00
Tom Lane 20b6847176 Fix new pg_publication_tables query.
The addition of published column names forgot to filter on attisdropped,
leading to cases where you could see "........pg.dropped.1........"
or the like as a reportedly-published column.

While we're here, rewrite the new subquery to get a more efficient plan
for it.

Hou Zhijie, per report from Jaime Casanova.  Back-patch to v15 where
the bug was introduced.  (Sadly, this means we need a post-beta4
catversion bump before beta4 has even hit the streets.  I see no
good alternative though.)

Discussion: https://postgr.es/m/Yxa1SU4nH2HfN3/i@ahch-to
2022-09-06 18:00:32 -04:00
Peter Eisentraut 84ad713cf8 Add result_types column to pg_prepared_statements view
Containing the types of the columns returned by the prepared
statement.

Prompted by question from IRC user mlvzk.

Author: Dagfinn Ilmari Mannsåker <ilmari@ilmari.org>
Discussion: https://www.postgresql.org/message-id/flat/871qwpo7te.fsf@wibble.ilmari.org
2022-07-05 07:23:32 +02:00
Amit Kapila 0ff20288e1 Extend pg_publication_tables to display column list and row filter.
Commit 923def9a53 and 52e4f0cd47 allowed to specify column lists and row
filters for publication tables. This commit extends the
pg_publication_tables view and pg_get_publication_tables function to
display that information.

This information will be useful to users and we also need this for the
later commit that prohibits combining multiple publications with different
column lists for the same table.

Author: Hou Zhijie
Reviewed By: Amit Kapila, Alvaro Herrera, Shi Yu, Takamichi Osumi
Discussion: https://postgr.es/m/202204251548.mudq7jbqnh7r@alvherre.pgsql
2022-05-19 08:20:55 +05:30
Peter Eisentraut 80c877271a Fix whitespace 2022-04-09 16:17:41 +02:00
Tomas Vondra 2c7ea57e56 Revert "Logical decoding of sequences"
This reverts a sequence of commits, implementing features related to
logical decoding and replication of sequences:

 - 0da92dc530
 - 80901b3291
 - b779d7d8fd
 - d5ed9da41d
 - a180c2b34d
 - 75b1521dae
 - 2d2232933b
 - 002c9dd97a
 - 05843b1aa4

The implementation has issues, mostly due to combining transactional and
non-transactional behavior of sequences. It's not clear how this could
be fixed, but it'll require reworking significant part of the patch.

Discussion: https://postgr.es/m/95345a19-d508-63d1-860a-f5c2f41e8d40@enterprisedb.com
2022-04-07 20:06:36 +02:00
Thomas Munro 5dc0418fab Prefetch data referenced by the WAL, take II.
Introduce a new GUC recovery_prefetch.  When enabled, look ahead in the
WAL and try to initiate asynchronous reading of referenced data blocks
that are not yet cached in our buffer pool.  For now, this is done with
posix_fadvise(), which has several caveats.  Since not all OSes have
that system call, "try" is provided so that it can be enabled where
available.  Better mechanisms for asynchronous I/O are possible in later
work.

Set to "try" for now for test coverage.  Default setting to be finalized
before release.

The GUC wal_decode_buffer_size limits the distance we can look ahead in
bytes of decoded data.

The existing GUC maintenance_io_concurrency is used to limit the number
of concurrent I/Os allowed, based on pessimistic heuristics used to
infer that I/Os have begun and completed.  We'll also not look more than
maintenance_io_concurrency * 4 block references ahead.

