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2020-09-28Add for_each_from, to simplify loops starting from non-first list cells.Tom Lane
We have a dozen or so places that need to iterate over all but the first cell of a List. Prior to v13 this was typically written as for_each_cell(lc, lnext(list_head(list))) Commit 1cff1b95a changed these to for_each_cell(lc, list, list_second_cell(list)) This patch introduces a new macro for_each_from() which expresses the start point as a list index, allowing these to be written as for_each_from(lc, list, 1) This is marginally more efficient, since ForEachState.i can be initialized directly instead of backing into it from a ListCell address. It also seems clearer and less typo-prone. Some of the remaining uses of for_each_cell() look like they could profitably be changed to for_each_from(), but here I confined myself to changing uses of list_second_cell(). Also, fix for_each_cell_setup() and for_both_cell_setup() to const-ify their arguments; that's a simple oversight in 1cff1b95a. Back-patch into v13, on the grounds that (1) the const-ification is a minor bug fix, and (2) it's better for back-patching purposes if we only have two ways to write these loops rather than three. In HEAD, also remove list_third_cell() and list_fourth_cell(), which were also introduced in 1cff1b95a, and are unused as of cc99baa43. It seems unlikely that any third-party code would have started to use them already; anyone who has can be directed to list_nth_cell instead. Discussion: https://postgr.es/m/CAApHDvpo1zj9KhEpU2cCRZfSM3Q6XGdhzuAS2v79PH7WJBkYVA@mail.gmail.com
2020-09-28Assign collations in partition bound expressions.Tom Lane
Failure to do this can result in errors during evaluation of the bound expression, as illustrated by the new regression test. Back-patch to v12 where the ability for partition bounds to be expressions was added. Discussion: https://postgr.es/m/CAJV4CdrZ5mKuaEsRSbLf2URQ3h6iMtKD=hik8MaF5WwdmC9uZw@mail.gmail.com
2020-09-28Remove complaints about COLLATE clauses in partition bound values.Tom Lane
transformPartitionBoundValue went out of its way to do the wrong thing: there is no reason to complain about a non-matching COLLATE clause in a partition boundary expression. We're coercing the bound expression to the target column type as though by an implicit assignment, and the rules for implicit assignment say that collations can be implicitly converted. What we *do* need to do, and the code is not doing, is apply assign_expr_collations() to the bound expression. While this is merely a definition disagreement, that is a bug that needs to be back-patched, so I'll commit it separately. Discussion: https://postgr.es/m/CAJV4CdrZ5mKuaEsRSbLf2URQ3h6iMtKD=hik8MaF5WwdmC9uZw@mail.gmail.com
2020-09-23Improve error cursor positions for problems with partition bounds.Tom Lane
We failed to pass down the query string to check_new_partition_bound, so that its attempts to provide error cursor positions were for naught; one must have the query string to get parser_errposition to do anything. Adjust its API to require a ParseState to be passed down. Also, improve the logic inside check_new_partition_bound so that the cursor points at the partition bound for the specific column causing the issue, when one can be identified. That part is also for naught if we can't determine the query position of the column with the problem. Improve transformPartitionBoundValue so that it makes sure that const-simplified partition expressions will be properly labeled with positions. In passing, skip calling evaluate_expr if the value is already a Const, which is surely the most common case. Alexandra Wang, Ashwin Agrawal, Amit Langote; reviewed by Ashutosh Bapat Discussion: https://postgr.es/m/CACiyaSopZoqssfMzgHk6fAkp01cL6vnqBdmTw2C5_KJaFR_aMg@mail.gmail.com Discussion: https://postgr.es/m/CAJV4CdrZ5mKuaEsRSbLf2URQ3h6iMtKD=hik8MaF5WwdmC9uZw@mail.gmail.com
2020-09-22Improve the error message for an inappropriate column definition list.Tom Lane
The existing message about "a column definition list is only allowed for functions returning "record"" could be given in some cases where it was fairly confusing; in particular, a function with multiple OUT parameters *does* return record according to pg_proc. Break it down into a couple more cases to deliver a more on-point complaint. Per complaint from Bruce Momjian. Discussion: https://postgr.es/m/798909.1600562993@sss.pgh.pa.us
2020-09-21Standardize order of use strict and use warnings in Perl codePeter Eisentraut
The standard order in PostgreSQL and other code is use strict first, but some code was uselessly inconsistent about this.
