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* Reorder superuser check in pg_log_backend_memory_contexts()Michael Paquier2021-06-08
| | | | | | | | | | | | | | | The use of this function is limited to superusers and the code includes a hardcoded check for that. However, the code would look for the PGPROC entry to signal for the memory dump before checking if the user is a superuser or not, which does not make sense if we know that an error will be returned. Note that the code would let one know if a process was a PostgreSQL process or not even for non-authorized users, which is not the case now, but this avoids taking ProcArrayLock that will most likely finish by being unnecessary. Thanks to Julien Rouhaud and Tom Lane for the discussion. Discussion: https://postgr.es/m/YLxw1uVGIAP5uMPl@paquier.xyz
* Adjust locations which have an incorrect copyright yearDavid Rowley2021-06-04
| | | | | | | A few patches committed after ca3b37487 mistakenly forgot to make the copyright year 2021. Fix these. Discussion: https://postgr.es/m/CAApHDvqyLmd9P2oBQYJ=DbrV8QwyPRdmXtCTFYPE08h+ip0UJw@mail.gmail.com
* Reject SELECT ... GROUP BY GROUPING SETS (()) FOR UPDATE.Tom Lane2021-06-01
| | | | | | | | | | | | | | | | | This case should be disallowed, just as FOR UPDATE with a plain GROUP BY is disallowed; FOR UPDATE only makes sense when each row of the query result can be identified with a single table row. However, we missed teaching CheckSelectLocking() to check groupingSets as well as groupClause, so that it would allow degenerate grouping sets. That resulted in a bad plan and a null-pointer dereference in the executor. Looking around for other instances of the same bug, the only one I found was in examine_simple_variable(). That'd just lead to silly estimates, but it should be fixed too. Per private report from Yaoguang Chen. Back-patch to all supported branches.
* Improve some error wording with multirange type parsingMichael Paquier2021-05-31
| | | | | | | | | | | | Braces were referred in some error messages as only brackets (not curly brackets or curly braces), which can be confusing as other types of brackets could be used. While on it, add one test to check after the case of junk characters detected after a right brace. Author: Kyotaro Horiguchi Discussion: https://postgr.es/m/20210514.153153.1814935914483287479.horikyota.ntt@gmail.com
* Initial pgindent and pgperltidy run for v14.Tom Lane2021-05-12
| | | | | | | | Also "make reformat-dat-files". The only change worthy of note is that pgindent messed up the formatting of launcher.c's struct LogicalRepWorkerId, which led me to notice that that struct wasn't used at all anymore, so I just took it out.
* Refactor some error messages for easier translationPeter Eisentraut2021-05-12
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* Prevent integer overflows in array subscripting calculations.Tom Lane2021-05-10
| | | | | | | | | | | | | | | | | | | | | | | | While we were (mostly) careful about ensuring that the dimensions of arrays aren't large enough to cause integer overflow, the lower bound values were generally not checked. This allows situations where lower_bound + dimension overflows an integer. It seems that that's harmless so far as array reading is concerned, except that array elements with subscripts notionally exceeding INT_MAX are inaccessible. However, it confuses various array-assignment logic, resulting in a potential for memory stomps. Fix by adding checks that array lower bounds aren't large enough to cause lower_bound + dimension to overflow. (Note: this results in disallowing cases where the last subscript position would be exactly INT_MAX. In principle we could probably allow that, but there's a lot of code that computes lower_bound + dimension and would need adjustment. It seems doubtful that it's worth the trouble/risk to allow it.) Somewhat independently of that, array_set_element() was careless about possible overflow when checking the subscript of a fixed-length array, creating a different route to memory stomps. Fix that too. Security: CVE-2021-32027
* Make pg_get_statisticsobjdef_expressions return NULLTomas Vondra2021-05-07
| | | | | | | | | The usual behavior for functions in ruleutils.c is to return NULL when the object does not exist. pg_get_statisticsobjdef_expressions raised an error instead, so correct that. Reported-by: Justin Pryzby Discussion: https://postgr.es/m/20210505210947.GA27406%40telsasoft.com
* Revert per-index collation version tracking feature.Thomas Munro2021-05-07
