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* Fix display of SQL-standard function's arguments in INSERT/SELECT.Tom Lane2021-11-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | 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
* Fix memory overrun when querying pg_stat_slruMichael Paquier2021-11-12
| | | | | | | | | | | | | | | | 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
* Disallow making an empty lexeme via array_to_tsvector().Tom Lane2021-11-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | The tsvector data type has always forbidden lexemes to be empty. However, array_to_tsvector() didn't get that memo, and would allow an empty-string array element to become an empty lexeme. This could result in dump/restore failures later, not to mention whatever semantic issues might be behind the original prohibition. However, other functions that take a plain text input directly as a lexeme value do not need a similar restriction, because they only match the string against existing tsvector entries. In particular it'd be a bad idea to make ts_delete() reject empty strings, since that is the most convenient way to clean up any bad data that might have gotten into a tsvector column via this bug. Reflecting on that, let's also remove the prohibition against NULL array elements in tsvector_delete_arr and tsvector_setweight_by_filter. It seems more consistent to ignore them, as an empty-string element would be ignored. There's a case for back-patching this, since it's clearly a bug fix. On balance though, it doesn't seem like something to change in a minor release. Jean-Christophe Arnu Discussion: https://postgr.es/m/CAHZmTm1YVndPgUVRoag2WL0w900XcoiivDDj-gTTYBsG25c65A@mail.gmail.com
* Allow GRANT on pg_log_backend_memory_contexts().Jeff Davis2021-10-26
| | | | | | | | | | | | | Remove superuser check, allowing any user granted permissions on pg_log_backend_memory_contexts() to log the memory contexts of any backend. Note that this could allow a privileged non-superuser to log the memory contexts of a superuser backend, but as discussed, that does not seem to be a problem. Reviewed-by: Nathan Bossart, Bharath Rupireddy, Michael Paquier, Kyotaro Horiguchi, Andres Freund Discussion: https://postgr.es/m/e5cf6684d17c8d1ef4904ae248605ccd6da03e72.camel@j-davis.com
* Fix EXPLAIN of SEARCH BREADTH FIRST queries some more.Tom Lane2021-10-11
| | | | | | | | | | | | | | | | | | | | 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
* Fix corner-case loss of precision in numeric_power().Dean Rasheed2021-10-06
| | | | | | | | | | | | | | | | | | | | | | | | 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
* Avoid believing incomplete MCV-only stats in get_variable_range().Tom Lane2021-10-01
| | | | | | | | | | | | | | | | | | | | | | get_variable_range() would incautiously believe that statistics containing only an MCV list are sufficient to derive a range estimate. That's okay for an enum-like column that contains only MCVs, but otherwise the estimate could be pretty bad. Make it report that the range is indeterminate unless the MCVs plus nullfrac account for the whole table. I don't think this needs a dedicated test case, since a quick code coverage check verifies that the existing regression tests traverse all the alternatives. There is room to doubt that a future-proof test case could be built anyway, given that the submitted example accidentally doesn't fail before v11. Per bug #17207 from Simon Perepelitsa. Back-patch to v10. In principle this has been broken all along, but I'm hesitant to make such changes in 9.6, since if anyone is unhappy with 9.6.24's behavior there will be no second chance to fix it. Discussion: https://postgr.es/m/17207-5265aefa79e333b4@postgresql.org
* Clarify use of "statistics objects" in the codeMichael Paquier2021-09-29
| | | | | | | | | | | | | | | The code inconsistently used "statistic object" or "statistics" where the correct term, as discussed, is actually "statistics object". This improves the state of the code to be more consistent. While on it, fix an incorrect error message introduced in a4d75c8. This error should never happen, as the code states, but it would be misleading. Author: Justin Pryzby Reviewed-by: Álvaro Herrera, Michael Paquier Discussion: https://postgr.es/m/20210924215827.GS831@telsasoft.com Backpatch-through: 14
* Avoid unnecessary division in interval_cmp_value().Tom Lane2021-09-26
| | | | | | | | | Splitting the time field into days and microseconds is pretty useless when we're just going to recombine those values. It's unclear if anyone will notice the speedup in real-world cases, but a cycle shaved is a cycle earned. Discussion: https://postgr.es/m/2629129.1632675713@sss.pgh.pa.us
* Make use of PG_INT64_MAX/PG_INT64_MINPeter Eisentraut2021-09-22
| | | | | This code was written before those symbols were introduced, but now we can simplify it.