Reviewed-by: Julien Rouhaud <rjuju123@gmail.com>
Reviewed-by: Tomas Vondra <tomas.vondra@2ndquadrant.com>
Reviewed-by: Alvaro Herrera <alvherre@2ndquadrant.com> (earlier version)
Reviewed-by: Andres Freund <andres@anarazel.de> (earlier version)
Reviewed-by: Justin Pryzby <pryzby@telsasoft.com> (earlier version)
Tested-by: Tomas Vondra <tomas.vondra@2ndquadrant.com> (earlier version)
Tested-by: Jakub Wartak <Jakub.Wartak@tomtom.com> (earlier version)
Tested-by: Dmitry Dolgov <9erthalion6@gmail.com> (earlier version)
Tested-by: Sait Talha Nisanci <Sait.Nisanci@microsoft.com> (earlier version)
Discussion: https://postgr.es/m/CA%2BhUKGJ4VJN8ttxScUFM8dOKX0BrBiboo5uz1cq%3DAovOddfHpA%40mail.gmail.com
2022-04-07 19:42:14 +12:00
Michael Paquier a2c84990be Add system view pg_ident_file_mappings
This view is similar to pg_hba_file_rules view, except that it is
associated with the parsing of pg_ident.conf.  Similarly to its cousin,
this view is useful to check via SQL if changes planned in pg_ident.conf
would work upon reload or restart, or to diagnose a previous failure.

Bumps catalog version.

Author: Julien Rouhaud
Reviewed-by: Aleksander Alekseev, Michael Paquier
Discussion: https://postgr.es/m/20220223045959.35ipdsvbxcstrhya@jrouhaud
2022-03-29 10:15:48 +09:00
Alvaro Herrera 7103ebb7aa
Add support for MERGE SQL command
MERGE performs actions that modify rows in the target table using a
source table or query. MERGE provides a single SQL statement that can
conditionally INSERT/UPDATE/DELETE rows -- a task that would otherwise
require multiple PL statements.  For example,

MERGE INTO target AS t
USING source AS s
ON t.tid = s.sid
WHEN MATCHED AND t.balance > s.delta THEN
  UPDATE SET balance = t.balance - s.delta
WHEN MATCHED THEN
  DELETE
WHEN NOT MATCHED AND s.delta > 0 THEN
  INSERT VALUES (s.sid, s.delta)
WHEN NOT MATCHED THEN
  DO NOTHING;

MERGE works with regular tables, partitioned tables and inheritance
hierarchies, including column and row security enforcement, as well as
support for row and statement triggers and transition tables therein.

MERGE is optimized for OLTP and is parameterizable, though also useful
for large scale ETL/ELT. MERGE is not intended to be used in preference
to existing single SQL commands for INSERT, UPDATE or DELETE since there
is some overhead.  MERGE can be used from PL/pgSQL.

MERGE does not support targetting updatable views or foreign tables, and
RETURNING clauses are not allowed either.  These limitations are likely
fixable with sufficient effort.  Rewrite rules are also not supported,
but it's not clear that we'd want to support them.

Author: Pavan Deolasee <pavan.deolasee@gmail.com>
Author: Álvaro Herrera <alvherre@alvh.no-ip.org>
Author: Amit Langote <amitlangote09@gmail.com>
Author: Simon Riggs <simon.riggs@enterprisedb.com>
Reviewed-by: Peter Eisentraut <peter.eisentraut@enterprisedb.com>
Reviewed-by: Andres Freund <andres@anarazel.de> (earlier versions)
Reviewed-by: Peter Geoghegan <pg@bowt.ie> (earlier versions)
Reviewed-by: Robert Haas <robertmhaas@gmail.com> (earlier versions)
Reviewed-by: Japin Li <japinli@hotmail.com>
Reviewed-by: Justin Pryzby <pryzby@telsasoft.com>
Reviewed-by: Tomas Vondra <tomas.vondra@enterprisedb.com>
Reviewed-by: Zhihong Yu <zyu@yugabyte.com>
Discussion: https://postgr.es/m/CANP8+jKitBSrB7oTgT9CY2i1ObfOt36z0XMraQc+Xrz8QB0nXA@mail.gmail.com
Discussion: https://postgr.es/m/CAH2-WzkJdBuxj9PO=2QaO9-3h3xGbQPZ34kJH=HukRekwM-GZg@mail.gmail.com
Discussion: https://postgr.es/m/20201231134736.GA25392@alvherre.pgsql
2022-03-28 16:47:48 +02:00
Tom Lane ce95c54376 Fix pg_statio_all_tables view for multiple TOAST indexes.
A TOAST table can normally have only one index, but there are corner
cases where it has more; for example, transiently during REINDEX
CONCURRENTLY.  In such a case, the pg_statio_all_tables view produced
multiple rows for the owning table, one per TOAST index.  Refactor the
view to avoid that, instead summing the stats across all the indexes,
as we do for regular table indexes.

