summaryrefslogtreecommitdiff
path: root/src/backend/utils/adt
AgeCommit message (Collapse)Author
2023-05-04In array_position()/array_positions(), beware of empty input array.Tom Lane
These functions incautiously fetched the array's first lower bound even when the array is zero-dimensional, thus fetching the word after the allocated array space. While almost always harmless, with very bad luck this could result in SIGSEGV. Fix by adding an early exit for empty input. Per bug #17920 from Alexander Lakhin. Discussion: https://postgr.es/m/17920-f7c228c627b6d02e%40postgresql.org
2023-04-24Remove duplicate lines of codeDaniel Gustafsson
Commit 6df7a9698bb accidentally included two identical prototypes for default_multirange_selectivi() and commit 086cf1458c6 added a break; statement where one was already present, thus duplicating it. While there is no bug caused by this, fix by removing the duplicated lines as they provide no value. Backpatch the fix for duplicate prototypes to v14 and the duplicate break statement fix to all supported branches to avoid backpatching hazards due to the removal. Reported-by: Anton Voloshin <a.voloshin@postgrespro.ru> Discussion: https://postgr.es/m/0e69cb60-0176-f6d0-7e15-6478b7d85724@postgrespro.ru
2023-03-26Fix oversights in array manipulation.Tom Lane
The nested-arrays code path in ExecEvalArrayExpr() used palloc to allocate the result array, whereas every other array-creating function has used palloc0 since 18c0b4ecc. This mostly works, but unused bits past the end of the nulls bitmap may end up undefined. That causes valgrind complaints with -DWRITE_READ_PARSE_PLAN_TREES, and could cause planner misbehavior as cited in 18c0b4ecc. There seems no very good reason why we should strive to avoid palloc0 in just this one case, so fix it the easy way with s/palloc/palloc0/. While looking at that I noted that we also failed to check for overflow of "nbytes" and "nitems" while summing the sizes of the sub-arrays, potentially allowing a crash due to undersized output allocation. For "nbytes", follow the policy used by other array-munging code of checking for overflow after each addition. (As elsewhere, the last addition of the array's overhead space doesn't need an extra check, since palloc itself will catch a value between 1Gb and 2Gb.) For "nitems", there's no very good reason to sum the inputs at all, since we can perfectly well use ArrayGetNItems' result instead of ignoring it. Per discussion of this bug, also remove redundant zeroing of the nulls bitmap in array_set_element and array_set_slice. Patch by Alexander Lakhin and myself, per bug #17858 from Alexander Lakhin; thanks also to Richard Guo. These bugs are a dozen years old, so back-patch to all supported branches. Discussion: https://postgr.es/m/17858-8fd287fd3663d051@postgresql.org
2023-03-16Work around spurious compiler warning in inet operatorsAndres Freund
gcc 12+ has complaints like the following: ../../../../../pgsql/src/backend/utils/adt/network.c: In function 'inetnot': ../../../../../pgsql/src/backend/utils/adt/network.c:1893:34: warning: writing 1 byte into a region of size 0 [-Wstringop-overflow=] 1893 | pdst[nb] = ~pip[nb]; | ~~~~~~~~~^~~~~~~~~~ ../../../../../pgsql/src/include/utils/inet.h:27:23: note: at offset -1 into destination object 'ipaddr' of size 16 27 | unsigned char ipaddr[16]; /* up to 128 bits of address */ | ^~~~~~ ../../../../../pgsql/src/include/utils/inet.h:27:23: note: at offset -1 into destination object 'ipaddr' of size 16 This is due to a compiler bug: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104986 It has been a year since the bug has been reported without getting fixed. As the warnings are verbose and use of gcc 12 is becoming more common, it seems worth working around the bug. Particularly because a simple reformulation of the loop condition fixes the issue and isn't any less readable. Author: Tom Lane <tgl@sss.pgh.pa.us> Author: Andres Freund <andres@anarazel.de> Discussion: https://postgr.es/m/144536.1648326206@sss.pgh.pa.us Backpatch: 11-
2023-03-14Fix corner case bug in numeric to_char() some more.Tom Lane
The band-aid applied in commit f0bedf3e4 turns out to still need some work: it made sure we didn't set Np->last_relevant too small (to the left of the decimal point), but it didn't prevent setting it too large (off the end of the partially-converted string). This could result in fetching data beyond the end of the allocated space, which with very bad luck could cause a SIGSEGV, though I don't see any hazard of interesting memory disclosure. Per bug #17839 from Thiago Nunes. The bug's pretty ancient, so back-patch to all supported versions. Discussion: https://postgr.es/m/17839-aada50db24d7b0da@postgresql.org
2023-03-13Fix JSON error reporting for many cases of erroneous string values.Tom Lane
The majority of error exit cases in json_lex_string() failed to set lex->token_terminator, causing problems for the error context reporting code: it would see token_terminator less than token_start and do something more or less nuts. In v14 and up the end result could be as bad as a crash in report_json_context(). Older versions accidentally avoided that fate; but all versions produce error context lines that are far less useful than intended, because they'd stop at the end of the prior token instead of continuing to where the actually-bad input is. To fix, invent some macros that make it less notationally painful to do the right thing. Also add documentation about what the function is actually required to do; and in >= v14, add an assertion in report_json_context about token_terminator being sufficiently far advanced. Per report from Nikolay Shaplov. Back-patch to all supported versions. Discussion: https://postgr.es/m/7332649.x5DLKWyVIX@thinkpad-pgpro