* Fix EXPLAIN to handle SEARCH BREADTH FIRST queries.Tom Lane2021-09-16
| | | | | | | | | | | | | | | | | | | The rewriter transformation for SEARCH BREADTH FIRST produces a FieldSelect on a Var of type RECORD, where the Var references the recursive union's worktable output. EXPLAIN VERBOSE failed to handle this case, because it only expected such Vars to appear in CteScans not WorkTableScans. Fix that, and add some test cases exercising EXPLAIN on SEARCH and CYCLE queries. In principle this oversight is an old bug, but it seems that the case is unreachable without SEARCH BREADTH FIRST, because the parser fails when attempting to create such a reference manually. So for today I'll just patch HEAD/v14. Someday we might find that the code portion of this patch needs to be back-patched further. Per report from Atsushi Torikoshi. Discussion: https://postgr.es/m/5bafa66ad529e11860339565c9e7c166@oss.nttdata.com
* Message style improvementsPeter Eisentraut2021-09-16
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* Remove arbitrary 64K-or-so limit on rangetable size.Tom Lane2021-09-15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Up to now the size of a query's rangetable has been limited by the constants INNER_VAR et al, which mustn't be equal to any real rangetable index. 65000 doubtless seemed like enough for anybody, and it still is orders of magnitude larger than the number of joins we can realistically handle. However, we need a rangetable entry for each child partition that is (or might be) processed by a query. Queries with a few thousand partitions are getting more realistic, so that the day when that limit becomes a problem is in sight, even if it's not here yet. Hence, let's raise the limit. Rather than just increase the values of INNER_VAR et al, this patch adopts the approach of making them small negative values, so that rangetables could theoretically become as long as INT_MAX. The bulk of the patch is concerned with changing Var.varno and some related variables from "Index" (unsigned int) to plain "int". This is basically cosmetic, with little actual effect other than to help debuggers print their values nicely. As such, I've only bothered with changing places that could actually see INNER_VAR et al, which the parser and most of the planner don't. We do have to be careful in places that are performing less/greater comparisons on varnos, but there are very few such places, other than the IS_SPECIAL_VARNO macro itself. A notable side effect of this patch is that while it used to be possible to add INNER_VAR et al to a Bitmapset, that will now draw an error. I don't see any likelihood that it wouldn't be a bug to include these fake varnos in a bitmapset of real varnos, so I think this is all to the good. Although this touches outfuncs/readfuncs, I don't think a catversion bump is required, since stored rules would never contain Vars with these fake varnos. Andrey Lepikhov and Tom Lane, after a suggestion by Peter Eisentraut Discussion: https://postgr.es/m/43c7f2f5-1e27-27aa-8c65-c91859d15190@postgrespro.ru
* Fix hash_arrayPeter Eisentraut2021-09-15
| | | | | | | | | | | Commit a3d2b1bbe904b0ca8d9fdde20f25295ff3e21f79 neglected to initialize the type_id field of the synthesized type cache entry, so it would make a new one on every call. Also, better use the per-function memory context for this; otherwise it leaks memory. Discussion: https://www.postgresql.org/message-id/flat/17158-8a2ba823982537a4%40postgresql.org
* Remove Value node structPeter Eisentraut2021-09-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | The Value node struct is a weird construct. It is its own node type, but most of the time, it actually has a node type of Integer, Float, String, or BitString. As a consequence, the struct name and the node type don't match most of the time, and so it has to be treated specially a lot. There doesn't seem to be any value in the special construct. There is very little code that wants to accept all Value variants but nothing else (and even if it did, this doesn't provide any convenient way to check it), and most code wants either just one particular node type (usually String), or it accepts a broader set of node types besides just Value. This change removes the Value struct and node type and replaces them by separate Integer, Float, String, and BitString node types that are proper node types and structs of their own and behave mostly like normal node types. Also, this removes the T_Null node tag, which was previously also a possible variant of Value but wasn't actually used outside of the Value contained in A_Const. Replace that by an isnull field in A_Const. Reviewed-by: Dagfinn Ilmari Mannsåker <ilmari@ilmari.org> Reviewed-by: Kyotaro Horiguchi <horikyota.ntt@gmail.com> Discussion: https://www.postgresql.org/message-id/flat/5ba6bc5b-3f95-04f2-2419-f8ddb4c046fb@enterprisedb.com
