This patch adds 'stats_since' and 'minmax_stats_since' columns to the
pg_stat_statements view and pg_stat_statements() function. The new min/max
reset mode for the pg_stat_stetments_reset() function is controlled by the
parameter minmax_only.
'stat_since' column is populated with the current timestamp when a new
statement is added to the pg_stat_statements hashtable. It provides clean
information about statistics collection time intervals for each statement.
Besides it can be used by sampling solutions to detect situations when a
statement was evicted and stored again between samples.
Such a sampling solution could derive any pg_stat_statements statistic values
for an interval between two samples with the exception of all min/max
statistics. To address this issue this patch adds the ability to reset
min/max statistics independently of the statement reset using the new
minmax_only parameter of the pg_stat_statements_reset(userid oid, dbid oid,
queryid bigint, minmax_only boolean) function. The timestamp of such reset
is stored in the minmax_stats_since field for each statement.
pg_stat_statements_reset() function now returns the timestamp of a reset as the
result.
Discussion: https://postgr.es/m/flat/72e80e7b160a6eb189df9ef6f068cce3765d37f8.camel%40moonset.ru
Author: Andrei Zubkov
Reviewed-by: Julien Rouhaud, Hayato Kuroda, Yuki Seino, Chengxi Sun
Reviewed-by: Anton Melnikov, Darren Rush, Michael Paquier, Sergei Kornilov
Reviewed-by: Alena Rybakina, Andrei Lepikhov
This is preliminary patch. It adds NOT NULL checking for the result of
pg_stat_statements_reset() function. It is needed for upcoming patch
"Track statement entry timestamp" that will change the result type of
this function to the timestamp of a reset performed.
Discussion: https://postgr.es/m/flat/72e80e7b160a6eb189df9ef6f068cce3765d37f8.camel%40moonset.ru
Author: Andrei Zubkov
Reviewed-by: Julien Rouhaud, Hayato Kuroda, Yuki Seino, Chengxi Sun
Reviewed-by: Anton Melnikov, Darren Rush, Michael Paquier, Sergei Kornilov
Reviewed-by: Alena Rybakina, Andrei Lepikhov
When we decide that we don't want to track execution time of a
specific planner or ProcessUtility call, we still have to increment
the nesting depth, or we'll make the wrong determination of whether
we are at top level when considering nested statements. (PREPARE
and EXECUTE are exceptions, for reasons explained in the code.)
Counting planner nesting depth separately from executor nesting depth
was a mistake: it causes us to make the wrong determination of whether
we are at top level when considering nested statements that get
executed during planning (as a result of constant-folding of
functions, for example). Merge those counters into one.
In passing, get rid of the PGSS_HANDLED_UTILITY macro in favor of
explicitly listing statement types. It seems somewhat coincidental
that PREPARE and EXECUTE are handled alike in each of the places where
that was used: the reasoning tends to be different for each one.
Thus, the macro seems as likely to encourage future bugs as prevent
them, since it's quite unclear whether any future statement type that
might need special-casing here would also need the same choices at
each spot.
Sergei Kornilov, Julien Rouhaud, and Tom Lane, per bug #17552 from
Maxim Boguk. This is pretty clearly a bug fix, but it's also a
behavioral change that might surprise somebody, so no back-patch.
Discussion: https://postgr.es/m/17552-213b534c56ab5d02@postgresql.org
This commit adds to pg_stat_statements the two new fields for local
buffers introduced by 295c36c0c1, adding the time spent to read and
write these blocks. These are similar to what is done for temp and
shared blocks. This information available only if track_io_timing is
enabled.
Like for 5a3423ad8e, no version bump is required in the module.
Author: Nazir Bilal Yavuz
Reviewed-by: Robert Haas, Melanie Plageman
Discussion: https://postgr.es/m/CAN55FZ19Ss279mZuqGbuUNxka0iPbLgYuOQXqAKewrjNrp27VA@mail.gmail.com
These two counters, defined in BufferUsage to track respectively the
time spent while reading and writing blocks have historically only
tracked data related to shared buffers, when track_io_timing is enabled.
