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2021-04-01Rename Default Roles to Predefined RolesStephen Frost
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
2021-04-01Fix internal extract(timezone_minute) formulasPeter Eisentraut
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.
2021-03-31Fix has_column_privilege function corner caseJoe Conway
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
2021-03-31Rework planning and execution of UPDATE and DELETE.Tom Lane
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
2021-03-31Allow an alias to be attached to a JOIN ... USINGPeter Eisentraut
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
2021-03-30In messages, use singular nouns for -1, like we do for +1.Bruce Momjian
This outputs "-1 year", not "-1 years". Reported-by: neverov.max@gmail.com Bug: 16939 Discussion: https://postgr.es/m/16939-cceeb03fb72736ee@postgresql.org
2021-03-30Allow estimate_num_groups() to pass back further details about the estimationDavid Rowley
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
2021-03-30Fix compiler warning in unistr functionDavid Rowley
Some compilers are not aware that elog/ereport ERROR does not return.
2021-03-29Add unistr functionPeter Eisentraut
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
2021-03-27Extended statistics on expressionsTomas Vondra
Allow defining extended statistics on expressions, not just just on simple column references. With this commit, expressions are supported by all existing extended statistics kinds, improving the same types of estimates. A simple example may look like this: CREATE TABLE t (a int); CREATE STATISTICS s ON mod(a,10), mod(a,20) FROM t; ANALYZE t; The collected statistics are useful e.g. to estimate queries with those expressions in WHERE or GROUP BY clauses: SELECT * FROM t WHERE mod(a,10) = 0 AND mod(a,20) = 0; SELECT 1 FROM t GROUP BY mod(a,10), mod(a,20); This introduces new internal statistics kind 'e' (expressions) which is built automatically when the statistics object definition includes any expressions. This represents single-expression statistics, as if there was an expression index (but without the index maintenance overhead). The statistics is stored in pg_statistics_ext_data as an array of composite types, which is possible thanks to 79f6a942bd. CREATE STATISTICS allows building statistics on a single expression, in which case in which case it's not possible to specify statistics kinds. A new system view pg_stats_ext_exprs can be used to display expression statistics, similarly to pg_stats and pg_stats_ext views. ALTER TABLE ... ALTER COLUMN ... TYPE now treats indexes the same way it treats indexes, i.e. it drops and recreates the statistics. This means all statistics are reset, and we no longer try to preserve at least the functional dependencies. This should not be a major issue in practice, as the functional dependencies actually rely on per-column statistics, which were always reset anyway. Author: Tomas Vondra Reviewed-by: Justin Pryzby, Dean Rasheed, Zhihong Yu Discussion: https://postgr.es/m/ad7891d2-e90c-b446-9fe2-7419143847d7%40enterprisedb.com
2021-03-26Fix ndistinct estimates with system attributesTomas Vondra
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
2021-03-26Add "pg_database_owner" default role.Noah Misch
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
2021-03-26Merge similar algorithms into roles_is_member_of().Noah Misch
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
2021-03-25ALTER TABLE ... DETACH PARTITION ... CONCURRENTLYAlvaro Herrera
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
2021-03-24Fix stray double semicolonsPeter Eisentraut
Reported-by: John Naylor <john.naylor@enterprisedb.com>
2021-03-24Add date_bin functionPeter Eisentraut
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
2021-03-23Add bit_count SQL functionPeter Eisentraut
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
2021-03-19Allow configurable LZ4 TOAST compression.Robert Haas
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
2021-03-18Implement GROUP BY DISTINCTTomas Vondra
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
2021-03-18Fix function name in error hintMagnus Hagander
pg_read_file() is the function that's in core, pg_file_read() is in adminpack. But when using pg_file_read() in adminpack it calls the *C* level function pg_read_file() in core, which probably threw the original author off. But the error hint should be about the SQL function. Reported-By: Sergei Kornilov Backpatch-through: 11 Discussion: https://postgr.es/m/373021616060475@mail.yandex.ru