2020-09-19Remove precedence hacks no longer needed without postfix operators.Tom Lane
It's no longer necessary to assign explicit precedences to GENERATED, NULL_P, PRESERVE, or STRIP_P. Actually, we don't need to assign precedence to IDENT either; that was really just there to govern the behavior of target_el's "a_expr IDENT" production, which no longer ends with that terminal. However, it seems like a good idea to continue to do so, because it provides a reference point for a precedence level that we can assign to other unreserved keywords that lack a natural precedence level. Research by Peter Eisentraut and John Naylor; comment rewrite by me. Discussion: https://postgr.es/m/38ca86db-42ab-9b48-2902-337a0d6b8311@2ndquadrant.com
2020-09-18Allow most keywords to be used as column labels without requiring AS.Tom Lane
Up to now, if you tried to omit "AS" before a column label in a SELECT list, it would only work if the column label was an IDENT, that is not any known keyword. This is rather unfriendly considering that we have so many keywords and are constantly growing more. In the wake of commit 1ed6b8956 it's possible to improve matters quite a bit. We'd originally tried to make this work by having some of the existing keyword categories be allowed without AS, but that didn't work too well, because each category contains a few special cases that don't work without AS. Instead, invent an entirely orthogonal keyword property "can be bare column label", and mark all keywords that way for which we don't get shift/reduce errors by doing so. It turns out that of our 450 current keywords, all but 39 can be made bare column labels, improving the situation by over 90%. This number might move around a little depending on future grammar work, but it's a pretty nice improvement. Mark Dilger, based on work by myself and Robert Haas; review by John Naylor Discussion: https://postgr.es/m/38ca86db-42ab-9b48-2902-337a0d6b8311@2ndquadrant.com
2020-09-17Remove support for postfix (right-unary) operators.Tom Lane
This feature has been a thorn in our sides for a long time, causing many grammatical ambiguity problems. It doesn't seem worth the pain to continue to support it, so remove it. There are some follow-on improvements we can make in the grammar, but this commit only removes the bare minimum number of productions, plus assorted backend support code. Note that pg_dump and psql continue to have full support, since they may be used against older servers. However, pg_dump warns about postfix operators. There is also a check in pg_upgrade. Documentation-wise, I (tgl) largely removed the "left unary" terminology in favor of saying "prefix operator", which is a more standard and IMO less confusing term. I included a catversion bump, although no initial catalog data changes here, to mark the boundary at which oprkind = 'r' stopped being valid in pg_operator. Mark Dilger, based on work by myself and Robert Haas; review by John Naylor Discussion: https://postgr.es/m/38ca86db-42ab-9b48-2902-337a0d6b8311@2ndquadrant.com
2020-09-17Allow CURRENT_ROLE where CURRENT_USER is acceptedPeter Eisentraut
In the particular case of GRANTED BY, this is specified in the SQL standard. Since in PostgreSQL, CURRENT_ROLE is equivalent to CURRENT_USER, and CURRENT_USER is already supported here, adding CURRENT_ROLE is trivial. The other cases are PostgreSQL extensions, but for the same reason it also makes sense there. Reviewed-by: Vik Fearing <vik@postgresfriends.org> Reviewed-by: Asif Rehman <asifr.rehman@gmail.com> Reviewed-by: Alvaro Herrera <alvherre@2ndquadrant.com> Discussion: https://www.postgresql.org/message-id/flat/f2feac44-b4c5-f38f-3699-2851d6a76dc9%402ndquadrant.com
2020-09-14Message fixes and style improvementsPeter Eisentraut
2020-09-07Clarify comments in enforce_generic_type_consistency().Tom Lane
Some of the pre-existing comments were vague about whether they referred to all polymorphic types or only the old-style ones. Also be more consistent about using the "family 1" vs "family 2" terminology. Himanshu Upadhyaya and Tom Lane Discussion: https://postgr.es/m/CAPF61jBUg9XoMPNuLpoZ+h6UZ2VxKdNt3rQL1xw1GOBwjWzAXQ@mail.gmail.com
2020-09-04Remove some more useless assignments.Tom Lane
Found with clang's scan-build tool. It also whines about a lot of other dead stores that we should *not* change IMO, either as a matter of style or future-proofing. But these places seem like clear oversights. Discussion: https://postgr.es/m/CAEudQAo1+AcGppxDSg8k+zF4+Kv+eJyqzEDdbpDg58-=MQcerQ@mail.gmail.com