2023-03-01Avoid fetching one past the end of translate()'s "to" parameter.Tom Lane
This is usually harmless, but if you were very unlucky it could provoke a segfault due to the "to" string being right up against the end of memory. Found via valgrind testing (so we might've found it earlier, except that our regression tests lacked any exercise of translate()'s deletion feature). Fix by switching the order of the test-for-end-of-string and advance-pointer steps. While here, compute "to_ptr + tolen" just once. (Smarter compilers might figure that out for themselves, but let's just make sure.) Report and fix by Daniil Anisimov, in bug #17816. Discussion: https://postgr.es/m/17816-70f3d2764e88a108@postgresql.org
2023-02-17Print the correct aliases for DML target tables in ruleutils.Tom Lane
ruleutils.c blindly printed the user-given alias (or nothing if there hadn't been one) for the target table of INSERT/UPDATE/DELETE queries. That works a large percentage of the time, but not always: for queries appearing in WITH, it's possible that we chose a different alias to avoid conflict with outer-scope names. Since the chosen alias would be used in any Var references to the target table, this'd lead to an inconsistent printout with consequences such as dump/restore failures. The correct logic for printing (or not) a relation alias was embedded in get_from_clause_item. Factor it out to a separate function so that we don't need a jointree node to use it. (Only a limited part of that function can be reached from these new call sites, but this seems like the cleanest non-duplicative factorization.) In passing, I got rid of a redundant "\d+ rules_src" step in rules.sql. Initial report from Jonathan Katz; thanks to Vignesh C for analysis. This has been broken for a long time, so back-patch to all supported branches. Discussion: https://postgr.es/m/e947fa21-24b2-f922-375a-d4f763ef3e4b@postgresql.org Discussion: https://postgr.es/m/CALDaNm1MMntjmT_NJGp-Z=xbF02qHGAyuSHfYHias3TqQbPF2w@mail.gmail.com
2023-02-03Make int64_div_fast_to_numeric() more robust.Dean Rasheed
The prior coding of int64_div_fast_to_numeric() had a number of bugs that would cause it to fail under different circumstances, such as with log10val2 <= 0, or log10val2 a multiple of 4, or in the "slow" numeric path with log10val2 >= 10. None of those could be triggered by any of our current code, which only uses log10val2 = 3 or 6. However, they made it a hazard for any future code that might use it. Also, since this is exported by numeric.c, users writing their own C code might choose to use it. Therefore fix, and back-patch to v14, where it was introduced. Dean Rasheed, reviewed by Tom Lane. Discussion: https://postgr.es/m/CAEZATCW8gXgW0tgPxPgHDPhVX71%2BSWFRkhnXy%2BTfGDsKLepu2g%40mail.gmail.com
2023-01-12Fix jsonpath existense checking of missing variablesAlexander Korotkov
The current jsonpath code assumes that the referenced variable always exists. It could only throw an error at the value valuation time. At the same time existence checking assumes variable is present without valuation, and error suppression doesn't work for missing variables. This commit makes existense checking trigger an error for missing variables. This makes the overall behavior consistent. Backpatch to 12 where jsonpath was introduced. Reported-by: David G. Johnston Discussion: https://postgr.es/m/CAKFQuwbeytffJkVnEqDyLZ%3DrQsznoTh1OgDoOF3VmOMkxcTMjA%40mail.gmail.com Author: Alexander Korotkov, David G. Johnston Backpatch-through: 12
2023-01-03Fix typos in comments, code and documentationMichael Paquier
While on it, newlines are removed from the end of two elog() strings. The others are simple grammar mistakes. One comment in pg_upgrade referred incorrectly to sequences since a7e5457. Author: Justin Pryzby Discussion: https://postgr.es/m/20221230231257.GI1153@telsasoft.com Backpatch-through: 11
2022-12-12Fix jsonb subscripting to cope with toasted subscript values.Tom Lane
jsonb_get_element() was incautious enough to use VARDATA() and VARSIZE() directly on an arbitrary text Datum. That of course fails if the Datum is short-header, compressed, or out-of-line. The typical result would be failing to match any element of a jsonb object, though matching the wrong one seems possible as well. setPathObject() was slightly brighter, in that it used VARDATA_ANY and VARSIZE_ANY_EXHDR, but that only kept it out of trouble for short-header Datums. push_path() had the same issue. This could result in faulty subscripted insertions, though keys long enough to cause a problem are likely rare in the wild. Having seen these, I looked around for unsafe usages in the rest of the adt/json* files. There are a couple of places where it's not immediately obvious that the Datum can't be compressed or out-of-line, so I added pg_detoast_datum_packed() to cope if it is. Also, remove some other usages of VARDATA/VARSIZE on Datums we just extracted from a text array. Those aren't actively broken, but they will become so if we ever start allowing short-header array elements, which does not seem like a terribly unreasonable thing to do. In any case they are not great coding examples, and they could also do with comments pointing out that we're assuming we don't need pg_detoast_datum_packed. Per report from exe-dealer@yandex.ru. Patch by me, but thanks to David Johnston for initial investigation. Back-patch to v14 where jsonb subscripting was introduced. Discussion: https://postgr.es/m/205321670615953@mail.yandex.ru