While this has been wrong for a long time, back-patching seems unwise
due to the difficulty of putting a system view change into back
branches.

Andrei Zubkov, tweaked a bit by me

Discussion: https://postgr.es/m/acefef4189706971fc475f912c1afdab1c48d627.camel@moonset.ru
2022-03-24 16:33:13 -04:00
Tomas Vondra 75b1521dae Add decoding of sequences to built-in replication
This commit adds support for decoding of sequences to the built-in
replication (the infrastructure was added by commit 0da92dc530).

The syntax and behavior mostly mimics handling of tables, i.e. a
publication may be defined as FOR ALL SEQUENCES (replicating all
sequences in a database), FOR ALL SEQUENCES IN SCHEMA (replicating
all sequences in a particular schema) or individual sequences.

To publish sequence modifications, the publication has to include
'sequence' action. The protocol is extended with a new message,
describing sequence increments.

A new system view pg_publication_sequences lists all the sequences
added to a publication, both directly and indirectly. Various psql
commands (\d and \dRp) are improved to also display publications
including a given sequence, or sequences included in a publication.

Author: Tomas Vondra, Cary Huang
Reviewed-by: Peter Eisentraut, Amit Kapila, Hannu Krosing, Andres
             Freund, Petr Jelinek
Discussion: https://postgr.es/m/d045f3c2-6cfb-06d3-5540-e63c320df8bc@enterprisedb.com
Discussion: https://postgr.es/m/1710ed7e13b.cd7177461430746.3372264562543607781@highgo.ca
2022-03-24 18:49:27 +01:00
Dean Rasheed 7faa5fc84b Add support for security invoker views.
A security invoker view checks permissions for accessing its
underlying base relations using the privileges of the user of the
view, rather than the privileges of the view owner. Additionally, if
any of the base relations are tables with RLS enabled, the policies of
the user of the view are applied, rather than those of the view owner.

This allows views to be defined without giving away additional
privileges on the underlying base relations, and matches a similar
feature available in other database systems.

It also allows views to operate more naturally with RLS, without
affecting the assignments of policies to users.

Christoph Heiss, with some additional hacking by me. Reviewed by
Laurenz Albe and Wolfgang Walther.

Discussion: https://postgr.es/m/b66dd6d6-ad3e-c6f2-8b90-47be773da240%40cybertec.at
2022-03-22 10:28:10 +00:00
Amit Kapila 7a85073290 Reconsider pg_stat_subscription_workers view.
It was decided (refer to the Discussion link below) that the stats
collector is not an appropriate place to store the error information of
subscription workers.

This patch changes the pg_stat_subscription_workers view (introduced by
commit 8d74fc96db) so that it stores only statistics counters:
apply_error_count and sync_error_count, and has one entry for
each subscription. The removed error information such as error-XID and
the error message would be stored in another way in the future which is
more reliable and persistent.

After removing these error details, there is no longer any relation
information, so the subscription statistics are now a cluster-wide
statistics.

The patch also changes the view name to pg_stat_subscription_stats since
the word "worker" is an implementation detail that we use one worker for
one tablesync and one apply.

Author: Masahiko Sawada, based on suggestions by Andres Freund
Reviewed-by: Peter Smith, Haiying Tang, Takamichi Osumi, Amit Kapila
Discussion: https://postgr.es/m/20220125063131.4cmvsxbz2tdg6g65@alap3.anarazel.de
2022-03-01 06:17:52 +05:30
Tom Lane cc50080a82 Rearrange core regression tests to reduce cross-script dependencies.
The idea behind this patch is to make it possible to run individual
test scripts without running the entire core test suite.  Making all
the scripts completely independent would involve a massive rewrite,
and would probably be worse for coverage of things like concurrent DDL.
So this patch just does what seems practical with limited changes.

The net effect is that any test script can be run after running
limited earlier dependencies:
* all scripts depend on test_setup
* many scripts depend on create_index
* other dependencies are few in number, and are documented in
  the parallel_schedule file.