* Fix typoPeter Eisentraut2021-09-08
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* Disable anonymous record hash support except in special casesPeter Eisentraut2021-09-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 01e658fa74 added hash support for row types. This also added support for hashing anonymous record types, using the same approach that the type cache uses for comparison support for record types: It just reports that it works, but it might fail at run time if a component type doesn't actually support the operation. We get away with that for comparison because most types support that. But some types don't support hashing, so the current state can result in failures at run time where the planner chooses hashing over sorting, whereas that previously worked if only sorting was an option. We do, however, want the record hashing support for path tracking in recursive unions, and the SEARCH and CYCLE clauses built on that. In that case, hashing is the only plan option. So enable that, this commit implements the following approach: The type cache does not report that hashing is available for the record type. This undoes that part of 01e658fa74. Instead, callers that require hashing no matter what can override that result themselves. This patch only touches the callers to make the aforementioned recursive query cases work, namely the parse analysis of unions, as well as the hash_array() function. Reported-by: Sait Talha Nisanci <sait.nisanci@microsoft.com> Bug: #17158 Discussion: https://www.postgresql.org/message-id/flat/17158-8a2ba823982537a4%40postgresql.org
* Clean up some code using "(expr) ? true : false"Michael Paquier2021-09-08
| | | | | | | | | | All the code paths simplified here were already using a boolean or used an expression that led to zero or one, making the extra bits unnecessary. Author: Justin Pryzby Reviewed-by: Tom Lane, Michael Paquier, Peter Smith Discussion: https://postgr.es/m/20210428182936.GE27406@telsasoft.com
* Make timetz_zone() stable, and correct a bug for DYNTZ abbreviations.Tom Lane2021-09-06
| | | | | | | | | | | | | | | | | | | | | Historically, timetz_zone() has used time(NULL) as the reference point for deciding whether DST is active. That means its result can change intra-statement, requiring it to be marked VOLATILE (cf. 35979e6c3). But that definition is pretty inconsistent with the way we deal with timestamps elsewhere. Let's make it use the transaction start time ("now()") as the reference point instead. That lets it be marked STABLE, and also saves a kernel call per invocation. While at it, remove the function's use of pg_time_t and pg_localtime. Those are inconsistent with the other code in this area, which indeed created a bug: timetz_zone() delivered completely wrong answers if the zone was specified by a dynamic TZ abbreviation. (We need to do something about that in the back branches, but the fix will look different from this.) Aleksander Alekseev and Tom Lane Discussion: https://postgr.es/m/CAJ7c6TOMG8zSNEZtCn5SPe+cCk3Lfxb71ZaQwT2F4T7PJ_t=KA@mail.gmail.com
* Fix typo in comments.Fujii Masao2021-09-06
| | | | | Author: Hou Zhijie Discussion: https://postgr.es/m/OS0PR01MB5716E6A6535FDFDC5A1B004194CE9@OS0PR01MB5716.jpnprd01.prod.outlook.com
* Don't print extra parens around expressions in extended statsTomas Vondra2021-09-01
| | | | | | | | | | | | | | The code printing expressions for extended statistics doubled the parens, producing results like ((a+1)), which is unnecessary and not consistent with how we print expressions elsewhere. Fixed by tweaking the code to produce just a single set of parens. Reported by Mark Dilger, fix by me. Backpatch to 14, where support for extended statistics on expressions was added. Reported-by: Mark Dilger Discussion: https://postgr.es/m/20210122040101.GF27167%40telsasoft.com
* Fix missed lock acquisition while inlining new-style SQL functions.Tom Lane2021-08-31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | When starting to use a query parsetree loaded from the catalogs, we must begin by applying AcquireRewriteLocks(), to obtain the same relation locks that the parser would have gotten if the query were entered interactively, and to do some other cleanup such as dealing with later-dropped columns. New-style SQL functions are just as subject to this rule as other stored parsetrees; however, of the places dealing with such functions, only init_sql_fcache had gotten the memo. In particular, if we successfully inlined a new-style set-returning SQL function that contained any relation references, we'd either get an assertion failure or attempt to use those relation(s) sans locks. I also added AcquireRewriteLocks calls to fmgr_sql_validator and print_function_sqlbody. Desultory experiments didn't demonstrate any failures in those, but I suspect that I just didn't try hard enough. Certainly we don't expect nearby code paths to operate without locks. On the same logic of it-ought-to-have-the-same-effects-as-the-old-code, call pg_rewrite_query() in fmgr_sql_validator, too. It's possible that neither code path there needs to bother with rewriting, but doing the analysis to prove that is beyond my goals for today. Per bug #17161 from Alexander Lakhin. Discussion: https://postgr.es/m/17161-048a1cdff8422800@postgresql.org