2020-09-04Remove variable "concurrent" from ReindexStmtMichael Paquier
This node already handles multiple options using a bitmask, so having a separate boolean flag is not necessary. This simplifies the code a bit with less arguments to give to the reindex routines, by replacing the boolean with an equivalent bitmask value. Reviewed-by: Julien Rouhaud Discussion: https://postgr.es/m/20200902110326.GA14963@paquier.xyz
2020-08-21Fix handling of CREATE TABLE LIKE with inheritance.Tom Lane
If a CREATE TABLE command uses both LIKE and traditional inheritance, Vars in CHECK constraints and expression indexes that are absorbed from a LIKE parent table tended to get mis-numbered, resulting in wrong answers and/or bizarre error messages (though probably not any actual crashes, thanks to validation occurring in the executor). In v12 and up, the same could happen to Vars in GENERATED expressions, even in cases with no LIKE clause but multiple traditional-inheritance parents. The cause of the problem for LIKE is that parse_utilcmd.c supposed it could renumber such Vars correctly during transformCreateStmt(), which it cannot since we have not yet accounted for columns added via inheritance. Fix that by postponing processing of LIKE INCLUDING CONSTRAINTS, DEFAULTS, GENERATED, INDEXES till after we've performed DefineRelation(). The error with GENERATED and multiple inheritance is a simple oversight in MergeAttributes(); it knows it has to renumber Vars in inherited CHECK constraints, but forgot to apply the same processing to inherited GENERATED expressions (a/k/a defaults). Per bug #16272 from Tom Gottfried. The non-GENERATED variants of the issue are ancient, presumably dating right back to the addition of CREATE TABLE LIKE; hence back-patch to all supported branches. Discussion: https://postgr.es/m/16272-6e32da020e9a9381@postgresql.org
2020-07-11Rename field "relkind" to "objtype" for CTAS and ALTER TABLE nodesMichael Paquier
"relkind" normally refers to the char field from pg_class. However, in the parse nodes AlterTableStmt and CreateTableAsStmt, "relkind" was used for a field of type enum ObjectType, that could refer to other object types than those possible for a relkind. Such fields being usually named "objtype", switch the name in both structures to make things more consistent. Note that this led to some confusion in functions that also operate on a RangeTableEntry object, which also has a field named "relkind". This naming goes back to commit 09d4e96, where only OBJECT_TABLE and OBJECT_INDEX were used. This got extended later to use as well OBJECT_TYPE with e440e12, not really a relation kind. Author: Mark Dilger Reviewed-by: Daniel Gustafsson, Álvaro Herrera, Michael Paquier Discussion: https://postgr.es/m/609181AE-E399-47C7-9221-856E0F96BF93@enterprisedb.com
2020-07-08code: replace most remaining uses of 'master'.Andres Freund
Author: Andres Freund Reviewed-By: David Steele Discussion: https://postgr.es/m/20200615182235.x7lch5n6kcjq4aue@alap3.anarazel.de
2020-06-29Mop up some no-longer-necessary hacks around printf %.*s format.Tom Lane
Commit 54cd4f045 added some kluges to work around an old glibc bug, namely that %.*s could misbehave if glibc thought any characters in the supplied string were incorrectly encoded. Now that we use our own snprintf.c implementation, we need not worry about that bug (even if it still exists in the wild). Revert a couple of particularly ugly hacks, and remove or improve assorted comments. Note that there can still be encoding-related hazards here: blindly clipping at a fixed length risks producing wrongly-encoded output if the clip splits a multibyte character. However, code that's doing correct multibyte-aware clipping doesn't really need a comment about that, while code that isn't needs an explanation why not, rather than a red-herring comment about an obsolete bug. Discussion: https://postgr.es/m/279428.1593373684@sss.pgh.pa.us
2020-06-29Add current substring regular expression syntaxPeter Eisentraut
SQL:1999 had syntax SUBSTRING(text FROM pattern FOR escapechar) but this was replaced in SQL:2003 by the more clear SUBSTRING(text SIMILAR pattern ESCAPE escapechar) but this was never implemented in PostgreSQL. This patch adds that new syntax as an alternative in the parser, and updates documentation and tests to indicate that this is the preferred alternative now. Reviewed-by: Pavel Stehule <pavel.stehule@gmail.com> Reviewed-by: Vik Fearing <vik@postgresfriends.org> Reviewed-by: Fabien COELHO <coelho@cri.ensmp.fr> Discussion: https://www.postgresql.org/message-id/flat/a15db31c-d0f8-8ce0-9039-578a31758adb%402ndquadrant.com