An upcoming patch to add specific counters for local buffers will take
advantage of this rename as it has come up that no data is currently
tracked for local buffers, and tracking local and shared buffers using
the same fields would be inconsistent with the treatment done for temp
buffers. Renaming the existing fields clarifies what the block type of
each stats field is.
pg_stat_statement is updated to reflect the rename. No extension
version bump is required as 5a3423ad8e has done one, affecting v17~.
Author: Nazir Bilal Yavuz
Reviewed-by: Robert Haas, Melanie Plageman
Discussion: https://postgr.es/m/CAN55FZ19Ss279mZuqGbuUNxka0iPbLgYuOQXqAKewrjNrp27VA@mail.gmail.com
This commit changes the query jumbling of CallStmt so as its IN/OUT
parameters are able to show up as constants with a parameter symbol in
pg_stat_statements, like:
CALL proc1($1, $2);
CALL proc2($1, $2, $3);
The transformed FuncExpr is used in the query ID computation instead of
the FuncCall generated by the parser, so as it is sensitive to the OID
of the procedure and its list of input arguments. The output arguments
are handled in a separate list in CallStmt, which is also included in
the computation.
Tests are added to pg_stat_statements to show how this affects CALL with
IN/OUT parameters as well as overloaded functions.
Like 638d42a3c5 or 31de7e60da, this improves the monitoring of
workloads with a lot of CALL statements, preventing unnecessary bloat
when these use different input (or event output) values.
Author: Sami Imseih
Discussion: https://postgr.es/m/B44FA29D-EBD0-4DD9-ABC2-16F1CB087074@amazon.com
Karina figured out that I (Andres) confused BufferUsage.temp_blks_written with
BufferUsage.local_blks_written in fcdda1e4b5.
Tests in core PG can't easily test this, as BufferUsage is just used for
EXPLAIN (ANALYZE, BUFFERS) and pg_stat_statements. Thus this commit adds tests
for this to pg_stat_statements.
Reported-by: Karina Litskevich <litskevichkarina@gmail.com>
Author: Karina Litskevich <litskevichkarina@gmail.com>
Author: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/CACiT8ibxXA6+0amGikbeFhm8B84XdQVo6D0Qfd1pQ1s8zpsnxQ@mail.gmail.com
Backpatch: 16-, where fcdda1e4b5 was merged
This commit switches query jumbling so as prepared statement names are
treated as constants in DeallocateStmt. A boolean field is added to
DeallocateStmt to make a distinction between ALL and named prepared
statements, as "name" was used to make this difference before, NULL
meaning DEALLOCATE ALL.
Prior to this commit, DEALLOCATE was not tracked in pg_stat_statements,
for the reason that it was not possible to treat its name parameter as a
constant. Now that query jumbling applies to all the utility nodes,
this reason does not apply anymore.
Like 638d42a3c5, this can be a huge advantage for monitoring where
prepared statement names are randomly generated, preventing bloat in
pg_stat_statements. A couple of tests are added to track the new
behavior.
Author: Dagfinn Ilmari Mannsåker, Michael Paquier
Reviewed-by: Julien Rouhaud
Discussion: https://postgr.es/m/ZMhT9kNtJJsHw6jK@paquier.xyz
This relies on the "location" field added to TransactionStmt in 31de7e6,
now applied to the "gid" field used by 2PC commands. These commands are
now reported like:
COMMIT PREPARED $1
PREPARE TRANSACTION $1
ROLLBACK PREPARED $1
Applying constants for these commands is a huge advantage for workloads
that rely a lot on 2PC commands with different GIDs. Some tests are
added to track the new behavior.