* Remove redundant test.Tom Lane2021-08-25
| | | | | | | | | | The condition "context_start < context_end" is strictly weaker than "context_end - context_start >= 50", so we don't need both. Oversight in commit ffd3944ab, noted by tanghy.fnst. In passing, line-wrap a nearby test to make it more readable. Discussion: https://postgr.es/m/OS0PR01MB61137C4054774F44E3A9DC89FBC69@OS0PR01MB6113.jpnprd01.prod.outlook.com
* Improve error message about valid value for distance in phrase operator.Fujii Masao2021-08-25
| | | | | | | | | | | | | | The distance in phrase operator must be an integer value between zero and MAXENTRYPOS inclusive. But previously the error message about its valid value included the information about its upper limit but not lower limit (i.e., zero). This commit improves the error message so that it also includes the information about its lower limit. Back-patch to v9.6 where full-text phrase search was supported. Author: Kyotaro Horiguchi Reviewed-by: Fujii Masao Discussion: https://postgr.es/m/20210819.170315.1413060634876301811.horikyota.ntt@gmail.com
* Revert refactoring of hex code to src/common/Michael Paquier2021-08-19
| | | | | | | | | | | | | | | | | | | | | | | This is a combined revert of the following commits: - c3826f8, a refactoring piece that moved the hex decoding code to src/common/. This code was cleaned up by aef8948, as it originally included no overflow checks in the same way as the base64 routines in src/common/ used by SCRAM, making it unsafe for its purpose. - aef8948, a more advanced refactoring of the hex encoding/decoding code to src/common/ that added sanity checks on the result buffer for hex decoding and encoding. As reported by Hans Buschmann, those overflow checks are expensive, and it is possible to see a performance drop in the decoding/encoding of bytea or LOs the longer they are. Simple SQLs working on large bytea values show a clear difference in perf profile. - ccf4e27, a cleanup made possible by aef8948. The reverts of all those commits bring back the performance of hex decoding and encoding back to what it was in ~13. Fow now and post-beta3, this is the simplest option. Reported-by: Hans Buschmann Discussion: https://postgr.es/m/1629039545467.80333@nidsa.net Backpatch-through: 14
* Let regexp_replace() make use of REG_NOSUB when feasible.Tom Lane2021-08-09
| | | | | | | | | | | | | | | | | | If the replacement string doesn't contain \1...\9, then we don't need sub-match locations, so we can use the REG_NOSUB optimization here too. There's already a pre-scan of the replacement string to look for backslashes, so extend that to check for digits, and refactor to allow that to happen before we compile the regexp. While at it, try to speed up the pre-scan by using memchr() instead of a handwritten loop. It's likely that this is lost in the noise compared to the regexp processing proper, but maybe not. In any case, this coding is shorter. Also, add some test cases to improve the poor coverage of appendStringInfoRegexpSubstr(). Discussion: https://postgr.es/m/3534632.1628536485@sss.pgh.pa.us
* Avoid determining regexp subexpression matches, when possible.Tom Lane2021-08-09
| | | | | | | | | | | | | | | | | | | | | Identifying the precise match locations for parenthesized subexpressions is a fairly expensive task given the way our regexp engine works, both at regexp compile time (where we must create an optimized NFA for each parenthesized subexpression) and at runtime (where determining exact match locations requires laborious search). Up to now we've made little attempt to optimize this situation. This patch identifies cases where we know at compile time that we won't need to know subexpression match locations, and teaches the regexp compiler to not bother creating per-subexpression regexps for parenthesis pairs that are not referenced by backrefs elsewhere in the regexp. (To preserve semantics, we obviously still have to pin down the match locations of backref references.) Users could have obtained the same results before this by being careful to write "non capturing" parentheses wherever possible, but few people bother with that. Discussion: https://postgr.es/m/2219936.1628115334@sss.pgh.pa.us
* Remove some unnecessary casts in format argumentsPeter Eisentraut2021-08-08
| | | | | | We can use %zd or %zu directly, no need to cast to int. Conversely, some code was casting away from int when it could be using %d directly.