2020-06-29Clean up grammar a bitPeter Eisentraut
Simplify the grammar specification of substring() and overlay() a bit, simplify and update some comments. Reviewed-by: Pavel Stehule <pavel.stehule@gmail.com> Reviewed-by: Vik Fearing <vik@postgresfriends.org> Reviewed-by: Fabien COELHO <coelho@cri.ensmp.fr> Discussion: https://www.postgresql.org/message-id/flat/a15db31c-d0f8-8ce0-9039-578a31758adb%402ndquadrant.com
2020-06-13Refactor AlterExtensionContentsStmt grammarPeter Eisentraut
Make use of the general object support already used by COMMENT, DROP, and SECURITY LABEL. Discussion: https://www.postgresql.org/message-id/flat/163c00a5-f634-ca52-fc7c-0e53deda8735%402ndquadrant.com
2020-06-13Grammar object type refactoringPeter Eisentraut
Unify the grammar of COMMENT, DROP, and SECURITY LABEL further. They all effectively just take an object address for later processing, so we can make the grammar more generalized. Some extra checking about which object types are supported can be done later in the statement execution. Discussion: https://www.postgresql.org/message-id/flat/163c00a5-f634-ca52-fc7c-0e53deda8735%402ndquadrant.com
2020-06-11Refactor DROP LANGUAGE grammarPeter Eisentraut
Fold it into the generic DropStmt. Discussion: https://www.postgresql.org/message-id/flat/163c00a5-f634-ca52-fc7c-0e53deda8735%402ndquadrant.com
2020-06-11Remove deprecated syntax from CREATE/DROP LANGUAGEPeter Eisentraut
Remove the option to specify the language name as a single-quoted string. This has been obsolete since ee8ed85da3b. Removing it allows better grammar refactoring. The syntax of the CREATE FUNCTION LANGUAGE clause is not changed. Discussion: https://www.postgresql.org/message-id/flat/163c00a5-f634-ca52-fc7c-0e53deda8735%402ndquadrant.com
2020-06-11Fold AlterForeignTableStmt into AlterTableStmtPeter Eisentraut
All other relation types are handled by AlterTableStmt, so it's unnecessary to make a different statement for foreign tables. Discussion: https://www.postgresql.org/message-id/flat/163c00a5-f634-ca52-fc7c-0e53deda8735%402ndquadrant.com
2020-06-10Remove redundant grammar symbolsPeter Eisentraut
access_method, database_name, and index_name are all just name, and they are not used consistently for their alleged purpose, so remove them. They have been around since ancient times but have no current reason for existing. Removing them can simplify future grammar refactoring. Discussion: https://www.postgresql.org/message-id/flat/163c00a5-f634-ca52-fc7c-0e53deda8735%402ndquadrant.com
2020-05-19part_strategy does not need its very own keyword classification.Tom Lane
This should be plain old ColId. Making it so makes the grammar less complicated, and makes the compiled tables a kilobyte or so smaller (likely because they don't have to deal with a keyword classification that's not used anyplace else).
2020-05-18WITH TIES: number of rows is optional and defaults to oneAlvaro Herrera
FETCH FIRST .. ONLY implements this correctly, but we missed to include it for FETCH FIRST .. WITH TIES in commit 357889eb17bb. Author: Vik Fearing Discussion: https://postgr.es/m/6aa690ef-551d-e24f-2690-c38c2442947c@postgresfriends.org
2020-05-16Run pgindent with new pg_bsd_indent version 2.1.1.Tom Lane
Thomas Munro fixed a longstanding annoyance in pg_bsd_indent, that it would misformat lines containing IsA() macros on the assumption that the IsA() call should be treated like a cast. This improves some other cases involving field/variable names that match typedefs, too. The only places that get worse are a couple of uses of the OpenSSL macro STACK_OF(); we'll gladly take that trade-off. Discussion: https://postgr.es/m/20200114221814.GA19630@alvherre.pgsql
2020-05-14Initial pgindent and pgperltidy run for v13.Tom Lane
Includes some manual cleanup of places that pgindent messed up, most of which weren't per project style anyway. Notably, it seems some people didn't absorb the style rules of commit c9d297751, because there were a bunch of new occurrences of function calls with a newline just after the left paren, all with faulty expectations about how the rest of the call would get indented.