To accomplish this, I chose a small number of commonly-used tables
and moved their creation and filling into test_setup.  Later scripts
are expected not to modify these tables' data contents, for fear of
affecting other scripts' results.  Also, our former habit of declaring
all C functions in one place is now gone in favor of declaring them
where they're used, if that's just one script, or in test_setup if
necessary.

There's more that could be done to remove some of the remaining
inter-script dependencies, but significantly more-invasive changes
would be needed, and at least for now it doesn't seem worth it.

Discussion: https://postgr.es/m/1114748.1640383217@sss.pgh.pa.us
2022-02-08 15:30:38 -05:00
Tomas Vondra 269b532aef Add stxdinherit flag to pg_statistic_ext_data
Add pg_statistic_ext_data.stxdinherit flag, so that for each extended
statistics definition we can store two versions of data - one for the
relation alone, one for the whole inheritance tree. This is analogous to
pg_statistic.stainherit, but we failed to include such flag in catalogs
for extended statistics, and we had to work around it (see commits
859b3003de, 36c4bc6e72 and 20b9fa308e).

This changes the relationship between the two catalogs storing extended
statistics objects (pg_statistic_ext and pg_statistic_ext_data). Until
now, there was a simple 1:1 mapping - for each definition there was one
pg_statistic_ext_data row, and this row was inserted while creating the
statistics (and then updated during ANALYZE). With the stxdinherit flag,
we don't know how many rows there will be (child relations may be added
after the statistics object is defined), so there may be up to two rows.

We could make CREATE STATISTICS to always create both rows, but that
seems wasteful - without partitioning we only need stxdinherit=false
rows, and declaratively partitioned tables need only stxdinherit=true.
So we no longer initialize pg_statistic_ext_data in CREATE STATISTICS,
and instead make that a responsibility of ANALYZE. Which is what we do
for regular statistics too.

Patch by me, with extensive improvements and fixes by Justin Pryzby.

Author: Tomas Vondra, Justin Pryzby
Reviewed-by: Tomas Vondra, Justin Pryzby
Discussion: https://postgr.es/m/20210923212624.GI831%40telsasoft.com
2022-01-16 13:38:01 +01:00
Amit Kapila 8d74fc96db Add a view to show the stats of subscription workers.
This commit adds a new system view pg_stat_subscription_workers, that
shows information about any errors which occur during the application of
logical replication changes as well as during performing initial table
synchronization. The subscription statistics entries are removed when the
corresponding subscription is removed.

It also adds an SQL function pg_stat_reset_subscription_worker() to reset
single subscription errors.

The contents of this view can be used by an upcoming patch that skips the
particular transaction that conflicts with the existing data on the
subscriber.

This view can be extended in the future to track other xact related
statistics like the number of xacts committed/aborted for subscription
workers.

Author: Masahiko Sawada
Reviewed-by: Greg Nancarrow, Hou Zhijie, Tang Haiying, Vignesh C, Dilip Kumar, Takamichi Osumi, Amit Kapila
Discussion: https://postgr.es/m/CAD21AoDeScrsHhLyEPYqN3sydg6PxAPVBboK=30xJfUVihNZDA@mail.gmail.com
2021-11-30 08:54:30 +05:30
Tom Lane 8d2d6ec770 Avoid trying to lock OLD/NEW in a rule with FOR UPDATE.
transformLockingClause neglected to exclude the pseudo-RTEs for
OLD/NEW when processing a rule's query.  This led to odd errors
or even crashes later on.  This bug is very ancient, but it's
not terribly surprising that nobody noticed, since the use-case
for SELECT FOR UPDATE in a non-view rule is somewhere between
thin and non-existent.  Still, crashing is not OK.

Per bug #17151 from Zhiyong Wu.  Thanks to Masahiko Sawada
for analysis of the problem.

Discussion: https://postgr.es/m/17151-c03a3e6e4ec9aadb@postgresql.org
2021-08-19 12:12:35 -04:00
Thomas Munro c2dc19342e Revert recovery prefetching feature.
This set of commits has some bugs with known fixes, but at this late
stage in the release cycle it seems best to revert and resubmit next
time, along with some new automated test coverage for this whole area.

Commits reverted:

dc88460c: Doc: Review for "Optionally prefetch referenced data in recovery."
1d257577: Optionally prefetch referenced data in recovery.
f003d9f8: Add circular WAL decoding buffer.
323cbe7c: Remove read_page callback from XLogReader.