| | | | | | | | | | | | | | | | | | | | | | | Design problems were discovered in the handling of composite types and record types that would cause some relevant versions not to be recorded. Misgivings were also expressed about the use of the pg_depend catalog for this purpose. We're out of time for this release so we'll revert and try again. Commits reverted: 1bf946bd: Doc: Document known problem with Windows collation versions. cf002008: Remove no-longer-relevant test case. ef387bed: Fix bogus collation-version-recording logic. 0fb0a050: Hide internal error for pg_collation_actual_version(<bad OID>). ff942057: Suppress "warning: variable 'collcollate' set but not used". d50e3b1f: Fix assertion in collation version lookup. f24b1569: Rethink extraction of collation dependencies. 257836a7: Track collation versions for indexes. cd6f479e: Add pg_depend.refobjversion. 7d1297df: Remove pg_collation.collversion. Discussion: https://postgr.es/m/CA%2BhUKGLhj5t1fcjqAu8iD9B3ixJtsTNqyCCD4V0aTO9kAKAjjA%40mail.gmail.com
* Make websearch_to_tsquery() parse text in quotes as a single tokenAlexander Korotkov2021-05-03
| | | | | | | | | | | | | | | | | | | | | | | | websearch_to_tsquery() splits text in quotes into tokens and connects them with phrase operator on its own. However, that leads to surprising results when the token contains no words. For instance, websearch_to_tsquery('"aaa: bbb"') is 'aaa <2> bbb', because it is equivalent of to_tsquery(E'aaa <-> \':\' <-> bbb'). But websearch_to_tsquery('"aaa: bbb"') has to be 'aaa <-> bbb' in order to match to_tsvector('aaa: bbb'). Since 0c4f355c6a, we anyway connect lexemes of complex tokens with phrase operators. Thus, let's just websearch_to_tsquery() parse text in quotes as a single token. Therefore, websearch_to_tsquery() should process the quoted text in the same way phraseto_tsquery() does. This solution is what we exactly need and also simplifies the code. This commit is an incompatible change, so we don't backpatch it. Reported-by: Valentin Gatien-Baron Discussion: https://postgr.es/m/CA%2B0DEqiZs7gdOd4ikmg%3D0UWG%2BSwWOLxPsk_JW-sx9WNOyrb0KQ%40mail.gmail.com Author: Alexander Korotkov Reviewed-by: Tom Lane, Zhihong Yu
* Revert use singular for -1 (commits 9ee7d533da and 5da9868ed9Bruce Momjian2021-05-01
| | | | | | | | | | | | | | Turns out you can specify negative values using plurals: https://english.stackexchange.com/questions/9735/is-1-followed-by-a-singular-or-plural-noun so the previous code was correct enough, and consistent with other usage in our code. Also add comment in the two places where this could be confused. Reported-by: Noah Misch Diagnosed-by: 20210425115726.GA2353095@rfd.leadboat.com
* Use HTAB for replication slot statistics.Amit Kapila2021-04-27
| | | | | | | | | | | | | | | | | | | | | | | 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
* Mark multirange_constructor0() and multirange_constructor2() strictAlexander Korotkov2021-04-23
| | | | | | | | | | | | | | | | These functions shouldn't receive null arguments: multirange_constructor0() doesn't have any arguments while multirange_constructor2() has a single array argument, which is never null. But mark them strict anyway for the sake of uniformity. Also, make checks for null arguments use elog() instead of ereport() as these errors should normally be never thrown. And adjust corresponding comments. Catversion is bumped. Reported-by: Peter Eisentraut Discussion: https://postgr.es/m/0f783a96-8d67-9e71-996b-f34a7352eeef%40enterprisedb.com
* adjust query id feature to use pg_stat_activity.query_idBruce Momjian2021-04-20
| | | | | | | | | | | 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
* Fix typos and grammar in comments and docsMichael Paquier2021-04-19
| | | | | Author: Justin Pryzby Discussion: https://postgr.es/m/20210416070310.GG3315@telsasoft.com
* Add information of total data processed to replication slot stats.Amit Kapila2021-04-16
| | | | | | | | | | | | 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
* Use NameData datatype for slotname in stats.Amit Kapila2021-04-14
| | | | | | | | | | | This will make it consistent with the other usage of slotname in the code. In the passing, change pgstat_report_replslot signature to use a structure rather than multiple parameters. Reported-by: Andres Freund Author: Vignesh C Reviewed-by: Sawada Masahiko, Amit Kapila Discussion: https://postgr.es/m/20210319185247.ldebgpdaxsowiflw@alap3.anarazel.de
* Use "-I." in directories holding Bison parsers, for Oracle compilers.Noah Misch2021-04-12
| | | | | | | | | With the Oracle Developer Studio 12.6 compiler, #line directives alter the current source file location for purposes of #include "..." directives. Hence, a VPATH build failed with 'cannot find include file: "specscanner.c"'. With two exceptions, parser-containing directories already add "-I. -I$(srcdir)"; eliminate the exceptions. Back-patch to 9.6 (all supported versions).