2020-05-13Dial back -Wimplicit-fallthrough to level 3Alvaro Herrera
The additional pain from level 4 is excessive for the gain. Also revert all the source annotation changes to their original wordings, to avoid back-patching pain. Discussion: https://postgr.es/m/31166.1589378554@sss.pgh.pa.us
2020-05-12Add -Wimplicit-fallthrough to CFLAGS and CXXFLAGSAlvaro Herrera
Use it at level 4, a bit more restrictive than the default level, and tweak our commanding comments to FALLTHROUGH. (However, leave zic.c alone, since it's external code; to avoid the warnings that would appear there, change CFLAGS for that file in the Makefile.) Author: Julien Rouhaud <rjuju123@gmail.com> Author: Álvaro Herrera <alvherre@alvh.no-ip.org> Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us> Discussion: https://postgr.es/m/20200412081825.qyo5vwwco3fv4gdo@nol Discussion: https://postgr.es/m/flat/E1fDenm-0000C8-IJ@gemulon.postgresql.org
2020-04-20Add ALTER .. NO DEPENDS ONAlvaro Herrera
Commit f2fcad27d59c (9.6 era) added the ability to mark objects as dependent an extension, but forgot to add a way for such dependencies to be removed. This commit fixes that oversight. Strictly speaking this should be backpatched to 9.6, but due to lack of demand we're not doing so at this time. Discussion: https://postgr.es/m/20200217225333.GA30974@alvherre.pgsql Reviewed-by: ahsan hadi <ahsan.hadi@gmail.com> Reviewed-by: Ibrar Ahmed <ibrar.ahmad@gmail.com> Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
2020-04-09Fix CREATE TABLE LIKE INCLUDING GENERATED column order issuePeter Eisentraut
CREATE TABLE LIKE INCLUDING GENERATED would fail if a generated column referred to a column with a higher attribute number. This is because the column mapping mechanism created the mapping incrementally as columns are added. This was sufficient for previous uses of that mechanism (omitting dropped columns), and it also happened to work if generated columns only referred to columns with lower attribute numbers, but here it failed. This fix is to build the attribute mapping in a separate loop before processing the columns in detail. Bug: #16342 Reported-by: Ethan Waldo <ewaldo@healthetechs.com> Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
2020-04-08Revert 0f5ca02f53Alexander Korotkov
0f5ca02f53 introduces 3 new keywords. It appears to be too much for relatively small feature. Given now we past feature freeze, it's already late for discussion of the new syntax. So, revert. Discussion: https://postgr.es/m/28209.1586294824%40sss.pgh.pa.us
2020-04-08Fix crash when using COLLATE in partition bound expressionsMichael Paquier
Attempting to use a COLLATE clause with a type that it not collatable in a partition bound expression could crash the server. This commit fixes the code by adding more checks similar to what is done when computing index or partition attributes by making sure that there is a collation iff the type is collatable. Backpatch down to 12, as 7c079d7 introduced this problem. Reported-by: Alexander Lakhin Author: Dmitry Dolgov Discussion: https://postgr.es/m/16325-809194cf742313ab@postgresql.org Backpatch-through: 12
2020-04-08Put back mistakenly removed #include.Tom Lane
In commit 4dbcb3f84 I removed some code from parse_coerce.c, and also removed some apparently-no-longer-needed #includes. But removing datum.h broke some not-compiled-by-default code. Discussion: https://postgr.es/m/20200407205436.pyjhddw5bn5upvsu@development
2020-04-07Implement waiting for given lsn at transaction startAlexander Korotkov
This commit adds following optional clause to BEGIN and START TRANSACTION commands. WAIT FOR LSN lsn [ TIMEOUT timeout ] New clause pospones transaction start till given lsn is applied on standby. This clause allows user be sure, that changes previously made on primary would be visible on standby. New shared memory struct is used to track awaited lsn per backend. Recovery process wakes up backend once required lsn is applied. Author: Ivan Kartyshov, Anna Akenteva Reviewed-by: Craig Ringer, Thomas Munro, Robert Haas, Kyotaro Horiguchi Reviewed-by: Masahiko Sawada, Ants Aasma, Dmitry Ivanov, Simon Riggs Reviewed-by: Amit Kapila, Alexander Korotkov Discussion: https://postgr.es/m/0240c26c-9f84-30ea-fca9-93ab2df5f305%40postgrespro.ru
2020-04-07Support FETCH FIRST WITH TIESAlvaro Herrera
WITH TIES is an option to the FETCH FIRST N ROWS clause (the SQL standard's spelling of LIMIT), where you additionally get rows that compare equal to the last of those N rows by the columns in the mandatory ORDER BY clause. There was a proposal by Andrew Gierth to implement this functionality in a more powerful way that would yield more features, but the other patch had not been finished at this time, so we decided to use this one for now in the spirit of incremental development. Author: Surafel Temesgen <surafel3000@gmail.com> Reviewed-by: Álvaro Herrera <alvherre@alvh.no-ip.org> Reviewed-by: Tomas Vondra <tomas.vondra@2ndquadrant.com> Discussion: https://postgr.es/m/CALAY4q9ky7rD_A4vf=FVQvCGngm3LOes-ky0J6euMrg=_Se+ag@mail.gmail.com Discussion: https://postgr.es/m/87o8wvz253.fsf@news-spur.riddles.org.uk