2021-03-10Avoid creating duplicate cached plans for inherited FK constraints.Tom Lane
When a foreign key constraint is applied to a partitioned table, each leaf partition inherits a similar FK constraint. We were processing all of those constraints independently, meaning that in large partitioning trees we'd build up large collections of cached FK-checking query plans. However, in all cases but one, the generated queries are actually identical for all members of the inheritance tree (because, in most cases, the query only mentions the topmost table of the other side of the FK relationship). So we can share a single cached plan among all the partitions, saving memory, not to mention time to build and maintain the cached plans. Keisuke Kuroda and Amit Langote Discussion: https://postgr.es/m/cab4b85d-9292-967d-adf2-be0d803c3e23@nttcom.co.jp_1
2021-03-09Track total amounts of times spent writing and syncing WAL data to disk.Fujii Masao
This commit adds new GUC track_wal_io_timing. When this is enabled, the total amounts of time XLogWrite writes and issue_xlog_fsync syncs WAL data to disk are counted in pg_stat_wal. This information would be useful to check how much WAL write and sync affect the performance. Enabling track_wal_io_timing will make the server query the operating system for the current time every time WAL is written or synced, which may cause significant overhead on some platforms. To avoid such additional overhead in the server with track_io_timing enabled, this commit introduces track_wal_io_timing as a separate parameter from track_io_timing. Note that WAL write and sync activity by walreceiver has not been tracked yet. This commit makes the server also track the numbers of times XLogWrite writes and issue_xlog_fsync syncs WAL data to disk, in pg_stat_wal, regardless of the setting of track_wal_io_timing. This counters can be used to calculate the WAL write and sync time per request, for example. Bump PGSTAT_FILE_FORMAT_ID. Bump catalog version. Author: Masahiro Ikeda Reviewed-By: Japin Li, Hayato Kuroda, Masahiko Sawada, David Johnston, Fujii Masao Discussion: https://postgr.es/m/0509ad67b585a5b86a83d445dfa75392@oss.nttdata.com
2021-03-09Remove support for SSL compressionMichael Paquier
PostgreSQL disabled compression as of e3bdb2d and the documentation recommends against using it since. Additionally, SSL compression has been disabled in OpenSSL since version 1.1.0, and was disabled in many distributions long before that. The most recent TLS version, TLSv1.3, disallows compression at the protocol level. This commit removes the feature itself, removing support for the libpq parameter sslcompression (parameter still listed for compatibility reasons with existing connection strings, just ignored), and removes the equivalent field in pg_stat_ssl and de facto PgBackendSSLStatus. Note that, on top of removing the ability to activate compression by configuration, compression is actively disabled in both frontend and backend to avoid overrides from local configurations. A TAP test is added for deprecated SSL parameters to check after backwards compatibility. Bump catalog version. Author: Daniel Gustafsson Reviewed-by: Peter Eisentraut, Magnus Hagander, Michael Paquier Discussion: https://postgr.es/m/7E384D48-11C5-441B-9EC3-F7DB1F8518F6@yesql.se
2021-03-03Add trim_array() function.Tom Lane
This has been in the SQL spec since 2008. It's a pretty thin wrapper around the array slice functionality, but the spec says we should have it, so here it is. Vik Fearing, reviewed by Dian Fay Discussion: https://postgr.es/m/fc92ce17-9655-8ff1-c62a-4dc4c8ccd815@postgresfriends.org
2021-03-01Improve reporting for syntax errors in multi-line JSON data.Tom Lane
Point to the specific line where the error was detected; the previous code tended to include several preceding lines as well. Avoid re-scanning the entire input to recompute which line that was. Simplify the logic a bit. Add test cases. Simon Riggs and Hamid Akhtar, reviewed by Daniel Gustafsson and myself Discussion: https://postgr.es/m/CANbhV-EPBnXm3MF_TTWBwwqgn1a1Ghmep9VHfqmNBQ8BT0f+_g@mail.gmail.com
2021-02-27Enhanced cycle mark valuesPeter Eisentraut
Per SQL:202x draft, in the CYCLE clause of a recursive query, the cycle mark values can be of type boolean and can be omitted, in which case they default to TRUE and FALSE. Reviewed-by: Vik Fearing <vik@postgresfriends.org> Discussion: https://www.postgresql.org/message-id/flat/db80ceee-6f97-9b4a-8ee8-3ba0c58e5be2@2ndquadrant.com