2022-12-02Fix psql's \sf and \ef for new-style SQL functions.Tom Lane
Some options of these commands need to be able to identify the start of the function body within the output of pg_get_functiondef(). It used to be that that always began with "AS", but since the introduction of new-style SQL functions, it might also start with "BEGIN" or "RETURN". Fix that on the psql side, and add some regression tests. Noted by me awhile ago, but I didn't do anything about it. Thanks to David Johnston for a nag. Discussion: https://postgr.es/m/AM9PR01MB8268D5CDABDF044EE9F42173FE8C9@AM9PR01MB8268.eurprd01.prod.exchangelabs.com
2022-12-01Fix memory leak for hashing with nondeterministic collations.Jeff Davis
Backpatch through 12, where nondeterministic collations were introduced (5e1963fb76). Backpatch-through: 12
2022-12-01Fix under-parenthesized display of AT TIME ZONE constructs.Tom Lane
In commit 40c24bfef, I forgot to use get_rule_expr_paren() for the arguments of AT TIME ZONE, resulting in possibly not printing parens for expressions that need it. But get_rule_expr_paren() wouldn't have gotten it right anyway, because isSimpleNode() hadn't been taught that COERCE_SQL_SYNTAX parent nodes don't guarantee sufficient parentheses. Improve all that. Also use this methodology for F_IS_NORMALIZED, so that we don't print useless parens for that. In passing, remove a comment that was obsoleted later. Per report from Duncan Sands. Back-patch to v14 where this code came in. (Before that, we didn't try to print AT TIME ZONE that way, so there was no bug just ugliness.) Discussion: https://postgr.es/m/f41566aa-a057-6628-4b7c-b48770ecb84a@deepbluecap.com
2022-11-22YA attempt at taming worst-case behavior of get_actual_variable_range.Tom Lane
We've made multiple attempts at preventing get_actual_variable_range from taking an unreasonable amount of time (3ca930fc3, fccebe421). But there's still an issue for the very first planning attempt after deletion of a large number of extremal-valued tuples. While that planning attempt will set "killed" bits on the tuples it visits and thereby reduce effort for next time, there's still a lot of work it has to do to visit the heap and then set those bits. It's (usually?) not worth it to do that much work at plan time to have a slightly better estimate, especially in a context like this where the table contents are known to be mutating rapidly. Therefore, let's bound the amount of work to be done by giving up after we've visited 100 heap pages. Giving up just means we'll fall back on the extremal value recorded in pg_statistic, so it shouldn't mean that planner estimates suddenly become worthless. Note that this means we'll still gradually whittle down the problem by setting a few more index "killed" bits in each planning attempt; so eventually we'll reach a good state (barring further deletions), even in the absence of VACUUM. Simon Riggs, per a complaint from Jakub Wartak (with cosmetic adjustments by me). Back-patch to all supported branches. Discussion: https://postgr.es/m/CAKZiRmznOwi0oaV=4PHOCM4ygcH4MgSvt8=5cu_vNCfc8FSUug@mail.gmail.com
2022-11-21Add comments and a missing CHECK_FOR_INTERRUPTS in ts_headline.Tom Lane
I just spent an annoying amount of time reverse-engineering the 100%-undocumented API between ts_headline and the text search parser's prsheadline function. Add some commentary about that while it's fresh in mind. Also remove some unused macros in wparser_def.c. While at it, I noticed that when commit 78e73e875 added a CHECK_FOR_INTERRUPTS call in TS_execute_recurse, it missed doing so in the parallel function TS_phrase_execute, which surely needs one just as much. Back-patch because of the missing CHECK_FOR_INTERRUPTS. Might as well back-patch the rest of this too.
2022-10-16Fix EXPLAIN of SEARCH BREADTH FIRST with a constant initial value.Tom Lane
If the non-recursive term of a SEARCH BREADTH FIRST recursive query has only constants in its target list, the planner will fold the starting RowExpr added by rewrite into a simple Const of type RECORD. The executor doesn't have any problem with that --- but EXPLAIN VERBOSE will encounter the Const as the ultimate source of truth about what the field names of the SET column are, and it didn't know what to do with that. Fortunately, we can pull the identifying typmod out of the Const, in much the same way that record_out would. For reasons that remain a bit obscure to me, this only fails with SEARCH BREADTH FIRST, not SEARCH DEPTH FIRST or CYCLE. But I added regression test cases for both of those options too, just to make sure we don't break it in future. Per bug #17644 from Matthijs van der Vleuten. Back-patch to v14 where these constructs were added. Discussion: https://postgr.es/m/17644-3bd1f3036d6d7a16@postgresql.org
2022-09-28Change some errdetail() to errdetail_internal()Alvaro Herrera
This prevents marking the argument string for translation for gettext, and it also prevents the given string (which is already translated) from being translated at runtime. Also, mark the strings used as arguments to check_rolespec_name for translation. Backpatch all the way back as appropriate. None of this is caught by any tests (necessarily so), so I verified it manually.