Remove the new GUC group WAL_RECOVERY recently added by a55a9847, as the
corresponding section of config.sgml is now reverted.

Discussion: https://postgr.es/m/CAOuzzgrn7iKnFRsB4MHp3UisEQAGgZMbk_ViTN4HV4-Ksq8zCg%40mail.gmail.com
2021-05-10 16:06:09 +12:00
Amit Kapila 3fa17d3771 Use HTAB for replication slot statistics.
Previously, we used to use the array of size max_replication_slots to
store stats for replication slots. But that had two problems in the cases
where a message for dropping a slot gets lost: 1) the stats for the new
slot are not recorded if the array is full and 2) writing beyond the end
of the array if the user reduces the max_replication_slots.

This commit uses HTAB for replication slot statistics, resolving both
problems. Now, pgstat_vacuum_stat() search for all the dead replication
slots in stats hashtable and tell the collector to remove them. To avoid
showing the stats for the already-dropped slots, pg_stat_replication_slots
view searches slot stats by the slot name taken from pg_replication_slots.

Also, we send a message for creating a slot at slot creation, initializing
the stats. This reduces the possibility that the stats are accumulated
into the old slot stats when a message for dropping a slot gets lost.

Reported-by: Andres Freund
Author: Sawada Masahiko, test case by Vignesh C
Reviewed-by: Amit Kapila, Vignesh C, Dilip Kumar
Discussion: https://postgr.es/m/20210319185247.ldebgpdaxsowiflw@alap3.anarazel.de
2021-04-27 09:09:11 +05:30
Bruce Momjian 9660834dd8 adjust query id feature to use pg_stat_activity.query_id
Previously, it was pg_stat_activity.queryid to match the
pg_stat_statements queryid column.  This is an adjustment to patch
4f0b0966c8.  This also adjusts some of the internal function calls to
match.  Catversion bumped.

Reported-by: Álvaro Herrera, Julien Rouhaud

Discussion: https://postgr.es/m/20210408032704.GA7498@alvherre.pgsql
2021-04-20 12:22:26 -04:00
Amit Kapila f5fc2f5b23 Add information of total data processed to replication slot stats.
This adds the statistics about total transactions count and total
transaction data logically sent to the decoding output plugin from
ReorderBuffer. Users can query the pg_stat_replication_slots view to check
these stats.

Suggested-by: Andres Freund
Author: Vignesh C and Amit Kapila
Reviewed-by: Sawada Masahiko, Amit Kapila
Discussion: https://postgr.es/m/20210319185247.ldebgpdaxsowiflw@alap3.anarazel.de
2021-04-16 07:34:43 +05:30
Thomas Munro 1d257577e0 Optionally prefetch referenced data in recovery.
Introduce a new GUC recovery_prefetch, disabled by default.  When
enabled, look ahead in the WAL and try to initiate asynchronous reading
of referenced data blocks that are not yet cached in our buffer pool.
For now, this is done with posix_fadvise(), which has several caveats.
Better mechanisms will follow in later work on the I/O subsystem.

The GUC maintenance_io_concurrency is used to limit the number of
concurrent I/Os we allow ourselves to initiate, based on pessimistic
heuristics used to infer that I/Os have begun and completed.

The GUC wal_decode_buffer_size is used to limit the maximum distance we
are prepared to read ahead in the WAL to find uncached blocks.

Reviewed-by: Alvaro Herrera <alvherre@2ndquadrant.com> (parts)
Reviewed-by: Andres Freund <andres@anarazel.de> (parts)
Reviewed-by: Tomas Vondra <tomas.vondra@2ndquadrant.com> (parts)
Tested-by: Tomas Vondra <tomas.vondra@2ndquadrant.com>
Tested-by: Jakub Wartak <Jakub.Wartak@tomtom.com>
Tested-by: Dmitry Dolgov <9erthalion6@gmail.com>
Tested-by: Sait Talha Nisanci <Sait.Nisanci@microsoft.com>
Discussion: https://postgr.es/m/CA%2BhUKGJ4VJN8ttxScUFM8dOKX0BrBiboo5uz1cq%3DAovOddfHpA%40mail.gmail.com
2021-04-08 23:20:42 +12:00
Alvaro Herrera 0827e8af70
autovacuum: handle analyze for partitioned tables
Previously, autovacuum would completely ignore partitioned tables, which
is not good regarding analyze -- failing to analyze those tables means
poor plans may be chosen.  Make autovacuum aware of those tables by
propagating "changes since analyze" counts from the leaf partitions up
the partitioning hierarchy.