Reviewed-by: Julien Rouhaud
Discussion: https://postgr.es/m/ZMhT9kNtJJsHw6jK@paquier.xyz
In pg_stat_statements, savepoint names now show up as constants with a
parameter symbol, using as base query string the one added as a new
entry to the PGSS hash table, leading to:
RELEASE $1
ROLLBACK TO $1
SAVEPOINT $1
Applying constants to these query parts is a huge advantage for
workloads that generate randomly savepoint points, like ORMs (Django is
at the origin of this patch). The ODBC driver is a second layer that
likes a lot savepoints, though it does not use a random naming pattern.
A "location" field is added to TransactionStmt, now set only for
savepoints. The savepoint name is ignored by the query jumbling. The
location can be extended to other query patterns, if required, like 2PC
commands. Some tests are added to pg_stat_statements for all the query
patterns supported by the parser.
ROLLBACK, ROLLBACK TO SAVEPOINT and ROLLBACK TRANSACTION TO SAVEPOINT
have the same Node representation, so all these are equivalents. The
same happens for RELEASE and RELEASE SAVEPOINT.
Author: Greg Sabino Mullane
Discussion: https://postgr.es/m/CAKAnmm+2s9PA4OaumwMJReWHk8qvJ_-g1WqxDRDAN1BSUfxyTw@mail.gmail.com
Applying normalization changes how the following query strings are
reflected in pg_stat_statements, by showing Const nodes with a
dollar-signed parameter as this is how such queries are structured
internally once parsed:
- DECLARE
- EXPLAIN
- CREATE MATERIALIZED VIEW
- CREATE TABLE AS
More normalization could be done in the future depending on the parts
where query jumbling is applied (like A_Const nodes?), the changes being
reflected in the regression tests in majority created in de2aca2. This
just allows the basics to work for utility queries using Const nodes.
Reviewed-by: Bertrand Drouvot
Discussion: https://postgr.es/m/Y+MRdEq9W9XVa2AB@paquier.xyz
As shaped, two DROP ROLE queries included in "user_activity" were
showing in the reports for "wal". The intention is to keep each test
isolated and independent, so this is incorrect. This commit adds some
calls to pg_stat_statements_reset() to clean up the statistics once each
test finishes, so as there are no risks of overlap in the reports for
individial scenarios.
The addition in "user_activity" fixes the output of "wal". The new
resets done in "level_tracking" and "utility" are added for consistency
with the rest, though they do not affect the stats generated in the
other tests.
Oversight in d0028e3.
Reported-by: Andrei Zubkov
Discussion: https://postgr.es/m/7beb722dd016bf54f1c78bfd6d44a684e28da624.camel@moonset.ru
This commit expands more the refactoring of the regression tests of
pg_stat_statements, with tests moved out of pg_stat_statements.sql into
separate files. The following file structure is now used:
- select is mostly the former pg_stat_statements.sql, renamed.
- dml for INSERT/UPDATE/DELETE and MERGE
- user_activity, to test role-level checks and stat resets.
- wal, to check the WAL generation after some queries.
Like e8dbdb1, there is no change in terms of code coverage or results,
and this finishes the split I was aiming for in these tests. Most of
the tests used "test" of "pgss_test" as names for the tables used, these
are renamed to less generic names.
Reviewed-by: Bertrand Drouvot
Discussion: https://postgr.es/m/Y/7Y9U/y/keAW3qH@paquier.xyz
This commit adds more coverage for utility statements so as it is
possible to track down all the effects of query normalization done for
all the queries that use either Const or A_Const nodes, which are the
nodes where normalization makes the most sense as they apply to
constants (well, most of the time, really).
This set of queries is extracted from an analysis done while looking at
full dumps of the regression database when applying different levels of
normalization to either Const or A_Const nodes for utilities, as of a
minimal set of these, for:
- All relkinds (CREATE, ALTER, DROP)
- Policies
- Cursors
- Triggers
- Types
- Rules
- Statistics
- CALL
- Transaction statements (isolation level, options)
- EXPLAIN
- COPY
Note that pg_stat_statements is not switched yet to show any
normalization for utilities, still it improves the default coverage of
the query jumbling code (not by as much as enabling query jumbling on
the main regression test suite, though):
- queryjumblefuncs.funcs.c: 36.8% => 48.5%
- queryjumblefuncs.switch.c: 33.2% => 43.1%
Reviewed-by: Bertrand Drouvot
Discussion: https://postgr.es/m/Y+MRdEq9W9XVa2AB@paquier.xyz
pg_stat_statements.sql acts as the main file for all the core tests of
the module, but things have become complicated to follow over the years
as some of the sub-scenarios tested in this file rely on assumptions
that come from completely different areas of it, like a GUC setup or a
relation created previously. For example, row tracking for CTAS/COPY
was looking at the number of plans, which was not necessary, or level
tracking was mixed with checks on planner counts.