2021-02-26Revert "pg_collation_actual_version() -> pg_collation_current_version()."Thomas Munro
This reverts commit 9cf184cc0599b6e65e7e5ecd9d91cd42e278bcd8. Name change less well received than anticipated. Discussion: https://postgr.es/m/afcfb97e-88a1-a540-db95-6c573b93bc2b%40eisentraut.org
2021-02-24Fix some typos, grammar and style in docs and commentsMichael Paquier
The portions fixing the documentation are backpatched where needed. Author: Justin Pryzby Discussion: https://postgr.es/m/20210210235557.GQ20012@telsasoft.com backpatch-through: 9.6
2021-02-23Simplify printing of LSNsPeter Eisentraut
Add a macro LSN_FORMAT_ARGS for use in printf-style printing of LSNs. Convert all applicable code to use it. Reviewed-by: Ashutosh Bapat <ashutosh.bapat@enterprisedb.com> Reviewed-by: Kyotaro Horiguchi <horikyota.ntt@gmail.com> Reviewed-by: Michael Paquier <michael@paquier.xyz> Discussion: https://www.postgresql.org/message-id/flat/CAExHW5ub5NaTELZ3hJUCE6amuvqAtsSxc7O+uK7y4t9Rrk23cw@mail.gmail.com
2021-02-22Refactor get_collation_current_version().Thomas Munro
The code paths for three different OSes finished up with three different ways of excluding C[.xxx] and POSIX from consideration. Merge them. Reviewed-by: Michael Paquier <michael@paquier.xyz> Discussion: https://postgr.es/m/20210117215940.GE8560%40telsasoft.com
2021-02-22pg_collation_actual_version() -> pg_collation_current_version().Thomas Munro
The new name seems a bit more natural. Discussion: https://postgr.es/m/20210117215940.GE8560%40telsasoft.com
2021-02-22Hide internal error for pg_collation_actual_version(<bad OID>).Thomas Munro
Instead of an unsightly internal "cache lookup failed" message, just return NULL for bad OIDs, as is the convention for other similar things. Reported-by: Justin Pryzby <pryzby@telsasoft.com> Reviewed-by: Michael Paquier <michael@paquier.xyz> Discussion: https://postgr.es/m/20210117215940.GE8560%40telsasoft.com
2021-02-16Convert tsginidx.c's GIN indexing logic to fully ternary operation.Tom Lane
Commit 2f2007fbb did this partially, but there were two remaining warts. checkcondition_gin handled some uncertain cases by setting the out-of-band recheck flag, some by returning TS_MAYBE, and some by doing both. Meanwhile, TS_execute arbitrarily converted a TS_MAYBE result to TS_YES. Thus, if checkcondition_gin chose to only return TS_MAYBE, the outcome would be TS_YES with no recheck flag, potentially resulting in wrong query outputs. The case where this'd happen is if there were GIN_MAYBE entries in the indexscan results passed to gin_tsquery_[tri]consistent, which so far as I can see would only happen if the tidbitmap used to accumulate indexscan results grew large enough to become lossy. I initially thought of fixing this by ensuring we always set the recheck flag as well as returning TS_MAYBE in uncertain cases. But that errs in the other direction, potentially forcing rechecks of rows that provably match the query (since the recheck flag remains set even if TS_execute later finds that the answer must be TS_YES). Instead, let's get rid of the out-of-band recheck flag altogether and rely on returning TS_MAYBE. This requires exporting a version of TS_execute that will actually return the full ternary result of the evaluation ... but we likely should have done that to start with. Unfortunately it doesn't seem practical to add a regression test case that covers this: the amount of data needed to cause the GIN bitmap to become lossy results in a longer runtime than I think we want to have in the tests. (I'm wondering about allowing smaller work_mem settings to ameliorate that, but it'd be a matter for a separate patch.) Per bug #16865 from Dimitri Nüscheler. Back-patch to v13 where the faulty commit came in. Discussion: https://postgr.es/m/16865-4ffdc3e682e6d75b@postgresql.org
2021-02-15Display the time when the process started waiting for the lock, in pg_locks, ↵Fujii Masao