This also introduces necessary reloptions support for partitioned tables
(autovacuum_enabled, autovacuum_analyze_scale_factor,
autovacuum_analyze_threshold).  It's unclear how best to document this
aspect.

Author: Yuzuko Hosoya <yuzukohosoya@gmail.com>
Reviewed-by: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Reviewed-by: Tomas Vondra <tomas.vondra@enterprisedb.com>
Reviewed-by: Álvaro Herrera <alvherre@alvh.no-ip.org>
Discussion: https://postgr.es/m/CAKkQ508_PwVgwJyBY=0Lmkz90j8CmWNPUxgHvCUwGhMrouz6UA@mail.gmail.com
2021-04-08 01:19:36 -04:00
Bruce Momjian 4f0b0966c8 Make use of in-core query id added by commit 5fd9dfa5f5
Use the in-core query id computation for pg_stat_activity,
log_line_prefix, and EXPLAIN VERBOSE.

Similar to other fields in pg_stat_activity, only the queryid from the
top level statements are exposed, and if the backends status isn't
active then the queryid from the last executed statements is displayed.

Add a %Q placeholder to include the queryid in log_line_prefix, which
will also only expose top level statements.

For EXPLAIN VERBOSE, if a query identifier has been computed, either by
enabling compute_query_id or using a third-party module, display it.

Bump catalog version.

Discussion: https://postgr.es/m/20210407125726.tkvjdbw76hxnpwfi@nol

Author: Julien Rouhaud

Reviewed-by: Alvaro Herrera, Nitin Jadhav, Zhihong Yu
2021-04-07 14:04:06 -04:00
Tomas Vondra a4d75c86bf Extended statistics on expressions
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
2021-03-27 00:01:11 +01:00
Fujii Masao ff99918c62 Track total amounts of times spent writing and syncing WAL data to disk.
This commit adds new GUC track_wal_io_timing. When this is enabled,
the total amounts of time XLogWrite writes and issue_xlog_fsync syncs
WAL data to disk are counted in pg_stat_wal. This information would be
useful to check how much WAL write and sync affect the performance.

Enabling track_wal_io_timing will make the server query the operating
system for the current time every time WAL is written or synced,
which may cause significant overhead on some platforms. To avoid such
additional overhead in the server with track_io_timing enabled,
this commit introduces track_wal_io_timing as a separate parameter from
track_io_timing.

Note that WAL write and sync activity by walreceiver has not been tracked yet.

This commit makes the server also track the numbers of times XLogWrite
writes and issue_xlog_fsync syncs WAL data to disk, in pg_stat_wal,
regardless of the setting of track_wal_io_timing. This counters can be
used to calculate the WAL write and sync time per request, for example.

Bump PGSTAT_FILE_FORMAT_ID.

Bump catalog version.

Author: Masahiro Ikeda
Reviewed-By: Japin Li, Hayato Kuroda, Masahiko Sawada, David Johnston, Fujii Masao
Discussion: https://postgr.es/m/0509ad67b585a5b86a83d445dfa75392@oss.nttdata.com
2021-03-09 16:52:06 +09:00
Michael Paquier 9d2d457009 Add support for more progress reporting in COPY
The command (TO or FROM), its type (file, pipe, program or callback),
and the number of tuples excluded by a WHERE clause in COPY FROM are
added to the progress reporting already available.

The column "lines_processed" is renamed to "tuples_processed" to
disambiguate the meaning of this column in the cases of CSV and BINARY
COPY and to be more consistent with the other catalog progress views.

Bump catalog version, again.