* Adjust the integer overflow tests in the numeric code.Dean Rasheed2021-08-06
| | | | | | | | | | | | | | | | | | | | Formerly, the numeric code tested whether an integer value of a larger type would fit in a smaller type by casting it to the smaller type and then testing if the reverse conversion produced the original value. That's perfectly fine, except that it caused a test failure on buildfarm animal castoroides, most likely due to a compiler bug. Instead, do these tests by comparing against PG_INT16/32_MIN/MAX. That matches existing code in other places, such as int84(), which is more widely tested, and so is less likely to go wrong. While at it, add regression tests covering the numeric-to-int8/4/2 conversions, and adjust the recently added tests to the style of 434ddfb79a (on the v11 branch) to make failures easier to diagnose. Per buildfarm via Tom Lane, reviewed by Tom Lane. Discussion: https://postgr.es/m/2394813.1628179479%40sss.pgh.pa.us
* Fix wordingPeter Eisentraut2021-08-06
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* Fix division-by-zero error in to_char() with 'EEEE' format.Dean Rasheed2021-08-05
| | | | | | | | | | | | | | | | | | | | This fixes a long-standing bug when using to_char() to format a numeric value in scientific notation -- if the value's exponent is less than -NUMERIC_MAX_DISPLAY_SCALE-1 (-1001), it produced a division-by-zero error. The reason for this error was that get_str_from_var_sci() divides its input by 10^exp, which it produced using power_var_int(). However, the underflow test in power_var_int() causes it to return zero if the result scale is too small. That's not a problem for power_var_int()'s only other caller, power_var(), since that limits the rscale to 1000, but in get_str_from_var_sci() the exponent can be much smaller, requiring a much larger rscale. Fix by introducing a new function to compute 10^exp directly, with no rscale limit. This also allows 10^exp to be computed more efficiently, without any numeric multiplication, division or rounding. Discussion: https://postgr.es/m/CAEZATCWhojfH4whaqgUKBe8D5jNHB8ytzemL-PnRx+KCTyMXmg@mail.gmail.com
* pgstat: split reporting/fetching of bgwriter and checkpointer stats.Andres Freund2021-08-04
| | | | | | | | | | | | | | | | These have been unrelated since bgwriter and checkpointer were split into two processes in 806a2aee379. As there several pending patches (shared memory stats, extending the set of tracked IO / buffer statistics) that are made a bit more awkward by the grouping, split them. Done separately to make reviewing easier. This does *not* change the contents of pg_stat_bgwriter or move fields out of bgwriter/checkpointer stats that arguably do not belong in either. However pgstat_fetch_global() was renamed and split into pgstat_fetch_stat_checkpointer() and pgstat_fetch_stat_bgwriter(). Author: Andres Freund <andres@anarazel.de> Discussion: https://postgr.es/m/20210405092914.mmxqe7j56lsjfsej@alap3.anarazel.de
* Add assorted new regexp_xxx SQL functions.Tom Lane2021-08-03
| | | | | | | | | | | | | | | | This patch adds new functions regexp_count(), regexp_instr(), regexp_like(), and regexp_substr(), and extends regexp_replace() with some new optional arguments. All these functions follow the definitions used in Oracle, although there are small differences in the regexp language due to using our own regexp engine -- most notably, that the default newline-matching behavior is different. Similar functions appear in DB2 and elsewhere, too. Aside from easing portability, these functions are easier to use for certain tasks than our existing regexp_match[es] functions. Gilles Darold, heavily revised by me Discussion: https://postgr.es/m/fc160ee0-c843-b024-29bb-97b5da61971f@darold.net
* interval: round values when spilling to monthsBruce Momjian2021-08-03
| | | | | | | | | | | Previously spilled units greater than months were truncated to months. Also document the spill behavior. Reported-by: Bryn Llewelly Discussion: https://postgr.es/m/BDAE4B56-3337-45A2-AC8A-30593849D6C0@yugabyte.com Backpatch-through: master