take 2 This commit adds new column "waitstart" into pg_locks view. This column reports the time when the server process started waiting for the lock if the lock is not held. This information is useful, for example, when examining the amount of time to wait on a lock by subtracting "waitstart" in pg_locks from the current time, and identify the lock that the processes are waiting for very long. This feature uses the current time obtained for the deadlock timeout timer as "waitstart" (i.e., the time when this process started waiting for the lock). Since getting the current time newly can cause overhead, we reuse the already-obtained time to avoid that overhead. Note that "waitstart" is updated without holding the lock table's partition lock, to avoid the overhead by additional lock acquisition. This can cause "waitstart" in pg_locks to become NULL for a very short period of time after the wait started even though "granted" is false. This is OK in practice because we can assume that users are likely to look at "waitstart" when waiting for the lock for a long time. The first attempt of this patch (commit 3b733fcd04) caused the buildfarm member "rorqual" (built with --disable-atomics --disable-spinlocks) to report the failure of the regression test. It was reverted by commit 890d2182a2. The cause of this failure was that the atomic variable for "waitstart" in the dummy process entry created at the end of prepare transaction was not initialized. This second attempt fixes that issue. Bump catalog version. Author: Atsushi Torikoshi Reviewed-by: Ian Lawrence Barwick, Robert Haas, Justin Pryzby, Fujii Masao Discussion: https://postgr.es/m/a96013dc51cdc56b2a2b84fa8a16a993@oss.nttdata.com
2021-02-15Add result size as argument of pg_cryptohash_final() for overflow checksMichael Paquier
With its current design, a careless use of pg_cryptohash_final() could would result in an out-of-bound write in memory as the size of the destination buffer to store the result digest is not known to the cryptohash internals, without the caller knowing about that. This commit adds a new argument to pg_cryptohash_final() to allow such sanity checks, and implements such defenses. The internals of SCRAM for HMAC could be tightened a bit more, but as everything is based on SCRAM_KEY_LEN with uses particular to this code there is no need to complicate its interface more than necessary, and this comes back to the refactoring of HMAC in core. Except that, this minimizes the uses of the existing DIGEST_LENGTH variables, relying instead on sizeof() for the result sizes. In ossp-uuid, this also makes the code more defensive, as it already relied on dce_uuid_t being at least the size of a MD5 digest. This is in philosophy similar to cfc40d3 for base64.c and aef8948 for hex.c. Reported-by: Ranier Vilela Author: Michael Paquier, Ranier Vilela Reviewed-by: Kyotaro Horiguchi Discussion: https://postgr.es/m/CAEudQAoqEGmcff3J4sTSV-R_16Monuz-UpJFbf_dnVH=APr02Q@mail.gmail.com
2021-02-12Avoid divide-by-zero in regex_selectivity() with long fixed prefix.Tom Lane
Given a regex pattern with a very long fixed prefix (approaching 500 characters), the result of pow(FIXED_CHAR_SEL, fixed_prefix_len) can underflow to zero. Typically the preceding selectivity calculation would have underflowed as well, so that we compute 0/0 and get NaN. In released branches this leads to an assertion failure later on. That doesn't happen in HEAD, for reasons I've not explored yet, but it's surely still a bug. To fix, just skip the division when the pow() result is zero, so that we'll (most likely) return a zero selectivity estimate. In the edge cases where "sel" didn't yet underflow, perhaps this isn't desirable, but I'm not sure that the case is worth spending a lot of effort on. The results of regex_selectivity_sub() are barely worth the electrons they're written on anyway :-( Per report from Alexander Lakhin. Back-patch to all supported versions. Discussion: https://postgr.es/m/6de0a0c3-ada9-cd0c-3e4e-2fa9964b41e3@gmail.com
2021-02-11Simplify jsonfuncs.c code by using strtoint() not strtol().Tom Lane
Explicitly testing for INT_MIN and INT_MAX isn't particularly good style; it's tedious and may draw useless compiler warnings on machines where int and long are the same width. We invented strtoint() precisely for this usage, so use that instead. While here, remove gratuitous variations in the way the tests for did-strtoint-succeed were spelled. Also, avoid attempting to negate INT_MIN; that would probably work given that the result is implicitly cast to uint32, but I think it's nominally undefined behavior. Per gripe from Ranier Vilela, though this isn't his proposed patch. Discussion: https://postgr.es/m/CAEudQAqge3QfzoBRhe59QrB_5g+NmQUj2QpzqZ9Nc7QepXGAEw@mail.gmail.com
2021-02-09Revert "Display the time when the process started waiting for the lock, in ↵Fujii Masao
pg_locks." This reverts commit 3b733fcd04195399db56f73f0616b4f5c6828e18. Per buildfarm members prion and rorqual.