* Fix out-of-bound memory access for interval -> char conversionMichael Paquier2021-04-12
| | | | | | | | | | | | | | | | | | | | Using Roman numbers (via "RM" or "rm") for a conversion to calculate a number of months has never considered the case of negative numbers, where a conversion could easily cause out-of-bound memory accesses. The conversions in themselves were not completely consistent either, as specifying 12 would result in NULL, but it should mean XII. This commit reworks the conversion calculation to have a more consistent behavior: - If the number of months and years is 0, return NULL. - If the number of months is positive, return the exact month number. - If the number of months is negative, do a backward calculation, with -1 meaning December, -2 November, etc. Reported-by: Theodor Arsenij Larionov-Trichkin Author: Julien Rouhaud Discussion: https://postgr.es/m/16953-f255a18f8c51f1d5@postgresql.org backpatch-through: 9.6
* Silence some Coverity warnings and improve code consistency.Tom Lane2021-04-11
| | | | | | | | | | | | | | | | Coverity complained about possible overflow in expressions like intresult = tm->tm_sec * 1000000 + fsec; on the grounds that the multiplication would happen in 32-bit arithmetic before widening to the int64 result. I think these are all false positives because of the limited possible range of tm_sec; but nonetheless it seems silly to spell it like that when nearby lines have the identical computation written with a 64-bit constant. ... or more accurately, with an LL constant, which is not project style. Make all of these use INT64CONST(), as we do elsewhere. This is all new code from a2da77cdb, so no need for back-patch.
* Standardize pg_authid oid_symbol values.Noah Misch2021-04-10
| | | | | | Commit c9c41c7a337d3e2deb0b2a193e9ecfb865d8f52b used two different naming patterns. Standardize on the majority pattern, which was the only pattern in the last reviewed version of that commit.
* Improve behavior of date_bin with origin in the futurePeter Eisentraut2021-04-10
| | | | | | | | | | Currently, when the origin is after the input, the result is the timestamp at the end of the bin, rather than the beginning as expected. This puts the result consistently at the beginning of the bin. Author: John Naylor <john.naylor@enterprisedb.com> Discussion: https://www.postgresql.org/message-id/CAFBsxsGjLDxQofRfH+d4KSAXxPf3MMevUG7s6EDfdBOvHLDLjw@mail.gmail.com
* Fix typos and grammar in documentation and code commentsMichael Paquier2021-04-09
| | | | | | | | | Comment fixes are applied on HEAD, and documentation improvements are applied on back-branches where needed. Author: Justin Pryzby Discussion: https://postgr.es/m/20210408164008.GJ6592@telsasoft.com Backpatch-through: 9.6
* Fixes for query_id featureBruce Momjian2021-04-08
| | | | | | | | | | | | | | | | | | Ignore parallel workers in pg_stat_statements Oversight in 4f0b0966c8 which exposed queryid in parallel workers. Counters are aggregated by the main backend process so parallel workers would report duplicated activity, and could also report activity for the wrong entry as they are only aware of the top level queryid. Fix thinko in pg_stat_get_activity when retrieving the queryid. Remove unnecessary call to pgstat_report_queryid(). Reported-by: Amit Kapila, Andres Freund, Thomas Munro Discussion: https://postgr.es/m/20210408051735.lfbdzun5zdlax5gd@alap3.anarazel.de p634GTSOqnDW86Owrn6qDAVosC5dJjXjp7BMfc5Gz1Q@mail.gmail.com Author: Julien Rouhaud
* Fix typo in jsonfuncs.c.Amit Kapila2021-04-08
| | | | | Author: Tatsuro Yamada Discussion: https://postgr.es/m/7c166a60-2808-6b89-9524-feefc6233748@nttcom.co.jp_1
* SQL-standard function bodyPeter Eisentraut2021-04-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This adds support for writing CREATE FUNCTION and CREATE PROCEDURE statements for language SQL with a function body that conforms to the SQL standard and is portable to other implementations. Instead of the PostgreSQL-specific AS $$ string literal $$ syntax, this allows writing out the SQL statements making up the body unquoted, either as a single statement: CREATE FUNCTION add(a integer, b integer) RETURNS integer LANGUAGE SQL RETURN a + b; or as a block CREATE PROCEDURE insert_data(a integer, b integer) LANGUAGE SQL BEGIN ATOMIC INSERT INTO tbl VALUES (a); INSERT INTO tbl VALUES (b); END; The function body is parsed at function definition time and stored as expression nodes in a new pg_proc column prosqlbody. So at run time, no further parsing is required. However, this form does not support polymorphic arguments, because there is no more parse analysis done at call time. Dependencies between the function and the objects it uses are fully tracked. A new RETURN statement is introduced. This can only be used inside function bodies. Internally, it is treated much like a SELECT statement. psql needs some new intelligence to keep track of function body boundaries so that it doesn't send off statements when it sees semicolons that are inside a function body. Tested-by: Jaime Casanova <jcasanov@systemguards.com.ec> Reviewed-by: Julien Rouhaud <rjuju123@gmail.com> Discussion: https://www.postgresql.org/message-id/flat/1c11f1eb-f00c-43b7-799d-2d44132c02d7@2ndquadrant.com