2022-09-20Suppress variable-set-but-not-used warnings from clang 15.Tom Lane
clang 15+ will issue a set-but-not-used warning when the only use of a variable is in autoincrements (e.g., "foo++;"). That's perfectly sensible, but it detects a few more cases that we'd not noticed before. Silence the warnings with our usual methods, such as PG_USED_FOR_ASSERTS_ONLY, or in one case by actually removing a useless variable. One thing that we can't nicely get rid of is that with %pure-parser, Bison emits "yynerrs" as a local variable that falls foul of this warning. To silence those, I inserted "(void) yynerrs;" in the top-level productions of affected grammars. Per recently-established project policy, this is a candidate for back-patching into out-of-support branches: it suppresses annoying compiler warnings but changes no behavior. Hence, back-patch to 9.5, which is as far as these patches go without issues. (A preliminary check shows that the prior branches need some other set-but-not-used cleanups too, so I'll leave them for another day.) Discussion: https://postgr.es/m/514615.1663615243@sss.pgh.pa.us
2022-09-12Fix NaN comparison in circle_same testDaniel Gustafsson
Commit c4c340088 changed geometric operators to use float4 and float8 functions, and handle NaN's in a better way. The circle sameness test had a typo in the code which resulted in all comparisons with the left circle having a NaN radius considered same. postgres=# select '<(0,0),NaN>'::circle ~= '<(0,0),1>'::circle; ?column? ---------- t (1 row) This fixes the sameness test to consider the radius of both the left and right circle. Backpatch to v12 where this was introduced. Author: Ranier Vilela <ranier.vf@gmail.com> Discussion: https://postgr.es/m/CAEudQAo8dK=yctg2ZzjJuzV4zgOPBxRU5+Kb+yatFiddtQk6Rw@mail.gmail.com Backpatch-through: v12
2022-08-24Defend against stack overrun in a few more places.Tom Lane
SplitToVariants() in the ispell code, lseg_inside_poly() in geo_ops.c, and regex_selectivity_sub() in selectivity estimation could recurse until stack overflow; fix by adding check_stack_depth() calls. So could next() in the regex compiler, but that case is better fixed by converting its tail recursion to a loop. (We probably get better code that way too, since next() can now be inlined into its sole caller.) There remains a reachable stack overrun in the Turkish stemmer, but we'll need some advice from the Snowball people about how to fix that. Per report from Egor Chindyaskin and Alexander Lakhin. These mistakes are old, so back-patch to all supported branches. Richard Guo and Tom Lane Discussion: https://postgr.es/m/1661334672.728714027@f473.i.mail.ru
2022-08-14Preserve memory context of VarStringSortSupport buffers.Tom Lane
When enlarging the work buffers of a VarStringSortSupport object, varstrfastcmp_locale was careful to keep them in the ssup_cxt memory context; but varstr_abbrev_convert just used palloc(). The latter creates a hazard that the buffers could be freed out from under the VarStringSortSupport object, resulting in stomping on whatever gets allocated in that memory later. In practice, because we only use this code for ICU collations (cf. 3df9c374e), the problem is confined to use of ICU collations. I believe it may have been unreachable before the introduction of incremental sort, too, as traditional sorting usually just uses one context for the duration of the sort. We could fix this by making the broken stanzas in varstr_abbrev_convert match the non-broken ones in varstrfastcmp_locale. However, it seems like a better idea to dodge the issue altogether by replacing the pfree-and-allocate-anew coding with repalloc, which automatically preserves the chunk's memory context. This fix does add a few cycles because repalloc will copy the chunk's content, which the existing coding assumes is useless. However, we don't expect that these buffer enlargement operations are performance-critical. Besides that, it's far from obvious that copying the buffer contents isn't required, since these stanzas make no effort to mark the buffers invalid by resetting last_returned, cache_blob, etc. That seems to be safe upon examination, but it's fragile and could easily get broken in future, which wouldn't get revealed in testing with short-to-moderate-size strings. Per bug #17584 from James Inform. Whether or not the issue is reachable in the older branches, this code has been broken on its own terms from its introduction, so patch all the way back. Discussion: https://postgr.es/m/17584-95c79b4a7d771f44@postgresql.org
2022-07-31Fix trim_array() for zero-dimensional array argument.Tom Lane
The code tried to access ARR_DIMS(v)[0] and ARR_LBOUND(v)[0] whether or not those values exist. This made the range check on the "n" argument unstable --- it might or might not fail, and if it did it would report garbage for the allowed upper limit. These bogus accesses would probably annoy Valgrind, and if you were very unlucky even lead to SIGSEGV. Report and fix by Martin Kalcher. Back-patch to v14 where this function was added. Discussion: https://postgr.es/m/baaeb413-b8a8-4656-5757-ef347e5ec11f@aboutsource.net
2022-07-27Allow "in place" tablespaces.Alvaro Herrera
This is a backpatch to branches 10-14 of the following commits: 7170f2159fb2 Allow "in place" tablespaces. c6f2f01611d4 Fix pg_basebackup with in-place tablespaces. f6f0db4d6240 Fix pg_tablespace_location() with in-place tablespaces 7a7cd84893e0 doc: Remove mention to in-place tablespaces for pg_tablespace_location() 5344723755bd Remove unnecessary Windows-specific basebackup code. In-place tablespaces were introduced as a testing helper mechanism, but they are going to be used for a bugfix in WAL replay to be backpatched to all stable branches. I (Álvaro) had to adjust some code to account for lack of get_dirent_type() in branches prior to 14. Author: Thomas Munro <thomas.munro@gmail.com> Author: Michaël Paquier <michael@paquier.xyz> Author: Álvaro Herrera <alvherre@alvh.no-ip.org> Discussion: https://postgr.es/m/20220722081858.omhn2in5zt3g4nek@alvherre.pgsql
2022-07-21Fix ruleutils issues with dropped cols in functions-returning-composite.Tom Lane