2020-04-04Remove bogus Assert, add some regression test cases showing why.Tom Lane
Commit 77ec5affb added an assertion to enforce_generic_type_consistency that boils down to "if the function result is polymorphic, there must be at least one polymorphic argument". This should be true for user-created functions, but there are built-in functions for which it's not true, as pointed out by Jaime Casanova. Hence, go back to the old behavior of leaving the return type alone. There's only a limited amount of stuff you can do with such a function result, but it does work to some extent; add some regression test cases to ensure we don't break that again. Discussion: https://postgr.es/m/CAJGNTeMbhtsCUZgJJ8h8XxAJbK7U2ipsX8wkHRtZRz-NieT8RA@mail.gmail.com
2020-04-04Skip WAL for new relfilenodes, under wal_level=minimal.Noah Misch
Until now, only selected bulk operations (e.g. COPY) did this. If a given relfilenode received both a WAL-skipping COPY and a WAL-logged operation (e.g. INSERT), recovery could lose tuples from the COPY. See src/backend/access/transam/README section "Skipping WAL for New RelFileNode" for the new coding rules. Maintainers of table access methods should examine that section. To maintain data durability, just before commit, we choose between an fsync of the relfilenode and copying its contents to WAL. A new GUC, wal_skip_threshold, guides that choice. If this change slows a workload that creates small, permanent relfilenodes under wal_level=minimal, try adjusting wal_skip_threshold. Users setting a timeout on COMMIT may need to adjust that timeout, and log_min_duration_statement analysis will reflect time consumption moving to COMMIT from commands like COPY. Internally, this requires a reliable determination of whether RollbackAndReleaseCurrentSubTransaction() would unlink a relation's current relfilenode. Introduce rd_firstRelfilenodeSubid. Amend the specification of rd_createSubid such that the field is zero when a new rel has an old rd_node. Make relcache.c retain entries for certain dropped relations until end of transaction. Bump XLOG_PAGE_MAGIC, since this introduces XLOG_GIST_ASSIGN_LSN. Future servers accept older WAL, so this bump is discretionary. Kyotaro Horiguchi, reviewed (in earlier, similar versions) by Robert Haas. Heikki Linnakangas and Michael Paquier implemented earlier designs that materially clarified the problem. Reviewed, in earlier designs, by Andrew Dunstan, Andres Freund, Alvaro Herrera, Tom Lane, Fujii Masao, and Simon Riggs. Reported by Martijn van Oosterhout. Discussion: https://postgr.es/m/20150702220524.GA9392@svana.org
2020-04-02Add SQL functions for Unicode normalizationPeter Eisentraut
This adds SQL expressions NORMALIZE() and IS NORMALIZED to convert and check Unicode normal forms, per SQL standard. To support fast IS NORMALIZED tests, we pull in a new data file DerivedNormalizationProps.txt from Unicode and build a lookup table from that, using techniques similar to ones already used for other Unicode data. make update-unicode will keep it up to date. We only build and use these tables for the NFC and NFKC forms, because they are too big for NFD and NFKD and the improvement is not significant enough there. Reviewed-by: Daniel Verite <daniel@manitou-mail.org> Reviewed-by: Andreas Karlsson <andreas@proxel.se> Discussion: https://www.postgresql.org/message-id/flat/c1909f27-c269-2ed9-12f8-3ab72c8caf7a@2ndquadrant.com
2020-03-30Implement operator class parametersAlexander Korotkov
PostgreSQL provides set of template index access methods, where opclasses have much freedom in the semantics of indexing. These index AMs are GiST, GIN, SP-GiST and BRIN. There opclasses define representation of keys, operations on them and supported search strategies. So, it's natural that opclasses may be faced some tradeoffs, which require user-side decision. This commit implements opclass parameters allowing users to set some values, which tell opclass how to index the particular dataset. This commit doesn't introduce new storage in system catalog. Instead it uses pg_attribute.attoptions, which is used for table column storage options but unused for index attributes. In order to evade changing signature of each opclass support function, we implement unified way to pass options to opclass support functions. Options are set to fn_expr as the constant bytea expression. It's possible due to the fact that opclass support functions are executed outside of expressions, so fn_expr is unused for them. This commit comes with some examples of opclass options usage. We parametrize signature length in GiST. That applies to multiple opclasses: tsvector_ops, gist__intbig_ops, gist_ltree_ops, gist__ltree_ops, gist_trgm_ops and gist_hstore_ops. Also we parametrize maximum number of integer ranges for gist__int_ops. However, the main future usage of this feature is expected to be json, where users would be able to specify which way to index particular json parts. Catversion is bumped. Discussion: https://postgr.es/m/d22c3a18-31c7-1879-fc11-4c1ce2f5e5af%40postgrespro.ru Author: Nikita Glukhov, revised by me Reviwed-by: Nikolay Shaplov, Robert Haas, Tom Lane, Tomas Vondra, Alvaro Herrera