* Make use of in-core query id added by commit 5fd9dfa5f5Bruce Momjian2021-04-07
| | | | | | | | | | | | | | | | | | | | | | | 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
* Change return type of EXTRACT to numericPeter Eisentraut2021-04-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The previous implementation of EXTRACT mapped internally to date_part(), which returned type double precision (since it was implemented long before the numeric type existed). This can lead to imprecise output in some cases, so returning numeric would be preferrable. Changing the return type of an existing function is a bit risky, so instead we do the following: We implement a new set of functions, which are now called "extract", in parallel to the existing date_part functions. They work the same way internally but use numeric instead of float8. The EXTRACT construct is now mapped by the parser to these new extract functions. That way, dumps of views etc. from old versions (which would use date_part) continue to work unchanged, but new uses will map to the new extract functions. Additionally, the reverse compilation of EXTRACT now reproduces the original syntax, using the new mechanism introduced in 40c24bfef92530bd846e111c1742c2a54441c62c. The following minor changes of behavior result from the new implementation: - The column name from an isolated EXTRACT call is now "extract" instead of "date_part". - Extract from date now rejects inappropriate field names such as HOUR. It was previously mapped internally to extract from timestamp, so it would silently accept everything appropriate for timestamp. - Return values when extracting fields with possibly fractional values, such as second and epoch, now have the full scale that the value has internally (so, for example, '1.000000' instead of just '1'). Reported-by: Petr Fedorov <petr.fedorov@phystech.edu> Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us> Discussion: https://www.postgresql.org/message-id/flat/42b73d2d-da12-ba9f-570a-420e0cce19d9@phystech.edu
* Add function to log the memory contexts of specified backend process.Fujii Masao2021-04-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 3e98c0bafb added pg_backend_memory_contexts view to display the memory contexts of the backend process. However its target process is limited to the backend that is accessing to the view. So this is not so convenient when investigating the local memory bloat of other backend process. To improve this situation, this commit adds pg_log_backend_memory_contexts() function that requests to log the memory contexts of the specified backend process. This information can be also collected by calling MemoryContextStats(TopMemoryContext) via a debugger. But this technique cannot be used in some environments because no debugger is available there. So, pg_log_backend_memory_contexts() allows us to see the memory contexts of specified backend more easily. Only superusers are allowed to request to log the memory contexts because allowing any users to issue this request at an unbounded rate would cause lots of log messages and which can lead to denial of service. On receipt of the request, at the next CHECK_FOR_INTERRUPTS(), the target backend logs its memory contexts at LOG_SERVER_ONLY level, so that these memory contexts will appear in the server log but not be sent to the client. It logs one message per memory context. Because if it buffers all memory contexts into StringInfo to log them as one message, which may require the buffer to be enlarged very much and lead to OOM error since there can be a large number of memory contexts in a backend. When a backend process is consuming huge memory, logging all its memory contexts might overrun available disk space. To prevent this, now this patch limits the number of child contexts to log per parent to 100. As with MemoryContextStats(), it supposes that practical cases where the log gets long will typically be huge numbers of siblings under the same parent context; while the additional debugging value from seeing details about individual siblings beyond 100 will not be large. There was another proposed patch to add the function to return the memory contexts of specified backend as the result sets, instead of logging them, in the discussion. However that patch is not included in this commit because it had several issues to address. Thanks to Tatsuhito Kasahara, Andres Freund, Tom Lane, Tomas Vondra, Michael Paquier, Kyotaro Horiguchi and Zhihong Yu for the discussion. Bump catalog version. Author: Atsushi Torikoshi Reviewed-by: Kyotaro Horiguchi, Zhihong Yu, Fujii Masao Discussion: https://postgr.es/m/0271f440ac77f2a4180e0e56ebd944d1@oss.nttdata.com