Due to lack of concern for the case in the dependency code, it's possible to drop a column of a composite type even though stored queries have references to the dropped column via functions-in-FROM that return the composite type. There are "soft" references, namely FROM-clause aliases for such columns, and "hard" references, that is actual Vars referring to them. The right fix for hard references is to add dependencies preventing the drop; something we've known for many years and not done (and this commit still doesn't address it). A "soft" reference shouldn't prevent a drop though. We've been around on this before (cf. 9b35ddce9, 2c4debbd0), but nobody had noticed that the current behavior can result in dump/reload failures, because ruleutils.c can print more column aliases than the underlying composite type now has. So we need to rejigger the column-alias-handling code to treat such columns as dropped and not print aliases for them. Rather than writing new code for this, I used expandRTE() which already knows how to figure out which function result columns are dropped. I'd initially thought maybe we could use expandRTE() in all cases, but that fails for EXPLAIN's purposes, because the planner strips a lot of RTE infrastructure that expandRTE() needs. So this patch just uses it for unplanned function RTEs and otherwise does things the old way. If there is a hard reference (Var), then removing the column alias causes us to fail to print the Var, since there's no longer a name to print. Failing seems less desirable than printing a made-up name, so I made it print "?dropped?column?" instead. Per report from Timo Stolz. Back-patch to all supported branches. Discussion: https://postgr.es/m/5c91267e-3b6d-5795-189c-d15a55d61dbb@nullachtvierzehn.de
2022-07-17Fix omissions in support for the "regcollation" type.Tom Lane
The patch that added regcollation doesn't seem to have been too thorough about supporting it everywhere that other reg* types are supported. Fix that. (The find_expr_references omission is moderately serious, since it could result in missing expression dependencies. The others are less exciting.) Noted while fixing bug #17483. Back-patch to v13 where regcollation was added. Discussion: https://postgr.es/m/1423433.1652722406@sss.pgh.pa.us
2022-07-12Invent qsort_interruptible().Tom Lane
Justin Pryzby reported that some scenarios could cause gathering of extended statistics to spend many seconds in an un-cancelable qsort() operation. To fix, invent qsort_interruptible(), which is just like qsort_arg() except that it will also do CHECK_FOR_INTERRUPTS every so often. This bloats the backend by a couple of kB, which seems like a good investment. (We considered just enabling CHECK_FOR_INTERRUPTS in the existing qsort and qsort_arg functions, but there are some callers for which that'd demonstrably be unsafe. Opt-in seems like a better way.) For now, just apply qsort_interruptible() in statistics collection. There's probably more places where it could be useful, but we can always change other call sites as we find problems. Back-patch to v14. Before that we didn't have extended stats on expressions, so that the problem was less severe. Also, this patch depends on the sort_template infrastructure introduced in v14. Tom Lane and Justin Pryzby Discussion: https://postgr.es/m/20220509000108.GQ28830@telsasoft.com
2022-07-03Remove %error-verbose directive from jsonpath parserAndrew Dunstan
None of the other bison parsers contains this directive, and it gives rise to some unfortunate and impenetrable messages, so just remove it. Backpatch to release 12, where it was introduced. Per gripe from Erik Rijkers Discussion: https://postgr.es/m/ba069ce2-a98f-dc70-dc17-2ccf2a9bf7c7@xs4all.nl
2022-06-27Fix visibility check when XID is committed in CLOG but not in procarray.Heikki Linnakangas
TransactionIdIsInProgress had a fast path to return 'false' if the single-item CLOG cache said that the transaction was known to be committed. However, that was wrong, because a transaction is first marked as committed in the CLOG but doesn't become visible to others until it has removed its XID from the proc array. That could lead to an error: ERROR: t_xmin is uncommitted in tuple to be updated or for an UPDATE to go ahead without blocking, before the previous UPDATE on the same row was made visible. The window is usually very short, but synchronous replication makes it much wider, because the wait for synchronous replica happens in that window. Another thing that makes it hard to hit is that it's hard to get such a commit-in-progress transaction into the single item CLOG cache. Normally, if you call TransactionIdIsInProgress on such a transaction, it determines that the XID is in progress without checking the CLOG and without populating the cache. One way to prime the cache is to explicitly call pg_xact_status() on the XID. Another way is to use a lot of subtransactions, so that the subxid cache in the proc array is overflown, making TransactionIdIsInProgress rely on pg_subtrans and CLOG checks. This has been broken ever since it was introduced in 2008, but the race condition is very hard to hit, especially without synchronous replication. There were a couple of reports of the error starting from summer 2021, but no one was able to find the root cause then. TransactionIdIsKnownCompleted() is now unused. In 'master', remove it, but I left it in place in backbranches in case it's used by extensions. Also change pg_xact_status() to check TransactionIdIsInProgress(). Previously, it only checked the CLOG, and returned "committed" before the transaction was actually made visible to other queries. Note that this also means that you cannot use pg_xact_status() to reproduce the bug anymore, even if the code wasn't fixed. Report and analysis by Konstantin Knizhnik. Patch by Simon Riggs, with the pg_xact_status() change added by me. Author: Simon Riggs Reviewed-by: Andres Freund Discussion: https://www.postgresql.org/message-id/flat/4da7913d-398c-e2ad-d777-f752cf7f0bbb%40garret.ru
2022-05-21Show 'AS "?column?"' explicitly when it's important.Tom Lane
ruleutils.c was coded to suppress the AS label for a SELECT output expression if the column name is "?column?", which is the parser's fallback if it can't think of something better. This is fine, and avoids ugly clutter, so long as (1) nothing further up in the parse tree relies on that column name or (2) the same fallback would be assigned when the rule or view definition is reloaded. Unfortunately (2) is far from certain, both because ruleutils.c might print the expression in a different form from how it was originally written and because FigureColname's rules might change in future releases. So we shouldn't rely on that. Detecting exactly whether there is any outer-level use of a SELECT column name would be rather expensive. This patch takes the simpler approach of just passing down a flag indicating whether there *could* be any outer use; for example, the output column names of a SubLink are not referenceable, and we also do not care about the names exposed by the right-hand side of a setop. This is sufficient to suppress unwanted clutter in all but one case in the regression tests. That seems like reasonable evidence that it won't be too much in users' faces, while still fixing the cases we need to fix. Per bug #17486 from Nicolas Lutic. This issue is ancient, so back-patch to all supported branches. Discussion: https://postgr.es/m/17486-1ad6fd786728b8af@postgresql.org