* Fix corner-case errors and loss of precision in numeric_power().Dean Rasheed2021-07-31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This fixes a couple of related problems that arise when raising numbers to very large powers. Firstly, when raising a negative number to a very large integer power, the result should be well-defined, but the previous code would only cope if the exponent was small enough to go through power_var_int(). Otherwise it would throw an internal error, attempting to take the logarithm of a negative number. Fix this by adding suitable handling to the general case in power_var() to cope with negative bases, checking for integer powers there. Next, when raising a (positive or negative) number whose absolute value is slightly less than 1 to a very large power, the result should approach zero as the power is increased. However, in some cases, for sufficiently large powers, this would lose all precision and return 1 instead of 0. This was due to the way that the local_rscale was being calculated for the final full-precision calculation: local_rscale = rscale + (int) val - ln_dweight + 8 The first two terms on the right hand side are meant to give the number of significant digits required in the result ("val" being the estimated result weight). However, this failed to account for the fact that rscale is clipped to a maximum of NUMERIC_MAX_DISPLAY_SCALE (1000), and the result weight might be less then -1000, causing their sum to be negative, leading to a loss of precision. Fix this by forcing the number of significant digits calculated to be nonnegative. It's OK for it to be zero (when the result weight is less than -1000), since the local_rscale value then includes a few extra digits to ensure an accurate result. Finally, add additional underflow checks to exp_var() and power_var(), so that they consistently return zero for cases like this where the result is indistinguishable from zero. Some paths through this code already returned zero in such cases, but others were throwing overflow errors. Dean Rasheed, reviewed by Yugo Nagata. Discussion: http://postgr.es/m/CAEZATCW6Dvq7+3wN3tt5jLj-FyOcUgT5xNoOqce5=6Su0bCR0w@mail.gmail.com
* Disallow negative strides in date_bin()John Naylor2021-07-28
| | | | | | | | | | | It's not clear what the semantics of negative strides would be, so throw an error instead. Per report from Bauyrzhan Sakhariyev Reviewed-by: Tom Lane, Michael Paquier Discussion: https://www.postgresql.org/message-id/CAKpL73vZmLuFVuwF26FJ%2BNk11PVHhAnQRoREFcA03x7znRoFvA%40mail.gmail.com Backpatch to v14
* Avoid using ambiguous word "non-negative" in error messages.Fujii Masao2021-07-28
| | | | | | | | | | | | | | | | | | | | | | The error messages using the word "non-negative" are confusing because it's ambiguous about whether it accepts zero or not. This commit improves those error messages by replacing it with less ambiguous word like "greater than zero" or "greater than or equal to zero". Also this commit added the note about the word "non-negative" to the error message style guide, to help writing the new error messages. When postgres_fdw option fetch_size was set to zero, previously the error message "fetch_size requires a non-negative integer value" was reported. This error message was outright buggy. Therefore back-patch to all supported versions where such buggy error message could be thrown. Reported-by: Hou Zhijie Author: Bharath Rupireddy Reviewed-by: Kyotaro Horiguchi, Fujii Masao Discussion: https://postgr.es/m/OS0PR01MB5716415335A06B489F1B3A8194569@OS0PR01MB5716.jpnprd01.prod.outlook.com
* Use the "pg_temp" schema alias in EXPLAIN and related output.Tom Lane2021-07-27
| | | | | | | | | | | | | | | | | | | | | | | | | | This patch causes EXPLAIN output to refer to objects that are in the current session's temp schema with the "pg_temp" schema alias rather than that schema's actual name. This is useful for our own testing purposes since it will stabilize EXPLAIN VERBOSE output for such cases, allowing us to use that in regression tests. It should be less confusing for end users too. Since ruleutils.c needs to change behavior for this, the change also leaks into a few other users of ruleutils.c, for example pg_get_viewdef(). AFAICS that won't cause any problems. We did find that aggressively trying to change this behavior across-the-board would cause issues, but as long as "pg_temp" only appears within generated SQL text, I think it'll be fine. Along the way, make get_namespace_name_or_temp conform to the same API as get_namespace_name, ie that it returns a palloc'd string or NULL. The current behavior hasn't caused any bugs since no callers attempt to pfree the result, but if it gets more widespread usage that could become a problem. Amul Sul, reviewed and extended by me Discussion: https://postgr.es/m/CAAJ_b97W=QaGmag9AhWNbmx3uEYsNkXWL+OVW1_E1D3BtgWvtw@mail.gmail.com