This commit refactors the tests of pg_stat_statements, by moving test
cases out of pg_stat_statements.sql into their own file, as of:
- Planning-related tests in planning.sql, for [re]plan counts and
top-level handling. These depend on pg_stat_statements.track_planning.
- Utilities in utility.sql (pg_stat_statements.track_utility), that
includes now the tests for:
-- Row tracking for CTAS, CREATE MATERIALIZED VIEW, COPY.
-- Basic utility statements.
-- SET statements.
- Tracking level, depending on pg_stat_statements.track. This part has
been looking at scenarios with DO blocks, PL functions and SQL
functions.
pg_stat_statements.sql (still named the same for now) still includes
some checks for role-level tracking and WAL generation metrics, that
ought to become independent in the long term for clarity.
While on it, this switches the order of the attributes when querying
pg_stat_statements, the query field becoming last. This makes much
easier the tracking of changes related to normalization, as queries are
the only variable-length attributes queried (unaligned mode would be one
extra choice, but that reduces the checks on the other fields).
Test scenarios and their results match exactly with what was happening
before this commit in terms of calls, number of plans, number of rows,
cached data or level tracking, so this has no effect on the coverage in
terms of what is produced by the reports in the table
pg_stat_statements. A follow-up patch will extend more the tests of
pg_stat_statements around utilities, so this split creates a foundation
for this purpose, without complicating more pg_stat_statements.sql.
Reviewed-by: Bertrand Drouvot
Discussion: https://postgr.es/m/Y+MRdEq9W9XVa2AB@paquier.xyz
Like the implementation for node copy, write and read, this node
requires a custom implementation so as the query jumbling is able to
consider the correct value assigned to it, depending on its type (int,
float, bool, string, bitstring).
Based on a dump of pg_stat_statements from the regression database, this
would confuse the query jumbling of the following queries:
- SET.
- COPY TO with SELECT queries.
- START TRANSACTION with different isolation levels.
- ALTER TABLE with default expressions.
- CREATE TABLE with partition bounds.
Note that there may be a long-term argument in tracking the location of
such nodes so as query strings holding such nodes could be normalized,
but this is left as a separate discussion.
Oversight in 3db72eb.
Discussion: https://postgr.es/m/Y9+HuYslMAP6yyPb@paquier.xyz
This commit changes the query jumbling code in queryjumblefuncs.c to be
generated automatically based on the information of the nodes in the
headers of src/include/nodes/ by using gen_node_support.pl. This
approach offers many advantages:
- Support for query jumbling for all the utility statements, based on the
state of their parsed Nodes and not only their query string. This will
greatly ease the switch to normalize the information of some DDLs, like
SET or CALL for example (this is left unchanged and should be part of a
separate discussion). With this feature, the number of entries stored
for utilities in pg_stat_statements is reduced (for example now
"CHECKPOINT" and "checkpoint" mean the same thing with the same query
ID).
- Documentation of query jumbling directly in the structure definition
of the nodes. Since this code has been introduced in pg_stat_statements
and then moved to code, the reasons behind the choices of what should be
included in the jumble are rather sparse. Note that some explanation is
added for the most relevant parts, as a start.
- Overall code reduction and more consistency with the other parts
generating read, write and copy depending on the nodes.
The query jumbling is controlled by a couple of new node attributes,
documented in nodes/nodes.h:
- custom_query_jumble, to mark a Node as having a custom
implementation.