2022-05-09Revert "Disallow infinite endpoints in generate_series() for timestamps."Tom Lane
This reverts commit eafdf9de06e9b60168f5e47cedcfceecdc6d4b5f and its back-branch counterparts. Corey Huinker pointed out that we'd discussed this exact change back in 2016 and rejected it, on the grounds that there's at least one usage pattern with LIMIT where an infinite endpoint can usefully be used. Perhaps that argument needs to be re-litigated, but there's no time left before our back-branch releases. To keep our options open, restore the status quo ante; if we do end up deciding to change things, waiting one more quarter won't hurt anything. Rather than just doing a straight revert, I added a new test case demonstrating the usage with LIMIT. That'll at least remind us of the issue if we forget again. Discussion: https://postgr.es/m/3603504.1652068977@sss.pgh.pa.us Discussion: https://postgr.es/m/CADkLM=dzw0Pvdqp5yWKxMd+VmNkAMhG=4ku7GnCZxebWnzmz3Q@mail.gmail.com
2022-04-20Disallow infinite endpoints in generate_series() for timestamps.Tom Lane
Such cases will lead to infinite loops, so they're of no practical value. The numeric variant of generate_series() already threw error for this, so borrow its message wording. Per report from Richard Wesley. Back-patch to all supported branches. Discussion: https://postgr.es/m/91B44E7B-68D5-448F-95C8-B4B3B0F5DEAF@duckdblabs.com
2022-04-19Fix extract epoch from interval calculationPeter Eisentraut
The new numeric code for extract epoch from interval accidentally truncated the DAYS_PER_YEAR value to an integer, leading to results that mismatched the floating-point interval_part calculations. The commit a2da77cdb4661826482ebf2ddba1f953bc74afe4 that introduced this actually contains the regression test change that this reverts. I suppose this was missed at the time. Reported-by: Joseph Koshakow <koshy44@gmail.com> Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us> Discussion: https://www.postgresql.org/message-id/flat/CAAvxfHd5n%3D13NYA2q_tUq%3D3%3DSuWU-CufmTf-Ozj%3DfrEgt7pXwQ%40mail.gmail.com
2022-03-27Fix NULL input behaviour of pg_stat_get_replication_slot().Andres Freund
pg_stat_get_replication_slot() accidentally was marked as non-strict, crashing when called with NULL input. As it's already released, introduce an explicit NULL check in 14, fix the catalog in HEAD. Bumps catversion in HEAD. Discussion: https://postgr.es/m/20220326212432.s5n2maw6kugnpyxw@alap3.anarazel.de Backpatch: 14-, where replication slot stats were introduced
2022-03-21Fix assorted missing logic for GroupingFunc nodes.Tom Lane
The planner needs to treat GroupingFunc like Aggref for many purposes, in particular with respect to processing of the argument expressions, which are not to be evaluated at runtime. A few places hadn't gotten that memo, notably including subselect.c's processing of outer-level aggregates. This resulted in assertion failures or wrong plans for cases in which a GROUPING() construct references an outer aggregation level. Also fix missing special cases for GroupingFunc in cost_qual_eval (resulting in wrong cost estimates for GROUPING(), although it's not clear that that would affect plan shapes in practice) and in ruleutils.c (resulting in excess parentheses in pretty-print mode). Per bug #17088 from Yaoguang Chen. Back-patch to all supported branches. Richard Guo, Tom Lane Discussion: https://postgr.es/m/17088-e33882b387de7f5c@postgresql.org
2022-03-18Fix incorrect xmlschema output for types timetz and timestamptz.Tom Lane
The output of table_to_xmlschema() and allied functions includes a regex describing valid values for these types ... but the regex was itself invalid, as it failed to escape a literal "+" sign. Report and fix by Renan Soares Lopes. Back-patch to all supported branches. Discussion: https://postgr.es/m/7f6fabaa-3f8f-49ab-89ca-59fbfe633105@me.com
2022-03-03Clean up assorted failures under clang's -fsanitize=undefined checks.Tom Lane
Most of these are cases where we could call memcpy() or other libc functions with a NULL pointer and a zero count, which is forbidden by POSIX even though every production version of libc allows it. We've fixed such things before in a piecemeal way, but apparently never made an effort to try to get them all. I don't claim that this patch does so either, but it gets every failure I observe in check-world, using clang 12.0.1 on current RHEL8. numeric.c has a different issue that the sanitizer doesn't like: "ln(-1.0)" will compute log10(0) and then try to assign the resulting -Inf to an integer variable. We don't actually use the result in such a case, so there's no live bug. Back-patch to all supported branches, with the idea that we might start running a buildfarm member that tests this case. This includes back-patching c1132aae3 (Check the size in COPY_POINTER_FIELD), which previously silenced some of these issues in copyfuncs.c. Discussion: https://postgr.es/m/CALNJ-vT9r0DSsAOw9OXVJFxLENoVS_68kJ5x0p44atoYH+H4dg@mail.gmail.com
2022-01-27Fix ordering of XIDs in ProcArrayApplyRecoveryInfoTomas Vondra