* Allow numeric scale to be negative or greater than precision.Dean Rasheed2021-07-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Formerly, when specifying NUMERIC(precision, scale), the scale had to be in the range [0, precision], which was per SQL spec. This commit extends the range of allowed scales to [-1000, 1000], independent of the precision (whose valid range remains [1, 1000]). A negative scale implies rounding before the decimal point. For example, a column might be declared with a scale of -3 to round values to the nearest thousand. Note that the display scale remains non-negative, so in this case the display scale will be zero, and all digits before the decimal point will be displayed. A scale greater than the precision supports fractional values with zeros immediately after the decimal point. Take the opportunity to tidy up the code that packs, unpacks and validates the contents of a typmod integer, encapsulating it in a small set of new inline functions. Bump the catversion because the allowed contents of atttypmod have changed for numeric columns. This isn't a change that requires a re-initdb, but negative scale values in the typmod would confuse old backends. Dean Rasheed, with additional improvements by Tom Lane. Reviewed by Tom Lane. Discussion: https://postgr.es/m/CAEZATCWdNLgpKihmURF8nfofP0RFtAKJ7ktY6GcZOPnMfUoRqA@mail.gmail.com
* Fix division by zero error in date_binJohn Naylor2021-07-22
| | | | | | Bauyrzhan Sakhariyev, via Github Backpatch to v14
* Use l*_node() family of functions where appropriatePeter Eisentraut2021-07-19
| | | | | | | Instead of castNode(…, lfoo(…)) Author: Dagfinn Ilmari Mannsåker <ilmari@ilmari.org> Discussion: https://www.postgresql.org/message-id/flat/87eecahraj.fsf@wibble.ilmari.org
* Support for unnest(multirange)Alexander Korotkov2021-07-18
| | | | | | | | | | | | | | | | It has been spotted that multiranges lack of ability to decompose them into individual ranges. Subscription and proper expanded object representation require substantial work, and it's too late for v14. This commit provides the implementation of unnest(multirange), which is quite trivial. unnest(multirange) is defined as a polymorphic procedure. Catversion is bumped. Reported-by: Jonathan S. Katz Discussion: https://postgr.es/m/flat/60258efe-bd7e-4886-82e1-196e0cac5433%40postgresql.org Author: Alexander Korotkov Reviewed-by: Justin Pryzby, Jonathan S. Katz, Zhihong Yu, Tom Lane Reviewed-by: Alvaro Herrera
* Rename debug_invalidate_system_caches_always to debug_discard_caches.Tom Lane2021-07-13
| | | | | | | | The name introduced by commit 4656e3d66 was agreed to be unreasonably long. To match this change, rename initdb's recently-added --clobber-cache option to --discard-caches. Discussion: https://postgr.es/m/1374320.1625430433@sss.pgh.pa.us
* Fix numeric_mul() overflow due to too many digits after decimal point.Dean Rasheed2021-07-10
| | | | | | | | | This fixes an overflow error when using the numeric * operator if the result has more than 16383 digits after the decimal point by rounding the result. Overflow errors should only occur if the result has too many digits *before* the decimal point. Discussion: https://postgr.es/m/CAEZATCUmeFWCrq2dNzZpRj5+6LfN85jYiDoqm+ucSXhb9U2TbA@mail.gmail.com
* Teach pg_size_pretty and pg_size_bytes about petabytesDavid Rowley2021-07-09
| | | | | | | | | | | | | | | | There was talk about adding units all the way up to yottabytes but it seems quite far-fetched that anyone would need those. Since such large units are not exactly commonplace, it seems unlikely that having pg_size_pretty outputting unit any larger than petabytes would actually be helpful to anyone. Since petabytes are on the horizon, let's just add those only. Maybe one day we'll get to add additional units, but it will likely be a while before we'll need to think beyond petabytes in regards to the size of a database. Author: David Christensen Discussion: https://postgr.es/m/CAOxo6XKmHc_WZip-x5QwaOqFEiCq_SVD0B7sbTZQk+qqcn2qaw@mail.gmail.com
* Use a lookup table for units in pg_size_pretty and pg_size_bytesDavid Rowley2021-07-09