2021-02-09Display the time when the process started waiting for the lock, in pg_locks.Fujii Masao
This commit adds new column "waitstart" into pg_locks view. This column reports the time when the server process started waiting for the lock if the lock is not held. This information is useful, for example, when examining the amount of time to wait on a lock by subtracting "waitstart" in pg_locks from the current time, and identify the lock that the processes are waiting for very long. This feature uses the current time obtained for the deadlock timeout timer as "waitstart" (i.e., the time when this process started waiting for the lock). Since getting the current time newly can cause overhead, we reuse the already-obtained time to avoid that overhead. Note that "waitstart" is updated without holding the lock table's partition lock, to avoid the overhead by additional lock acquisition. This can cause "waitstart" in pg_locks to become NULL for a very short period of time after the wait started even though "granted" is false. This is OK in practice because we can assume that users are likely to look at "waitstart" when waiting for the lock for a long time. Bump catalog version. Author: Atsushi Torikoshi Reviewed-by: Ian Lawrence Barwick, Robert Haas, Justin Pryzby, Fujii Masao Discussion: https://postgr.es/m/a96013dc51cdc56b2a2b84fa8a16a993@oss.nttdata.com
2021-02-02Build in some knowledge about foreign-key relationships in the catalogs.Tom Lane
This follows in the spirit of commit dfb75e478, which created primary key and uniqueness constraints to improve the visibility of constraints imposed on the system catalogs. While our catalogs contain many foreign-key-like relationships, they don't quite follow SQL semantics, in that the convention for an omitted reference is to write zero not NULL. Plus, we have some cases in which there are arrays each of whose elements is supposed to be an FK reference; SQL has no way to model that. So we can't create actual foreign key constraints to describe the situation. Nonetheless, we can collect and use knowledge about these relationships. This patch therefore adds annotations to the catalog header files to declare foreign-key relationships. (The BKI_LOOKUP annotations cover simple cases, but we weren't previously distinguishing which such columns are allowed to contain zeroes; we also need new markings for multi-column FK references.) Then, Catalog.pm and genbki.pl are taught to collect this information into a table in a new generated header "system_fk_info.h". The only user of that at the moment is a new SQL function pg_get_catalog_foreign_keys(), which exposes the table to SQL. The oidjoins regression test is rewritten to use pg_get_catalog_foreign_keys() to find out which columns to check. Aside from removing the need for manual maintenance of that test script, this allows it to cover numerous relationships that were not checked by the old implementation based on findoidjoins. (As of this commit, 217 relationships are checked by the test, versus 181 before.) Discussion: https://postgr.es/m/3240355.1612129197@sss.pgh.pa.us
2021-02-01SEARCH and CYCLE clausesPeter Eisentraut
This adds the SQL standard feature that adds the SEARCH and CYCLE clauses to recursive queries to be able to do produce breadth- or depth-first search orders and detect cycles. These clauses can be rewritten into queries using existing syntax, and that is what this patch does in the rewriter. Reviewed-by: Vik Fearing <vik@postgresfriends.org> Reviewed-by: Pavel Stehule <pavel.stehule@gmail.com> Discussion: https://www.postgresql.org/message-id/flat/db80ceee-6f97-9b4a-8ee8-3ba0c58e5be2@2ndquadrant.com
2021-02-01Get rid of unnecessary memory allocation in jsonb_subscript_assign()Alexander Korotkov
Current code allocates memory for JsonbValue, but it could be placed locally.