Commit 8431e296ea reworked ProcArrayApplyRecoveryInfo to sort XIDs before adding them to KnownAssignedXids. But the XIDs are sorted using xidComparator, which compares the XIDs simply as uint32 values, not logically. KnownAssignedXidsAdd() however expects XIDs in logical order, and calls TransactionIdFollowsOrEquals() to enforce that. If there are XIDs for which the two orderings disagree, an error is raised and the recovery fails/restarts. Hitting this issue is fairly easy - you just need two transactions, one started before the 4B limit (e.g. XID 4294967290), the other sometime after it (e.g. XID 1000). Logically (4294967290 <= 1000) but when compared using xidComparator we try to add them in the opposite order. Which makes KnownAssignedXidsAdd() fail with an error like this: ERROR: out-of-order XID insertion in KnownAssignedXids This only happens during replica startup, while processing RUNNING_XACTS records to build the snapshot. Once we reach STANDBY_SNAPSHOT_READY, we skip these records. So this does not affect already running replicas, but if you restart (or create) a replica while there are transactions with XIDs for which the two orderings disagree, you may hit this. Long-running transactions and frequent replica restarts increase the likelihood of hitting this issue. Once the replica gets into this state, it can't be started (even if the old transactions are terminated). Fixed by sorting the XIDs logically - this is fine because we're dealing with normal XIDs (because it's XIDs assigned to backends) and from the same wraparound epoch (otherwise the backends could not be running at the same time on the primary node). So there are no problems with the triangle inequality, which is why xidComparator compares raw values. Investigation and root cause analysis by Abhijit Menon-Sen. Patch by me. This issue is present in all releases since 9.4, however releases up to 9.6 are EOL already so backpatch to 10 only. Reviewed-by: Abhijit Menon-Sen Reviewed-by: Alvaro Herrera Backpatch-through: 10 Discussion: https://postgr.es/m/36b8a501-5d73-277c-4972-f58a4dce088a%40enterprisedb.com
2022-01-15Build inherited extended stats on partitioned tablesTomas Vondra
Commit 859b3003de disabled building of extended stats for inheritance trees, to prevent updating the same catalog row twice. While that resolved the issue, it also means there are no extended stats for declaratively partitioned tables, because there are no data in the non-leaf relations. That also means declaratively partitioned tables were not affected by the issue 859b3003de addressed, which means this is a regression affecting queries that calculate estimates for the whole inheritance tree as a whole (which includes e.g. GROUP BY queries). But because partitioned tables are empty, we can invert the condition and build statistics only for the case with inheritance, without losing anything. And we can consider them when calculating estimates. It may be necessary to run ANALYZE on partitioned tables, to collect proper statistics. For declarative partitioning there should no prior statistics, and it might take time before autoanalyze is triggered. For tables partitioned by inheritance the statistics may include data from child relations (if built 859b3003de), contradicting the current code. Report and patch by Justin Pryzby, minor fixes and cleanup by me. Backpatch all the way back to PostgreSQL 10, where extended statistics were introduced (same as 859b3003de). Author: Justin Pryzby Reported-by: Justin Pryzby Backpatch-through: 10 Discussion: https://postgr.es/m/20210923212624.GI831%40telsasoft.com
2022-01-15Ignore extended statistics for inheritance treesTomas Vondra
Since commit 859b3003de we only build extended statistics for individual relations, ignoring the child relations. This resolved the issue with updating catalog tuple twice, but we still tried to use the statistics when calculating estimates for the whole inheritance tree. When the relations contain very distinct data, it may produce bogus estimates. This is roughly the same issue 427c6b5b9 addressed ~15 years ago, and we fix it the same way - by ignoring extended statistics when calculating estimates for the inheritance tree as a whole. We still consider extended statistics when calculating estimates for individual child relations, of course. This may result in plan changes due to different estimates, but if the old statistics were not describing the inheritance tree particularly well it's quite likely the new plans is actually better. Report and patch by Justin Pryzby, minor fixes and cleanup by me. Backpatch all the way back to PostgreSQL 10, where extended statistics were introduced (same as 859b3003de). Author: Justin Pryzby Reported-by: Justin Pryzby Backpatch-through: 10 Discussion: https://postgr.es/m/20210923212624.GI831%40telsasoft.com
2022-01-14Revert error handling improvements for cryptohashesMichael Paquier
This reverts commits ab27df2, af8d530 and 3a0cced, that introduced pg_cryptohash_error(). In order to make the core code able to pass down the new error types that this introduced, some of the MD5-related routines had to be reworked, causing an ABI breakage, but we found that some external extensions rely on them. Maintaining compatibility outweights the error report benefits, so just revert the change in v14. Reported-by: Laurenz Albe Discussion: https://postgr.es/m/9f0c0a96d28cf14fc87296bbe67061c14eb53ae8.camel@cybertec.at
2022-01-13Fix ruleutils.c's dumping of whole-row Vars in more contexts.Tom Lane
Commit 7745bc352 intended to ensure that whole-row Vars would be printed with "::type" decoration in all contexts where plain "var.*" notation would result in star-expansion, notably in ROW() and VALUES() constructs. However, it missed the case of INSERT with a single-row VALUES, as reported by Timur Khanjanov. Nosing around ruleutils.c, I found a second oversight: the code for RowCompareExpr generates ROW() notation without benefit of an actual RowExpr, and naturally it wasn't in sync :-(. (The code for FieldStore also does this, but we don't expect that to generate strictly parsable SQL anyway, so I left it alone.) Back-patch to all supported branches. Discussion: https://postgr.es/m/efaba6f9-4190-56be-8ff2-7a1674f9194f@intrans.baku.az
2022-01-11Improve error handling of cryptohash computationsMichael Paquier
The existing cryptohash facility was causing problems in some code paths related to MD5 (frontend and backend) that relied on the fact that the only type of error that could happen would be an OOM, as the MD5 implementation used in PostgreSQL ~13 (the in-core implementation is used when compiling with or without OpenSSL in those older versions), could fail only under this circumstance. The new cryptohash facilities can fail for reasons other than OOMs, like attempting MD5 when FIPS is enabled (upstream OpenSSL allows that up to 1.0.2, Fedora and Photon patch OpenSSL 1.1.1 to allow that), so this would cause incorrect reports to show up. This commit extends the cryptohash APIs so as callers of those routines can fetch more context when an error happens, by using a new routine called pg_cryptohash_error(). The error states are stored within each implementation's internal context data, so as it is possible to extend the logic depending on what's suited for an implementation. The default implementation requires few error states, but OpenSSL could report various