| | | | | | | | | | | | | | | | | | | | | We've grown 2 versions of pg_size_pretty over the years, one for BIGINT and one for NUMERIC. Both should output the same, but keeping them in sync is harder than needed due to neither function sharing a source of truth about which units to use and how to transition to the next largest unit. Here we add a static array which defines the units that we recognize and have both pg_size_pretty and pg_size_pretty_numeric use it. This will make adding any units in the future a very simple task. The table contains all information required to allow us to also modify pg_size_bytes to use the lookup table, so adjust that too. There are no behavioral changes here. Author: David Rowley Reviewed-by: Dean Rasheed, Tom Lane, David Christensen Discussion: https://postgr.es/m/CAApHDvru1F7qsEVL-iOHeezJ+5WVxXnyD_Jo9nht+Eh85ekK-Q@mail.gmail.com
* Fix incorrect return value in pg_size_pretty(bigint)David Rowley2021-07-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Due to how pg_size_pretty(bigint) was implemented, it's possible that when given a negative number of bytes that the returning value would not match the equivalent positive return value when given the equivalent positive number of bytes. This was due to two separate issues. 1. The function used bit shifting to convert the number of bytes into larger units. The rounding performed by bit shifting is not the same as dividing. For example -3 >> 1 = -2, but -3 / 2 = -1. These two operations are only equivalent with positive numbers. 2. The half_rounded() macro rounded towards positive infinity. This meant that negative numbers rounded towards zero and positive numbers rounded away from zero. Here we fix #1 by dividing the values instead of bit shifting. We fix #2 by adjusting the half_rounded macro always to round away from zero. Additionally, adjust the pg_size_pretty(numeric) function to be more explicit that it's using division rather than bit shifting. A casual observer might have believed bit shifting was used due to a static function being named numeric_shift_right. However, that function was calculating the divisor from the number of bits and performed division. Here we make that more clear. This change is just cosmetic and does not affect the return value of the numeric version of the function. Here we also add a set of regression tests both versions of pg_size_pretty() which test the values directly before and after the function switches to the next unit. This bug was introduced in 8a1fab36a. Prior to that negative values were always displayed in bytes. Author: Dean Rasheed, David Rowley Discussion: https://postgr.es/m/CAEZATCXnNW4HsmZnxhfezR5FuiGgp+mkY4AzcL5eRGO4fuadWg@mail.gmail.com Backpatch-through: 9.6, where the bug was introduced.
* Prevent numeric overflows in parallel numeric aggregates.Dean Rasheed2021-07-05
| | | | | | | | | | | | | | | | | | | | | | | | | Formerly various numeric aggregate functions supported parallel aggregation by having each worker convert partial aggregate values to Numeric and use numeric_send() as part of serializing their state. That's problematic, since the range of Numeric is smaller than that of NumericVar, so it's possible for it to overflow (on either side of the decimal point) in cases that would succeed in non-parallel mode. Fix by serializing NumericVars instead, to avoid the overflow risk and ensure that parallel and non-parallel modes work the same. A side benefit is that this improves the efficiency of the serialization/deserialization code, which can make a noticeable difference to performance with large numbers of parallel workers. No back-patch due to risk from changing the binary format of the aggregate serialization states, as well as lack of prior field complaints and low probability of such overflows in practice. Patch by me. Thanks to David Rowley for review and performance testing, and Ranier Vilela for an additional suggestion. Discussion: https://postgr.es/m/CAEZATCUmeFWCrq2dNzZpRj5+6LfN85jYiDoqm+ucSXhb9U2TbA@mail.gmail.com
* Replace magic constants used in pg_stat_get_replication_slot().Amit Kapila2021-06-30
| | | | | | | | | | A few variables have been using 10 as a magic constant while PG_STAT_GET_REPLICATION_SLOT_COLS can be used instead. Author: Masahiko Sawada Reviewed-By: Amit Kapila Backpatch-through: 14, where it was introduced Discussion: https://postgr.es/m/CAD21AoBvqODDfmD17DkEuPCvV2KbruukXQ2Vwrv5Xi-TsAsTJA@mail.gmail.com
* Fixes for multirange selectivity estimationAlexander Korotkov2021-06-29
| | | | | | | | | | | * Fix enumeration of the multirange operators in calc_multirangesel() and calc_multirangesel() switches. * Add more regression tests for matching to empty ranges/multiranges. Reported-by: Alexander Lakhin Discussion: https://postgr.es/m/c5269c65-f967-77c5-ff7c-15e621c47f6a%40gmail.com Author: Alexander Korotkov Backpatch-through: 14, where multiranges were introduced