- no_query_jumble, to ignore entirely a Node.
- query_jumble_ignore, to ignore a field in a Node.
- query_jumble_location, to mark a location in a Node, for
normalization. This can apply only to int fields, with "location" in
their name (only Const as of this commit).
There should be no compatibility impact on pg_stat_statements, as the
new code applies the jumbling to the same fields for each node (its
regression tests have no modification, for one).
Some benchmark of the query jumbling between HEAD and this commit for
SELECT and DMLs has proved that this new code does not cause a
performance regression, with computation times close for both methods.
For utility queries, the new method is slower than the previous method
of calculating a hash of the query string, though we are talking about
extra ns-level changes based on what I measured, which is unnoticeable
even for OLTP workloads as a query ID is calculated once per query
post-parse analysis.
Author: Michael Paquier
Reviewed-by: Peter Eisentraut
Discussion: https://postgr.es/m/Y5BHOUhX3zTH/ig6@paquier.xyz
We weren't jumbling the merge action list, so wildly different commands
would be considered to use the same query ID. Add that, mention it in
the docs, and some test lines.
Backpatch to 15.
Author: Tatsu <bt22nakamorit@oss.nttdata.com>
Reviewed-by: Julien Rouhaud <rjuju123@gmail.com>
Discussion: https://postgr.es/m/d87e391694db75a038abc3b2597828e8@oss.nttdata.com
It's not very robust to assume that each inserted row will produce
exactly one WAL record and that no other WAL records will be generated
in the process, because for example a particular transaction could
always be the one that has to extend clog.
Because these tests are not run by 'make installcheck' but only by
'make check', it may be that in our current testing infrastructure
this can't be hit, but it doesn't seem like a good idea to rely on
that, since unrelated changes to the regression tests or the way
write-ahead logging is done could easily cause it to start happening,
and debugging such failures is a pain.
Adjust the regression test to be less sensitive.
Anton Melnikov, reviewed by Julien Rouhaud
Discussion: http://postgr.es/m/1ccd00d9-1723-6b68-ae56-655aab00d406@inbox.ru
This commit adds two new columns to pg_stat_statements, called
temp_blk_read_time and temp_blk_write_time. Those columns respectively
show the time spent to read and write temporary file blocks on disk,
whose tracking has been added in efb0ef9. This information is
available when track_io_timing is enabled, like blk_read_time and
blk_write_time.
pg_stat_statements is updated to version to 1.10 as an effect of the
newly-added columns. Tests for the upgrade path 1.9->1.10 are added.
PGSS_FILE_HEADER is bumped for the new stats file format.
Author: Masahiko Sawada
Reviewed-by: Georgios Kokolatos, Melanie Plageman, Julien Rouhaud,
Ranier Vilela
Discussion: https://postgr.es/m/CAD21AoAJgotTeP83p6HiAGDhs_9Fw9pZ2J=_tYTsiO5Ob-V5GQ@mail.gmail.com
Previously, psql printed only the last result if a command string
returned multiple result sets. Now it prints all of them. The
previous behavior can be obtained by setting the psql variable
SHOW_ALL_RESULTS to off.
This is a significantly enhanced version of
3a51306722 (that was later reverted).
There is also much more test coverage for various psql features now.
Author: Fabien COELHO <coelho@cri.ensmp.fr>
Reviewed-by: Peter Eisentraut <peter.eisentraut@enterprisedb.com>
Reviewed-by: "Iwata, Aya" <iwata.aya@jp.fujitsu.com> (earlier version)
Reviewed-by: Daniel Verite <daniel@manitou-mail.org> (earlier version)
Reviewed-by: Kyotaro Horiguchi <horikyota.ntt@gmail.com> (earlier version)
Reviewed-by: vignesh C <vignesh21@gmail.com> (earlier version)
Discussion: https://www.postgresql.org/message-id/flat/alpine.DEB.2.21.1904132231510.8961@lancre
psql's lexer has historically deleted dash-dash (single-line) comments
from what's collected and sent to the server. This is inconsistent
with what it does for slash-star comments, and people have complained
before that they wish such comments would be captured in the server log.