* Fix more confusion in SP-GiST.Tom Lane2021-04-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | spg_box_quad_leaf_consistent unconditionally returned the leaf datum as leafValue, even though in its usage for poly_ops that value is of completely the wrong type. In versions before 12, that was harmless because the core code did nothing with leafValue in non-index-only scans ... but since commit 2a6368343, if we were doing a KNN-style scan, spgNewHeapItem would unconditionally try to copy the value using the wrong datatype parameters. Said copying is a waste of time and space if we're not going to return the data, but it accidentally failed to fail until I fixed the datatype confusion in ac9099fc1. Hence, change spgNewHeapItem to not copy the datum unless we're actually going to return it later. This saves cycles and dodges the question of whether lossy opclasses are returning the right type. Also change spg_box_quad_leaf_consistent to not return data that might be of the wrong type, as insurance against somebody introducing a similar bug into the core code in future. It seems like a good idea to back-patch these two changes into v12 and v13, although I'm afraid to change spgNewHeapItem's mistaken idea of which datatype to use in those branches. Per buildfarm results from ac9099fc1. Discussion: https://postgr.es/m/3728741.1617381471@sss.pgh.pa.us
* Do not rely on pgstat.h to indirectly include storage/ headers.Andres Freund2021-04-02
| | | | | | | | An upcoming patch might remove the (now indirect) proc.h include (which in turn includes other headers), and it's cleaner for the modified files to include their dependencies directly anyway... Discussion: https://postgr.es/m/20210402194458.2vu324hkk2djq6ce@alap3.anarazel.de
* Rename Default Roles to Predefined RolesStephen Frost2021-04-01
| | | | | | | | | | | | | The term 'default roles' wasn't quite apt as these roles aren't able to be modified or removed after installation, so rename them to be 'Predefined Roles' instead, adding an entry into the newly added Obsolete Appendix to help users of current releases find the new documentation. Bruce Momjian and Stephen Frost Discussion: https://postgr.es/m/157742545062.1149.11052653770497832538%40wrigleys.postgresql.org and https://www.postgresql.org/message-id/20201120211304.GG16415@tamriel.snowman.net
* Fix internal extract(timezone_minute) formulasPeter Eisentraut2021-04-01
| | | | | | | | | | Through various refactorings over time, the extract(timezone_minute from time with time zone) and extract(timezone_minute from timestamp with time zone) implementations ended up with two different but equally nonsensical formulas by using SECS_PER_MINUTE and MINS_PER_HOUR interchangeably. Since those two are of course both the same number, the formulas do work, but for readability, fix them to be semantically correct.
* Fix has_column_privilege function corner caseJoe Conway2021-03-31
| | | | | | | | | | | | | | | | | | | | | | | According to the comments, when an invalid or dropped column oid is passed to has_column_privilege(), the intention has always been to return NULL. However, when the caller had table level privilege the invalid/missing column was never discovered, because table permissions were checked first. Fix that by introducing extended versions of pg_attribute_acl(check|mask) and pg_class_acl(check|mask) which take a new argument, is_missing. When is_missing is NULL, the old behavior is preserved. But when is_missing is passed by the caller, no ERROR is thrown for dropped or missing columns/relations, and is_missing is flipped to true. This in turn allows has_column_privilege to check for column privileges first, providing the desired semantics. Not backpatched since it is a user visible behavioral change with no previous complaints, and the fix is a bit on the invasive side. Author: Joe Conway Reviewed-By: Tom Lane Reported by: Ian Barwick Discussion: https://postgr.es/m/flat/9b5f4311-157b-4164-7fe7-077b4fe8ed84%40joeconway.com
* Rework planning and execution of UPDATE and DELETE.Tom Lane2021-03-31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch makes two closely related sets of changes: 1. For UPDATE, the subplan of the ModifyTable node now only delivers the new values of the changed columns (i.e., the expressions computed in the query's SET clause) plus row identity information such as CTID. ModifyTable must re-fetch the original tuple to merge in the old values of any unchanged columns. The core advantage of this is that the changed columns are uniform across all tables of an inherited or partitioned target relation, whereas the other columns might not be. A secondary advantage, when the UPDATE involves joins, is that less data needs to pass through the plan tree. The disadvantage of course is an extra fetch of each tuple to be updated. However, that seems to be very nearly free in context; even worst-case tests don't show it to add more than a couple percent to the total query cost. At some point it might be interesting to combine the re-fetch with the tuple access that ModifyTable must do anyway to mark the old tuple dead; but that would require a good deal of refactoring and it seems it wouldn't buy all that much, so this patch doesn't attempt it. 2. For inherited UPDATE/DELETE, instead of generating a separate subplan for each target relation, we now generate