32 Commits (179c4639cf1dcbe54f3469d7f44a11f172332893)

Author	SHA1	Message	Date
Michael Paquier	179c4639cf	pg_stat_statements: Remove duplicated tests for SET statements ... This looks like a copy-paste mistake introduced in de2aca2885, that has added checks for more patterns of SET statements while ignoring the original test block that existed. Backpatch down to where this has been introduced, as this shaves some cycles. Author: Sergei Kornilov Discussion: https://postgr.es/m/5689421699428803@mail-sendbernar-production-main-46.myt.yp-c.yandex.net Backpatch-through: 16	2 years ago
Andres Freund	c4758649b4	Fix tracking of temp table relation extensions as writes ... 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	2 years ago
Michael Paquier	daa8365a90	Reflect normalization of query strings for utilities in pg_stat_statements ... 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	3 years ago
Michael Paquier	9a714b9d6e	Improve cleanup phases in regression tests of pg_stat_statements ... 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	3 years ago
Michael Paquier	d0028e35a0	Refactor more the regression tests of pg_stat_statements ... 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	3 years ago
Michael Paquier	de2aca2885	Expand regression tests of pg_stat_statements for utility queries ... 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	3 years ago
Michael Paquier	e8dbdb15db	Refactor tests of pg_stat_statements for planning, utility and level tracking ... 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	3 years ago
Michael Paquier	9ba37b2cb6	Include values of A_Const nodes in query jumbling ... 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	3 years ago
Michael Paquier	3db72ebcbe	Generate code for query jumbling through gen_node_support.pl ... 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	3 years ago
Alvaro Herrera	249b0409b1	Fix pg_stat_statements for MERGE ... 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	3 years ago
Robert Haas	2d7ead8526	pg_stat_statements: Fix test that assumes wal_records = rows. ... 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	3 years ago
Magnus Hagander	57d6aea00f	Add JIT counters to pg_stat_statements ... This adds cumulative counters for jit operations to pg_stat_statements, making it easier to diagnose how JIT is used in an installation. These changes merge into the 1.10 changes applied in 76cbf7edb6 without creating a new version. Reviewed-By: Julien Rouhaud Discussion: https://www.postgresql.org/message-id/flat/CABUevEySt4NTYqvWzwyAW_0-jG1bjN-y+tykapAnA0FALOs+Lw@mail.gmail.com	3 years ago
Michael Paquier	76cbf7edb6	pg_stat_statements: Track I/O timing for temporary file blocks ... 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	3 years ago
Peter Eisentraut	7844c9918a	psql: Show all query results by default ... 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	3 years ago
Tom Lane	83884682f4	psql: include intra-query "--" comments in what's sent to the server. ... 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	4 years ago
Michael Paquier	2b0da0365b	pg_stat_statements: Add some tests for older versions still usable ... 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	4 years ago
Tom Lane	0806d08d46	Harden pg_stat_statements tests against CLOBBER_CACHE_ALWAYS. ... Turns out the buildfarm hasn't been testing this, which will soon change. Julien Rouhaud, per report from me Discussion: https://postgr.es/m/42557.1627229005@sss.pgh.pa.us	4 years ago
Bruce Momjian	f7a97b6ec3	Update query_id computation ... 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	4 years ago
Peter Eisentraut	fae65629ce	Revert "psql: Show all query results by default" ... This reverts commit 3a51306722. Per discussion, this patch had too many issues to resolve at this point of the development cycle. We'll try again in the future. Discussion: https://www.postgresql.org/message-id/flat/alpine.DEB.2.21.1904132231510.8961@lancre	4 years ago
Magnus Hagander	6b4d23feef	Track identical top vs nested queries independently in pg_stat_statements ... 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	4 years ago
Peter Eisentraut	3a51306722	psql: Show all query results by default ... 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	4 years ago
Fujii Masao	9fbc3f318d	pg_stat_statements: Track number of times pgss entries were deallocated. ... 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	5 years ago
Fujii Masao	b62e6056a0	pg_stat_statements: track number of rows processed by REFRESH MATERIALIZED VIEW. ... 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	5 years ago
Fujii Masao	6023b7ea71	pg_stat_statements: track number of rows processed by some utility commands. ... 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	5 years ago
Fujii Masao	d1763ea8c9	Change default of pg_stat_statements.track_planning to off. ... 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	5 years ago
Amit Kapila	6b466bf5f2	Allow pg_stat_statements to track WAL usage statistics. ... 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	6 years ago
Fujii Masao	17e0328224	Allow pg_stat_statements to track planning statistics. ... 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	6 years ago
Andrew Gierth	6e74c64bcf	Teach pg_stat_statements not to ignore FOR UPDATE clauses ... 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	6 years ago
Amit Kapila	43cbedab8f	Extend pg_stat_statements_reset to reset statistics specific to a ... 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	7 years ago
Tom Lane	a6f22e8356	Show ignored constants as "$N" rather than "?" in pg_stat_statements. ... 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	9 years ago
Tom Lane	83f2061dd0	Teach contrib/pg_stat_statements to handle multi-statement commands better. ... 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	9 years ago
Andres Freund	9be244dbe8	Add minimal set of regression tests for pg_stat_statements. ... 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>	9 years ago