Undoing the decision completely seems like too big a behavioral change,
however. In particular, comments on lines preceding the start of a
query are generally not thought of as being part of that query.
What we can do to improve the situation is to capture comments that
are clearly *within* a query, that is after the first non-whitespace,
non-comment token but before the query's ending semicolon or backslash
command. This is a nearly trivial code change, and it affects only a
few regression test results.
(It is tempting to try to apply the same rule to slash-star comments.
But it's hard to see how to do that without getting strange history
behavior for comments that cross lines, especially if the user then
starts a new query on the same line as the star-slash. In view of
the lack of complaints, let's leave that case alone.)
Discussion: https://postgr.es/m/CAJcOf-cAdMVr7azeYR7nWKsNp7qhORzc84rV6d7m7knG5Hrtsw@mail.gmail.com
When the newest version is loaded, the backend would load objects from
the oldest complete SQL file (here 1.4) and then update to the latest
version with transition scripts (up to 1.9 currently). This provides
some coverage for upgrades of pg_stat_statements, but there is no test
to show how things have changed across each version.
This adds a couple of tests for the upgrade paths using objects from
each version supported, stressing the objects whose behaviors have
changed across each version supported.
Author: Erica Zhang
Reviewed-by: Julien Rouhaud, Michael Paquier
Discussion: https://postgr.es/m/tencent_BBA974AFF61379F2345E782FD6C55891950A@qq.com
Properly fix:
- the "ONLY" in FROM [ONLY] isn't hashed
- the agglevelsup field in GROUPING isn't hashed
- WITH TIES not being hashed (new in PG 13)
- "DISTINCT" in "GROUP BY [DISTINCT]" isn't hashed (new in PG 14)
Reported-by: Julien Rouhaud
Discussion: https://postgr.es/m/20210425081119.ulyzxqz23ueh3wuj@nol
Changing pg_stat_statements.track between 'all' and 'top' would control
if pg_stat_statements tracked just top level statements or also
statements inside functions, but when tracking all it would not
differentiate between the two. Being table to differentiate this is
useful both to track where the actual query is coming from, and to see
if there are differences in executions between the two.
To do this, add a boolean to the hash key indicating if the statement
was top level or not.
Experience from the pg_stat_kcache module shows that in at least some
"reasonable worloads" only <5% of the queries show up both top level and
nested. Based on this, admittedly small, dataset, this patch does not
try to de-duplicate those query *texts*, and will just store one copy
for the top level and one for the nested.
Author: Julien Rohaud
Reviewed-By: Magnus Hagander, Masahiro Ikeda
Discussion: https://postgr.es/m/20201202040516.GA43757@nol
Previously, psql printed only the last result if a command string
returned multiple result sets. Now it prints all of them. The
previous behavior can be obtained by setting the psql variable
SHOW_ALL_RESULTS to off.
Author: Fabien COELHO <coelho@cri.ensmp.fr>
Reviewed-by: "Iwata, Aya" <iwata.aya@jp.fujitsu.com>
Reviewed-by: Daniel Verite <daniel@manitou-mail.org>
Reviewed-by: Peter Eisentraut <peter.eisentraut@2ndquadrant.com>
Reviewed-by: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Reviewed-by: vignesh C <vignesh21@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/alpine.DEB.2.21.1904132231510.8961@lancre
If more distinct statements than pg_stat_statements.max are observed,
pg_stat_statements entries about the least-executed statements are
deallocated. This commit enables us to track the total number of times
those entries were deallocated. That number can be viewed in the
pg_stat_statements_info view that this commit adds. It's useful when
tuning pg_stat_statements.max parameter. If it's high, i.e., the entries
are deallocated very frequently, which might cause the performance
regression and we can increase pg_stat_statements.max to avoid those
frequent deallocations.
The pg_stat_statements_info view is intended to display the statistics
of pg_stat_statements module itself. Currently it has only one column
"dealloc" indicating the number of times entries were deallocated.