a single subplan that is just exactly like a SELECT's plan, then stick ModifyTable on top of that. To let ModifyTable know which target relation a given incoming row refers to, a tableoid junk column is added to the row identity information. This gets rid of the horrid hack that was inheritance_planner(), eliminating O(N^2) planning cost and memory consumption in cases where there were many unprunable target relations. Point 2 of course requires point 1, so that there is a uniform definition of the non-junk columns to be returned by the subplan. We can't insist on uniform definition of the row identity junk columns however, if we want to keep the ability to have both plain and foreign tables in a partitioning hierarchy. Since it wouldn't scale very far to have every child table have its own row identity column, this patch includes provisions to merge similar row identity columns into one column of the subplan result. In particular, we can merge the whole-row Vars typically used as row identity by FDWs into one column by pretending they are type RECORD. (It's still okay for the actual composite Datums to be labeled with the table's rowtype OID, though.) There is more that can be done to file down residual inefficiencies in this patch, but it seems to be committable now. FDW authors should note several API changes: * The argument list for AddForeignUpdateTargets() has changed, and so has the method it must use for adding junk columns to the query. Call add_row_identity_var() instead of manipulating the parse tree directly. You might want to reconsider exactly what you're adding, too. * PlanDirectModify() must now work a little harder to find the ForeignScan plan node; if the foreign table is part of a partitioning hierarchy then the ForeignScan might not be the direct child of ModifyTable. See postgres_fdw for sample code. * To check whether a relation is a target relation, it's no longer sufficient to compare its relid to root->parse->resultRelation. Instead, check it against all_result_relids or leaf_result_relids, as appropriate. Amit Langote and Tom Lane Discussion: https://postgr.es/m/CA+HiwqHpHdqdDn48yCEhynnniahH78rwcrv1rEX65-fsZGBOLQ@mail.gmail.com
* Allow an alias to be attached to a JOIN ... USINGPeter Eisentraut2021-03-31
| | | | | | | | | | | | | | | This allows something like SELECT ... FROM t1 JOIN t2 USING (a, b, c) AS x where x has the columns a, b, c and unlike a regular alias it does not hide the range variables of the tables being joined t1 and t2. Per SQL:2016 feature F404 "Range variable for common column names". Reviewed-by: Vik Fearing <vik.fearing@2ndquadrant.com> Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us> Discussion: https://www.postgresql.org/message-id/flat/454638cf-d563-ab76-a585-2564428062af@2ndquadrant.com
* In messages, use singular nouns for -1, like we do for +1.Bruce Momjian2021-03-30
| | | | | | | | | | This outputs "-1 year", not "-1 years". Reported-by: neverov.max@gmail.com Bug: 16939 Discussion: https://postgr.es/m/16939-cceeb03fb72736ee@postgresql.org
* Allow estimate_num_groups() to pass back further details about the estimationDavid Rowley2021-03-30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Here we add a new output parameter to estimate_num_groups() to allow it to inform the caller of additional, possibly useful information about the estimation. The new output parameter is a struct that currently contains just a single field with a set of flags. This was done rather than having the flags as an output parameter to allow future fields to be added without having to change the signature of the function at a later date when we want to pass back further information that might not be suitable to store in the flags field. It seems reasonable that one day in the future that the planner would want to know more about the estimation. For example, how many individual sets of statistics was the estimation generated from? The planner may want to take that into account if we ever want to consider risks as well as costs when generating plans. For now, there's only 1 flag we set in the flags field. This is to indicate if the estimation fell back on using the hard-coded constants in any part of the estimation. Callers may like to change their behavior if this is set, and this gives them the ability to do so. Callers may pass the flag pointer as NULL if they have no interest in obtaining any additional information about the estimate. We're not adding any actual usages of these flags here. Some follow-up commits will make use of this feature. Additionally, we're also not making any changes to add support for clauselist_selectivity() and clauselist_selectivity_ext(). However, if this is required in the future then the same struct being added here should be fine to use as a new output argument for those functions too. Author: David Rowley Discussion: https://postgr.es/m/CAApHDvqQqpk=1W-G_ds7A9CsXX3BggWj_7okinzkLVhDubQzjA@mail.gmail.com
* Fix compiler warning in unistr functionDavid Rowley2021-03-30
| | | | Some compilers are not aware that elog/ereport ERROR does not return.