Author: Matthias van de Meent
Reviewed-by: Michael Paquier, Justin Pryzby, Bharath Rupireddy, Josef
Šimánek, Tomas Vondra
Discussion: https://postgr.es/m/CAEze2WiOcgdH4aQA8NtZq-4dgvnJzp8PohdeKchPkhMY-jWZXA@mail.gmail.com
2021-03-09 14:21:03 +09:00
Michael Paquier f9264d1524 Remove support for SSL compression
PostgreSQL disabled compression as of e3bdb2d and the documentation
recommends against using it since.  Additionally, SSL compression has
been disabled in OpenSSL since version 1.1.0, and was disabled in many
distributions long before that.  The most recent TLS version, TLSv1.3,
disallows compression at the protocol level.

This commit removes the feature itself, removing support for the libpq
parameter sslcompression (parameter still listed for compatibility
reasons with existing connection strings, just ignored), and removes
the equivalent field in pg_stat_ssl and de facto PgBackendSSLStatus.

Note that, on top of removing the ability to activate compression by
configuration, compression is actively disabled in both frontend and
backend to avoid overrides from local configurations.

A TAP test is added for deprecated SSL parameters to check after
backwards compatibility.

Bump catalog version.

Author: Daniel Gustafsson
Reviewed-by: Peter Eisentraut, Magnus Hagander, Michael Paquier
Discussion:  https://postgr.es/m/7E384D48-11C5-441B-9EC3-F7DB1F8518F6@yesql.se
2021-03-09 11:16:47 +09:00
Amit Kapila 19890a064e Add option to enable two_phase commits via pg_create_logical_replication_slot.
Commit 0aa8a01d04 extends the output plugin API to allow decoding of
prepared xacts and allowed the user to enable/disable the two-phase option
via pg_logical_slot_get_changes(). This can lead to a problem such that
the first time when it gets changes via pg_logical_slot_get_changes()
without two_phase option enabled it will not get the prepared even though
prepare is after consistent snapshot. Now next time during getting changes,
if the two_phase option is enabled it can skip prepare because by that
time start decoding point has been moved. So the user will only get commit
prepared.

Allow to enable/disable this option at the create slot time and default
will be false. It will break the existing slots which is fine in a major
release.

Author: Ajin Cherian
Reviewed-by: Amit Kapila and Vignesh C
Discussion: https://postgr.es/m/d0f60d60-133d-bf8d-bd70-47784d8fabf3@enterprisedb.com
2021-03-03 07:34:11 +05:30
Fujii Masao 46d6e5f567 Display the time when the process started waiting for the lock, in pg_locks, take 2
This commit adds new column "waitstart" into pg_locks view. This column
reports the time when the server process started waiting for the lock
if the lock is not held. This information is useful, for example, when
examining the amount of time to wait on a lock by subtracting
"waitstart" in pg_locks from the current time, and identify the lock
that the processes are waiting for very long.

This feature uses the current time obtained for the deadlock timeout
timer as "waitstart" (i.e., the time when this process started waiting
for the lock). Since getting the current time newly can cause overhead,
we reuse the already-obtained time to avoid that overhead.

Note that "waitstart" is updated without holding the lock table's
partition lock, to avoid the overhead by additional lock acquisition.
This can cause "waitstart" in pg_locks to become NULL for a very short
period of time after the wait started even though "granted" is false.
This is OK in practice because we can assume that users are likely to
look at "waitstart" when waiting for the lock for a long time.

The first attempt of this patch (commit 3b733fcd04) caused the buildfarm
member "rorqual" (built with --disable-atomics --disable-spinlocks) to report
the failure of the regression test. It was reverted by commit 890d2182a2.
The cause of this failure was that the atomic variable for "waitstart"
in the dummy process entry created at the end of prepare transaction was
not initialized. This second attempt fixes that issue.

Bump catalog version.

Author: Atsushi Torikoshi
Reviewed-by: Ian Lawrence Barwick, Robert Haas, Justin Pryzby, Fujii Masao
Discussion: https://postgr.es/m/a96013dc51cdc56b2a2b84fa8a16a993@oss.nttdata.com
2021-02-15 15:13:37 +09:00
Fujii Masao 890d2182a2 Revert "Display the time when the process started waiting for the lock, in pg_locks."
This reverts commit 3b733fcd04.

Per buildfarm members prion and rorqual.
2021-02-09 18:30:40 +09:00