issues depending on its internal state so more is needed in cryptohash_openssl.c, and the code is shaped so as we are always able to grab the necessary information. The core code is changed to adapt to the new error routine, painting more "const" across the call stack where the static errors are stored, particularly in authentication code paths on variables that provide log details. This way, any future changes would warn if attempting to free these strings. The MD5 authentication code was also a bit blurry about the handling of "logdetail" (LOG sent to the postmaster), so improve the comments related that, while on it. The origin of the problem is 87ae969, that introduced the centralized cryptohash facility. Extra changes are done for pgcrypto in v14 for the non-OpenSSL code path to cope with the improvements done by this commit. Reported-by: Michael Mühlbeyer Author: Michael Paquier Reviewed-by: Tom Lane Discussion: https://postgr.es/m/89B7F072-5BBE-4C92-903E-D83E865D9367@trivadis.com Backpatch-through: 14
2021-12-13Fix alignment in multirange_get_range() functionAlexander Korotkov
The multirange_get_range() function fails when two boundaries of the same range have different alignments. Fix that by adding proper pointer alignment. Reported-by: Alexander Lakhin Discussion: https://postgr.es/m/17300-dced2d01ddeb1f2f%40postgresql.org Backpatch-through: 14
2021-11-24Allow Memoize to operate in binary comparison modeDavid Rowley
Memoize would always use the hash equality operator for the cache key types to determine if the current set of parameters were the same as some previously cached set. Certain types such as floating points where -0.0 and +0.0 differ in their binary representation but are classed as equal by the hash equality operator may cause problems as unless the join uses the same operator it's possible that whichever join operator is being used would be able to distinguish the two values. In which case we may accidentally return in the incorrect rows out of the cache. To fix this here we add a binary mode to Memoize to allow it to the current set of parameters to previously cached values by comparing bit-by-bit rather than logically using the hash equality operator. This binary mode is always used for LATERAL joins and it's used for normal joins when any of the join operators are not hashable. Reported-by: Tom Lane Author: David Rowley Discussion: https://postgr.es/m/3004308.1632952496@sss.pgh.pa.us Backpatch-through: 14, where Memoize was added
2021-11-17Fix display of SQL-standard function's arguments in INSERT/SELECT.Tom Lane
If a SQL-standard function body contains an INSERT ... SELECT statement, any function parameters referenced within the SELECT were always printed in $N style, rather than using the parameter name if any. While not strictly incorrect, this wasn't the intention, and it's inconsistent with the way that such parameters would be printed in any other kind of statement. The cause is that the recursion to get_query_def from get_insert_query_def neglected to pass down the context->namespaces list, passing constant NIL instead. This is a very ancient oversight, but AFAICT it had no visible consequences before commit e717a9a18 added an outermost namespace with function parameters. We don't allow INSERT ... SELECT as a sub-query, except in a top-level WITH clause, where it couldn't contain any outer references that might need to access upper namespaces. So although that's arguably a bug, I don't see any point in changing it before v14. In passing, harden the code added to get_parameter by e717a9a18 so that it won't crash if a PARAM_EXTERN Param appears in an unexpected place. Per report from Erki Eessaar. Code fix by me, regression test case by Masahiko Sawada. Discussion: https://postgr.es/m/AM9PR01MB8268347BED344848555167FAFE949@AM9PR01MB8268.eurprd01.prod.exchangelabs.com
2021-11-12Fix memory overrun when querying pg_stat_slruMichael Paquier
pg_stat_get_slru() in pgstatfuncs.c would point to one element after the end of the array PgStat_SLRUStats when finishing to scan its entries. This had no direct consequences as no data from the extra memory area was read, but static analyzers would rightfully complain here. So let's be clean. While on it, this adds one regression test in the area reserved for system views. Reported-by: Alexander Kozhemyakin, via AddressSanitizer Author: Kyotaro Horiguchi Discussion: https://postgr.es/m/17280-37da556e86032070@postgresql.org Backpatch-through: 13
2021-10-11Fix EXPLAIN of SEARCH BREADTH FIRST queries some more.Tom Lane
Commit 3f50b8263 had an oversight: formerly, to deparse expressions attached to a plan node, it was only necessary to update the deparse_namespace ancestors list alongside calling set_deparse_plan. Now it's necessary to update the ancestors list *first*, because set_deparse_plan consults it, and one call site got that wrong. This error was masked in most cases because explain.c uses just one List object for the ancestors list, updating it in-place as the plan is scanned, so that we accidentally had the right List assigned to dpns->ancestors before it was needed. It would fail only if a WorkTableScan node were the first one that we tried to deparse a subexpression of. Per report from Markus Winand. Like the previous patch, back-patch to v14. Discussion: https://postgr.es/m/648B0505-AA57-42C2-A2DA-E551DE46FA15@winand.at
2021-10-06Fix corner-case loss of precision in numeric_power().Dean Rasheed
This fixes a loss of precision that occurs when the first input is very close to 1, so that its logarithm is very small. Formerly, during the initial low-precision calculation to estimate the result weight, the logarithm was computed to a local rscale that was capped to NUMERIC_MAX_DISPLAY_SCALE (1000). However, the base may be as close as 1e-16383 to 1, hence its logarithm may be as small as 1e-16383, and so the local rscale needs to be allowed to exceed 16383, otherwise all precision is lost, leading to a poor choice of rscale for the full-precision calculation. Fix this by removing the cap on the local rscale during the initial low-precision calculation, as we already do in the full-precision calculation. This doesn't change the fact that the initial calculation is a low-precision approximation, computing the logarithm to around 8 significant digits, which is very fast, especially when the base is very close to 1. Patch by me, reviewed by Alvaro Herrera. Discussion: https://postgr.es/m/CAEZATCV-Ceu%2BHpRMf416yUe4KKFv%3DtdgXQAe5-7S9tD%3D5E-T1g%40mail.gmail.com