2021-02-01Fix portability issue in new jsonbsubs code.Tom Lane
On machines where sizeof(Datum) > sizeof(Oid) (that is, any 64-bit platform), the previous coding would compute a misaligned workspace->index pointer if nupper is odd. Architectures where misaligned access is a hard no-no would then fail. This appears to explain why thorntail is unhappy but other buildfarm members are not.
2021-01-31Throw error when assigning jsonb scalar instead of a composite objectAlexander Korotkov
During the jsonb subscripting assignment, the provided path might assume an object or an array where the source jsonb has a scalar value. Initial subscripting assignment logic will skip such an update operation with no message shown. This commit makes it throw an error to indicate this type of situation. Discussion: https://postgr.es/m/CA%2Bq6zcV8qvGcDXurwwgUbwACV86Th7G80pnubg42e-p9gsSf%3Dg%40mail.gmail.com Discussion: https://postgr.es/m/CA%2Bq6zcX3mdxGCgdThzuySwH-ApyHHM-G4oB1R0fn0j2hZqqkLQ%40mail.gmail.com Discussion: https://postgr.es/m/CA%2Bq6zcVDuGBv%3DM0FqBYX8DPebS3F_0KQ6OVFobGJPM507_SZ_w%40mail.gmail.com Discussion: https://postgr.es/m/CA%2Bq6zcVovR%2BXY4mfk-7oNk-rF91gH0PebnNfuUjuuDsyHjOcVA%40mail.gmail.com Author: Dmitry Dolgov Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay Reviewed-by: Andrew Dunstan, Chapman Flack, Merlin Moncure, Peter Geoghegan Reviewed-by: Alvaro Herrera, Jim Nasby, Josh Berkus, Victor Wagner Reviewed-by: Aleksander Alekseev, Robert Haas, Oleg Bartunov
2021-01-31Filling array gaps during jsonb subscriptingAlexander Korotkov
This commit introduces two new flags for jsonb assignment: * JB_PATH_FILL_GAPS: Appending array elements on the specified position, gaps are filled with nulls (similar to the JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * JB_PATH_CONSISTENT_POSITION: Assigning keeps array positions consistent by preventing prepending of elements. Both flags are used only in jsonb subscripting assignment. Initially proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. Discussion: https://postgr.es/m/CA%2Bq6zcV8qvGcDXurwwgUbwACV86Th7G80pnubg42e-p9gsSf%3Dg%40mail.gmail.com Discussion: https://postgr.es/m/CA%2Bq6zcX3mdxGCgdThzuySwH-ApyHHM-G4oB1R0fn0j2hZqqkLQ%40mail.gmail.com Discussion: https://postgr.es/m/CA%2Bq6zcVDuGBv%3DM0FqBYX8DPebS3F_0KQ6OVFobGJPM507_SZ_w%40mail.gmail.com Discussion: https://postgr.es/m/CA%2Bq6zcVovR%2BXY4mfk-7oNk-rF91gH0PebnNfuUjuuDsyHjOcVA%40mail.gmail.com Author: Dmitry Dolgov Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay Reviewed-by: Andrew Dunstan, Chapman Flack, Merlin Moncure, Peter Geoghegan Reviewed-by: Alvaro Herrera, Jim Nasby, Josh Berkus, Victor Wagner Reviewed-by: Aleksander Alekseev, Robert Haas, Oleg Bartunov
2021-01-31Implementation of subscripting for jsonbAlexander Korotkov
Subscripting for jsonb does not support slices, does not have a limit for the number of subscripts, and an assignment expects a replace value to have jsonb type. There is also one functional difference between assignment via subscripting and assignment via jsonb_set(). When an original jsonb container is NULL, the subscripting replaces it with an empty jsonb and proceeds with an assignment. For the sake of code reuse, we rearrange some parts of jsonb functionality to allow the usage of the same functions for jsonb_set and assign subscripting operation. The original idea belongs to Oleg Bartunov. Catversion is bumped. Discussion: https://postgr.es/m/CA%2Bq6zcV8qvGcDXurwwgUbwACV86Th7G80pnubg42e-p9gsSf%3Dg%40mail.gmail.com Discussion: https://postgr.es/m/CA%2Bq6zcX3mdxGCgdThzuySwH-ApyHHM-G4oB1R0fn0j2hZqqkLQ%40mail.gmail.com Discussion: https://postgr.es/m/CA%2Bq6zcVDuGBv%3DM0FqBYX8DPebS3F_0KQ6OVFobGJPM507_SZ_w%40mail.gmail.com Discussion: https://postgr.es/m/CA%2Bq6zcVovR%2BXY4mfk-7oNk-rF91gH0PebnNfuUjuuDsyHjOcVA%40mail.gmail.com Author: Dmitry Dolgov Reviewed-by: Tom Lane, Arthur Zakirov, Pavel Stehule, Dian M Fay Reviewed-by: Andrew Dunstan, Chapman Flack, Merlin Moncure, Peter Geoghegan Reviewed-by: Alvaro Herrera, Jim Nasby, Josh Berkus, Victor Wagner Reviewed-by: Aleksander Alekseev, Robert Haas, Oleg Bartunov