2020-03-25Go back to returning int from ereport auxiliary functions.Tom Lane
This reverts the parts of commit 17a28b03645e27d73bf69a95d7569b61e58f06eb that changed ereport's auxiliary functions from returning dummy integer values to returning void. It turns out that a minority of compilers complain (not entirely unreasonably) about constructs such as (condition) ? errdetail(...) : 0 if errdetail() returns void rather than int. We could update those call sites to say "(void) 0" perhaps, but the expectation for this patch set was that ereport callers would not have to change anything. And this aspect of the patch set was already the most invasive and least compelling part of it, so let's just drop it. Per buildfarm. Discussion: https://postgr.es/m/CA+fd4k6N8EjNvZpM8nme+y+05mz-SM8Z_BgkixzkA34R+ej0Kw@mail.gmail.com
2020-03-24Improve the internal implementation of ereport().Tom Lane
Change all the auxiliary error-reporting routines to return void, now that we no longer need to pretend they are passing something useful to errfinish(). While this probably doesn't save anything significant at the machine-code level, it allows detection of some additional types of mistakes. Pass the error location details (__FILE__, __LINE__, PG_FUNCNAME_MACRO) to errfinish not errstart. This shaves a few cycles off the case where errstart decides we're not going to emit anything. Re-implement elog() as a trivial wrapper around ereport(), removing the separate support infrastructure it used to have. Aside from getting rid of some now-surplus code, this means that elog() now really does have exactly the same semantics as ereport(), in particular that it can skip evaluation work if the message is not to be emitted. Andres Freund and Tom Lane Discussion: https://postgr.es/m/CA+fd4k6N8EjNvZpM8nme+y+05mz-SM8Z_BgkixzkA34R+ej0Kw@mail.gmail.com
2020-03-22Revert "Skip WAL for new relfilenodes, under wal_level=minimal."Noah Misch
This reverts commit cb2fd7eac285b1b0a24eeb2b8ed4456b66c5a09f. Per numerous buildfarm members, it was incompatible with parallel query, and a test case assumed LP64. Back-patch to 9.5 (all supported versions). Discussion: https://postgr.es/m/20200321224920.GB1763544@rfd.leadboat.com
2020-03-21Skip WAL for new relfilenodes, under wal_level=minimal.Noah Misch
Until now, only selected bulk operations (e.g. COPY) did this. If a given relfilenode received both a WAL-skipping COPY and a WAL-logged operation (e.g. INSERT), recovery could lose tuples from the COPY. See src/backend/access/transam/README section "Skipping WAL for New RelFileNode" for the new coding rules. Maintainers of table access methods should examine that section. To maintain data durability, just before commit, we choose between an fsync of the relfilenode and copying its contents to WAL. A new GUC, wal_skip_threshold, guides that choice. If this change slows a workload that creates small, permanent relfilenodes under wal_level=minimal, try adjusting wal_skip_threshold. Users setting a timeout on COMMIT may need to adjust that timeout, and log_min_duration_statement analysis will reflect time consumption moving to COMMIT from commands like COPY. Internally, this requires a reliable determination of whether RollbackAndReleaseCurrentSubTransaction() would unlink a relation's current relfilenode. Introduce rd_firstRelfilenodeSubid. Amend the specification of rd_createSubid such that the field is zero when a new rel has an old rd_node. Make relcache.c retain entries for certain dropped relations until end of transaction. Back-patch to 9.5 (all supported versions). This introduces a new WAL record type, XLOG_GIST_ASSIGN_LSN, without bumping XLOG_PAGE_MAGIC. As always, update standby systems before master systems. This changes sizeof(RelationData) and sizeof(IndexStmt), breaking binary compatibility for affected extensions. (The most recent commit to affect the same class of extensions was 089e4d405d0f3b94c74a2c6a54357a84a681754b.) Kyotaro Horiguchi, reviewed (in earlier, similar versions) by Robert Haas. Heikki Linnakangas and Michael Paquier implemented earlier designs that materially clarified the problem. Reviewed, in earlier designs, by Andrew Dunstan, Andres Freund, Alvaro Herrera, Tom Lane, Fujii Masao, and Simon Riggs. Reported by Martijn van Oosterhout. Discussion: https://postgr.es/m/20150702220524.GA9392@svana.org
2020-03-19Introduce "anycompatible" family of polymorphic types.Tom Lane