But an upcoming patch will add other columns (for example, the time
at which pg_stat_statements statistics were last reset) into the view.
Author: Katsuragi Yuta, Yuki Seino
Reviewed-by: Fujii Masao
Discussion: https://postgr.es/m/0d9f1107772cf5c3f954e985464c7298@oss.nttdata.com
Commit 6023b7ea71 allowed pg_stat_statements to track the number
of rows retrieved or affected by some utility commands including
CREATE MATERIALIZED VIEW. However it did not track the rowcount
of REFRESH MATERIALIZED VIEW. This commit allows pg_stat_statements
to track that.
To track that, this commit changes the query completion for
REFRESH MATERIALIZED VIEW so that it saves the rowcount. But note that
the rowcount is still not displayed in the command completion tag output.
That is, the display_rowcount flag of CMDTAG_REFRESH_MATERIALIZED_VIEW
command tag is left false in cmdtaglist.h. Otherwise, the change of
completion tag output might break applications using it.
Author: Katsuragi Yuta, Seino Yuki
Reviewed-by: Fujii Masao
Discussion: https://postgr.es/m/71f6bc72f8bbaa06e701f8bd2562c347@oss.nttdata.com
Discussion: https://postgr.es/m/aadbfba9-e4bb-9531-6b3a-d13c31c8f4fe@oss.nttdata.com
This commit makes pg_stat_statements track the total number
of rows retrieved or affected by CREATE TABLE AS, SELECT INTO,
CREATE MATERIALIZED VIEW and FETCH commands.
Suggested-by: Pascal Legrand
Author: Fujii Masao
Reviewed-by: Asif Rehman
Discussion: https://postgr.es/m/1584293755198-0.post@n3.nabble.com
Since v13 pg_stat_statements is allowed to track the planning time of
statements when track_planning option is enabled. Its default was on.
But this feature could cause more terrible spinlock contentions in
pg_stat_statements. As a result of this, Robins Tharakan reported that
v13 beta1 showed ~45% performance drop at high DB connection counts
(when compared with v12.3) during fully-cached SELECT-only test using
pgbench.
To avoid this performance regression by the default setting,
this commit changes default of pg_stat_statements.track_planning to off.
Back-patch to v13 where pg_stat_statements.track_planning was introduced.
Reported-by: Robins Tharakan
Author: Fujii Masao
Reviewed-by: Julien Rouhaud
Discussion: https://postgr.es/m/2895b53b033c47ccb22972b589050dd9@EX13D05UWC001.ant.amazon.com
This commit adds three new columns in pg_stat_statements output to
display WAL usage statistics added by commit df3b181499.
This commit doesn't bump the version of pg_stat_statements as the
same is done for this release in commit 17e0328224.
Author: Kirill Bychik and Julien Rouhaud
Reviewed-by: Julien Rouhaud, Fujii Masao, Dilip Kumar and Amit Kapila
Discussion: https://postgr.es/m/CAB-hujrP8ZfUkvL5OYETipQwA=e3n7oqHFU=4ZLxWS_Cza3kQQ@mail.gmail.com
This commit makes pg_stat_statements support new GUC
pg_stat_statements.track_planning. If this option is enabled,
pg_stat_statements tracks the planning statistics of the statements,
e.g., the number of times the statement was planned, the total time
spent planning the statement, etc. This feature is useful to check
the statements that it takes a long time to plan. Previously since
pg_stat_statements tracked only the execution statistics, we could
not use that for the purpose.
The planning and execution statistics are stored at the end of
each phase separately. So there are not always one-to-one relationship
between them. For example, if the statement is successfully planned
but fails in the execution phase, only its planning statistics are stored.
This may cause the users to be able to see different pg_stat_statements
results from the previous version. To avoid this,
pg_stat_statements.track_planning needs to be disabled.
This commit bumps the version of pg_stat_statements to 1.8
since it changes the definition of pg_stat_statements function.