* Add unistr functionPeter Eisentraut2021-03-29
| | | | | | | | | This allows decoding a string with Unicode escape sequences. It is similar to Unicode escape strings, but offers some more flexibility. Author: Pavel Stehule <pavel.stehule@gmail.com> Reviewed-by: Asif Rehman <asifr.rehman@gmail.com> Discussion: https://www.postgresql.org/message-id/flat/CAFj8pRA5GnKT+gDVwbVRH2ep451H_myBt+NTz8RkYUARE9+qOQ@mail.gmail.com
* Extended statistics on expressionsTomas Vondra2021-03-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
* Fix ndistinct estimates with system attributesTomas Vondra2021-03-26
| | | | | | | | | | | | | | | | | | | | When estimating the number of groups using extended statistics, the code was discarding information about system attributes. This led to strange situation that SELECT 1 FROM t GROUP BY ctid; could have produced higher estimate (equal to pg_class.reltuples) than SELECT 1 FROM t GROUP BY a, b, ctid; with extended statistics on (a,b). Fixed by retaining information about the system attribute. Backpatch all the way to 10, where extended statistics were introduced. Author: Tomas Vondra Backpatch-through: 10
* Add "pg_database_owner" default role.Noah Misch2021-03-26
| | | | | | | | | | | Membership consists, implicitly, of the current database owner. Expect use in template databases. Once pg_database_owner has rights within a template, each owner of a database instantiated from that template will exercise those rights. Reviewed by John Naylor. Discussion: https://postgr.es/m/20201228043148.GA1053024@rfd.leadboat.com
* Merge similar algorithms into roles_is_member_of().Noah Misch2021-03-26
| | | | | | | | | The next commit would have complicated two or three algorithms, so take this opportunity to consolidate. No functional changes. Reviewed by John Naylor. Discussion: https://postgr.es/m/20201228043148.GA1053024@rfd.leadboat.com
* ALTER TABLE ... DETACH PARTITION ... CONCURRENTLYAlvaro Herrera2021-03-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Allow a partition be detached from its partitioned table without blocking concurrent queries, by running in two transactions and only requiring ShareUpdateExclusive in the partitioned table. Because it runs in two transactions, it cannot be used in a transaction block. This is the main reason to use dedicated syntax: so that users can choose to use the original mode if they need it. But also, it doesn't work when a default partition exists (because an exclusive lock would still need to be obtained on it, in order to change its partition constraint.) In case the second transaction is cancelled or a crash occurs, there's ALTER TABLE .. DETACH PARTITION .. FINALIZE, which executes the final steps. The main trick to make this work is the addition of column pg_inherits.inhdetachpending, initially false; can only be set true in the first part of this command. Once that is committed, concurrent transactions that use a PartitionDirectory will include or ignore partitions so marked: in optimizer they are ignored if the row is marked committed for the snapshot; in executor they are always included. As a result, and because of the way PartitionDirectory caches partition descriptors, queries that were planned before the detach will see the rows in the detached partition and queries that are planned after the detach, won't. A CHECK constraint is created that duplicates the partition constraint. This is probably not strictly necessary, and some users will prefer to remove it afterwards, but if the partition is re-attached to a partitioned table, the constraint needn't be rechecked. Author: Álvaro Herrera <alvherre@alvh.no-ip.org> Reviewed-by: Amit Langote <amitlangote09@gmail.com> Reviewed-by: Justin Pryzby <pryzby@telsasoft.com> Discussion: https://postgr.es/m/20200803234854.GA24158@alvherre.pgsql
* Fix stray double semicolonsPeter Eisentraut2021-03-24
| | | | Reported-by: John Naylor <john.naylor@enterprisedb.com>
* Add date_bin functionPeter Eisentraut2021-03-24
| | | | | | | | | | | | Similar to date_trunc, but allows binning by an arbitrary interval rather than just full units. Author: John Naylor <john.naylor@enterprisedb.com> Reviewed-by: David Fetter <david@fetter.org> Reviewed-by: Isaac Morland <isaac.morland@gmail.com> Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us> Reviewed-by: Artur Zakirov <zaartur@gmail.com> Discussion: https://www.postgresql.org/message-id/flat/CACPNZCt4buQFRgy6DyjuZS-2aPDpccRkrJBmgUfwYc1KiaXYxg@mail.gmail.com
* Add bit_count SQL functionPeter Eisentraut2021-03-23