This patch adds the pseudo-types anycompatible, anycompatiblearray, anycompatiblenonarray, and anycompatiblerange. They work much like anyelement, anyarray, anynonarray, and anyrange respectively, except that the actual input values need not match precisely in type. Instead, if we can find a common supertype (using the same rules as for UNION/CASE type resolution), then the parser automatically promotes the input values to that type. For example, "myfunc(anycompatible, anycompatible)" can match a call with one integer and one bigint argument, with the integer automatically promoted to bigint. With anyelement in the definition, the user would have had to cast the integer explicitly. The new types also provide a second, independent set of type variables for function matching; thus with "myfunc(anyelement, anyelement, anycompatible) returns anycompatible" the first two arguments are constrained to be the same type, but the third can be some other type, and the result has the type of the third argument. The need for more than one set of type variables was foreseen back when we first invented the polymorphic types, but we never did anything about it. Pavel Stehule, revised a bit by me Discussion: https://postgr.es/m/CAFj8pRDna7VqNi8gR+Tt2Ktmz0cq5G93guc3Sbn_NVPLdXAkqA@mail.gmail.com
2020-03-17Refactor our checks for valid function and aggregate signatures.Tom Lane
pg_proc.c and pg_aggregate.c had near-duplicate copies of the logic to decide whether a function or aggregate's signature is legal. This seems like a bad thing even without the problem that the upcoming "anycompatible" patch would roughly double the complexity of that logic. Hence, refactor so that the rules are localized in new subroutines supplied by parse_coerce.c. (One could quibble about just where to add that code, but putting it beside enforce_generic_type_consistency seems not totally unreasonable.) The fact that the rules are about to change would mandate some changes in the wording of the associated error messages in any case. I ended up spelling things out in a fairly literal fashion in the errdetail messages, eg "A result of type anyelement requires at least one input of type anyelement, anyarray, anynonarray, anyenum, or anyrange." Perhaps this is overkill, but once there's more than one subgroup of polymorphic types, people might get confused by more-abstract messages. Discussion: https://postgr.es/m/24137.1584139352@sss.pgh.pa.us
2020-03-17Adjust handling of an ANYARRAY actual input for an ANYARRAY argument.Tom Lane
Ordinarily it's impossible for an actual input of a function to have declared type ANYARRAY, since we'd resolve that to a concrete array type before doing argument type resolution for the function. But an exception arises for functions applied to certain columns of pg_statistic or pg_stats, since we abuse the "anyarray" pseudotype by using it to declare those columns. So parse_coerce.c has to deal with the case. Previously we allowed an ANYARRAY actual input to match an ANYARRAY polymorphic argument, but only if no other argument or result was declared ANYELEMENT. When that logic was written, those were the only two polymorphic types, and I fear nobody thought carefully about how it ought to extend to the other ones that came along later. But actually it was wrong even then, because if a function has two ANYARRAY arguments, it should be able to expect that they have identical element types, and we'd not be able to ensure that. The correct generalization is that we can match an ANYARRAY actual input to an ANYARRAY polymorphic argument only if no other argument or result is of any polymorphic type, so that no promises are being made about element type compatibility. check_generic_type_consistency can't test that condition, but it seems better anyway to accept such matches there and then throw an error if needed in enforce_generic_type_consistency. That way we can produce a specific error message rather than an unintuitive "function does not exist" complaint. (There's some risk perhaps of getting new ambiguous-function complaints, but I think that any set of functions for which that could happen would be ambiguous against ordinary array columns as well.) While we're at it, we can improve the message that's produced in cases that the code did already object to, as shown in the regression test changes. Also, remove a similar test that got cargo-culted in for ANYRANGE; there are no catalog columns of type ANYRANGE, and I hope we never create any, so that's not needed. (It was incomplete anyway.) While here, update some comments and rearrange the code a bit in preparation for upcoming additions of more polymorphic types. In practical situations I believe this is just exchanging one error message for another, hopefully better, one. So it doesn't seem needful to back-patch, even though the mistake is ancient. Discussion: https://postgr.es/m/21569.1584314271@sss.pgh.pa.us