2021-01-28Refactor SQL functions of SHA-2 in cryptohashfuncs.cMichael Paquier
The same code pattern was repeated four times when compiling a SHA-2 hash. This refactoring has the advantage to issue a compilation warning if a new value is added to pg_cryptohash_type, so as anybody doing an addition in this area would need to consider if support for a new SQL function is needed or not. Author: Sehrope Sarkuni, Michael Paquier Discussion: https://postgr.es/m/YA7DvLRn2xnTgsMc@paquier.xyz
2021-01-25Fix broken ruleutils support for function TRANSFORM clauses.Tom Lane
I chanced to notice that this dumped core due to a faulty Assert. To add insult to injury, the output has been misformatted since v11. Obviously we need some regression testing here. Discussion: https://postgr.es/m/d1cc628c-3953-4209-957b-29427acc38c8@www.fastmail.com
2021-01-21Fix pull_varnos' miscomputation of relids set for a PlaceHolderVar.Tom Lane
Previously, pull_varnos() took the relids of a PlaceHolderVar as being equal to the relids in its contents, but that fails to account for the possibility that we have to postpone evaluation of the PHV due to outer joins. This could result in a malformed plan. The known cases end up triggering the "failed to assign all NestLoopParams to plan nodes" sanity check in createplan.c, but other symptoms may be possible. The right value to use is the join level we actually intend to evaluate the PHV at. We can get that from the ph_eval_at field of the associated PlaceHolderInfo. However, there are some places that call pull_varnos() before the PlaceHolderInfos have been created; in that case, fall back to the conservative assumption that the PHV will be evaluated at its syntactic level. (In principle this might result in missing some legal optimization, but I'm not aware of any cases where it's an issue in practice.) Things are also a bit ticklish for calls occurring during deconstruct_jointree(), but AFAICS the ph_eval_at fields should have reached their final values by the time we need them. The main problem in making this work is that pull_varnos() has no way to get at the PlaceHolderInfos. We can fix that easily, if a bit tediously, in HEAD by passing it the planner "root" pointer. In the back branches that'd cause an unacceptable API/ABI break for extensions, so leave the existing entry points alone and add new ones with the additional parameter. (If an old entry point is called and encounters a PHV, it'll fall back to using the syntactic level, again possibly missing some valid optimization.) Back-patch to v12. The computation is surely also wrong before that, but it appears that we cannot reach a bad plan thanks to join order restrictions imposed on the subquery that the PlaceHolderVar came from. The error only became reachable when commit 4be058fe9 allowed trivial subqueries to be collapsed out completely, eliminating their join order restrictions. Per report from Stephan Springl. Discussion: https://postgr.es/m/171041.1610849523@sss.pgh.pa.us
2021-01-18Add bytea equivalents of ltrim() and rtrim().Tom Lane
We had bytea btrim() already, but for some reason not the other two. Joel Jacobson Discussion: https://postgr.es/m/d10cd5cd-a901-42f1-b832-763ac6f7ff3a@www.fastmail.com