| | | | | | | | | | | This function for bit and bytea counts the set bits in the bit or byte string. Internally, we use the existing popcount functionality. For the name, after some discussion, we settled on bit_count, which also exists with this meaning in MySQL, Java, and Python. Author: David Fetter <david@fetter.org> Discussion: https://www.postgresql.org/message-id/flat/20201230105535.GJ13234@fetter.org
* Allow configurable LZ4 TOAST compression.Robert Haas2021-03-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is now a per-column COMPRESSION option which can be set to pglz (the default, and the only option in up until now) or lz4. Or, if you like, you can set the new default_toast_compression GUC to lz4, and then that will be the default for new table columns for which no value is specified. We don't have lz4 support in the PostgreSQL code, so to use lz4 compression, PostgreSQL must be built --with-lz4. In general, TOAST compression means compression of individual column values, not the whole tuple, and those values can either be compressed inline within the tuple or compressed and then stored externally in the TOAST table, so those properties also apply to this feature. Prior to this commit, a TOAST pointer has two unused bits as part of the va_extsize field, and a compessed datum has two unused bits as part of the va_rawsize field. These bits are unused because the length of a varlena is limited to 1GB; we now use them to indicate the compression type that was used. This means we only have bit space for 2 more built-in compresison types, but we could work around that problem, if necessary, by introducing a new vartag_external value for any further types we end up wanting to add. Hopefully, it won't be too important to offer a wide selection of algorithms here, since each one we add not only takes more coding but also adds a build dependency for every packager. Nevertheless, it seems worth doing at least this much, because LZ4 gets better compression than PGLZ with less CPU usage. It's possible for LZ4-compressed datums to leak into composite type values stored on disk, just as it is for PGLZ. It's also possible for LZ4-compressed attributes to be copied into a different table via SQL commands such as CREATE TABLE AS or INSERT .. SELECT. It would be expensive to force such values to be decompressed, so PostgreSQL has never done so. For the same reasons, we also don't force recompression of already-compressed values even if the target table prefers a different compression method than was used for the source data. These architectural decisions are perhaps arguable but revisiting them is well beyond the scope of what seemed possible to do as part of this project. However, it's relatively cheap to recompress as part of VACUUM FULL or CLUSTER, so this commit adjusts those commands to do so, if the configured compression method of the table happens not to match what was used for some column value stored therein. Dilip Kumar. The original patches on which this work was based were written by Ildus Kurbangaliev, and those were patches were based on even earlier work by Nikita Glukhov, but the design has since changed very substantially, since allow a potentially large number of compression methods that could be added and dropped on a running system proved too problematic given some of the architectural issues mentioned above; the choice of which specific compression method to add first is now different; and a lot of the code has been heavily refactored. More recently, Justin Przyby helped quite a bit with testing and reviewing and this version also includes some code contributions from him. Other design input and review from Tomas Vondra, Álvaro Herrera, Andres Freund, Oleg Bartunov, Alexander Korotkov, and me. Discussion: http://postgr.es/m/20170907194236.4cefce96%40wp.localdomain Discussion: http://postgr.es/m/CAFiTN-uUpX3ck%3DK0mLEk-G_kUQY%3DSNOTeqdaNRR9FMdQrHKebw%40mail.gmail.com
* Implement GROUP BY DISTINCTTomas Vondra2021-03-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With grouping sets, it's possible that some of the grouping sets are duplicate. This is especially common with CUBE and ROLLUP clauses. For example GROUP BY CUBE (a,b), CUBE (b,c) is equivalent to GROUP BY GROUPING SETS ( (a, b, c), (a, b, c), (a, b, c), (a, b), (a, b), (a, b), (a), (a), (a), (c, a), (c, a), (c, a), (c), (b, c), (b), () ) Some of the grouping sets are calculated multiple times, which is mostly unnecessary. This commit implements a new GROUP BY DISTINCT feature, as defined in the SQL standard, which eliminates the duplicate sets. Author: Vik Fearing Reviewed-by: Erik Rijkers, Georgios Kokolatos, Tomas Vondra Discussion: https://postgr.es/m/bf3805a8-d7d1-ae61-fece-761b7ff41ecc@postgresfriends.org