Author: Julien Rouhaud, Pascal Legrand, Thomas Munro, Fujii Masao
Reviewed-by: Sergei Kornilov, Tomas Vondra, Yoshikazu Imai, Haribabu Kommi, Tom Lane
Discussion: https://postgr.es/m/CAHGQGwFx_=DO-Gu-MfPW3VQ4qC7TfVdH2zHmvZfrGv6fQ3D-Tw@mail.gmail.com
Discussion: https://postgr.es/m/CAEepm=0e59Y_6Q_YXYCTHZkqOc6H2pJ54C_Xe=VFu50Aqqp_sA@mail.gmail.com
Discussion: https://postgr.es/m/DB6PR0301MB21352F6210E3B11934B0DCC790B00@DB6PR0301MB2135.eurprd03.prod.outlook.com
Performance of a SELECT FOR UPDATE may be quite distinct from the
non-UPDATE version of the query, so treat all of the FOR UPDATE clause
as being significant for distinguishing queries.
Andrew Gierth and Vik Fearing, reviewed by Sergei Kornilov, Thomas
Munro, Tom Lane
Discussion: https://postgr.es/m/87h8e4hfwv.fsf@news-spur.riddles.org.uk
particular user/db/query.
The function pg_stat_statements_reset() is extended to accept userid, dbid,
and queryid as input parameters. Now, it can discard the statistics
gathered so far by pg_stat_statements corresponding to the specified
userid, dbid, and queryid. If no parameter is specified or all the
specified parameters have default value aka 0, it will discard all
statistics as per the old behavior.
The new behavior is useful to get the fresh statistics for a specific
user/database/query without resetting all the existing statistics.
Author: Haribabu Kommi, with few additional changes by me
Reviewed-by: Michael Paquier, Amit Kapila and Fujii Masao
Discussion: https://postgr.es/m/CAJrrPGcyh-gkFswyc6C661K6cknL0XkNqVT0sQt2mFNMR4HRKA@mail.gmail.com
The trouble with the original choice here is that "?" is a valid (and
indeed used) operator name, so that you could end up with ambiguous
statement texts like "SELECT ? ? ?". With this patch, you instead
see "SELECT $1 ? $2", which seems significantly more readable.
The numbers used for this purpose begin after the last actual $N parameter
in the particular query. The conflict with external parameters has its own
potential for confusion of course, but it was agreed to be an improvement
over the previous behavior.
Lukas Fittl
Discussion: https://postgr.es/m/CAP53PkxeaCuwYmF-A4J5z2-qk5fYFo5_NH3gpXGJJBxv1DMwEw@mail.gmail.com
Make use of the statement boundary info added by commit ab1f0c822
to let pg_stat_statements behave more sanely when multiple SQL queries
are jammed into one query string. It now records just the relevant
part of the source string, not the whole thing, for each individual
query.
Even when no multi-statement strings are involved, users may notice small
changes in the output: leading and trailing whitespace and semicolons will
be stripped from statements, which did not happen before.
Also, significantly expand pg_stat_statements' regression test script.
Fabien Coelho, reviewed by Craig Ringer and Kyotaro Horiguchi,
some mods by me
Discussion: https://postgr.es/m/alpine.DEB.2.20.1612200926310.29821@lancre
While the set of covered functionality is fairly small, the added tests
still are useful to get some basic buildfarm testing of
pg_stat_statements itself, but also to exercise the lwlock tranch code
on the buildfarm.
Author: Amit Kapila, slightly editorialized by me
Reviewed-By: Ashutosh Sharma, Andres Freund
Discussion: <CAA4eK1JOjkdXYtHxh=2aDK4VgDtN-LNGKY_YqX0N=YEvuzQVWg@mail.gmail.com>
Peter Eisentraut
Alexander Korotkov
Michael Paquier
Tom Lane
Daniel Gustafsson
Andres Freund
Alvaro Herrera
Robert Haas
Magnus Hagander
Bruce Momjian
Fujii Masao
Amit Kapila
Andrew Gierth