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path: root/src/backend/utils/adt/ruleutils.c
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2019-11-16Further fix dumping of views that contain just VALUES(...).Tom Lane
It turns out that commit e9f1c01b7 missed a case: we must print a VALUES clause in long format if get_query_def is given a resultDesc that would require the query's output column name(s) to be different from what the bare VALUES clause would produce. This applies in case an ALTER ... RENAME COLUMN has been done to a view that formerly could be printed in simple format, as shown in the added regression test case. It also explains bug #16119 from Dmitry Telpt, because it turns out that (unlike CREATE VIEW) CREATE MATERIALIZED VIEW fails to apply any column aliases it's given to the stored ON SELECT rule. So to get them to be printed, we have to account for the resultDesc renaming. It might be worth changing the matview code so that it creates the ON SELECT rule with the correct aliases; but we'd still need these messy checks in get_simple_values_rte to handle the case of a subsequent column rename, so any such change would be just neatnik-ism not a bug fix. Like the previous patch, back-patch to all supported branches. Discussion: https://postgr.es/m/16119-e64823f30a45a754@postgresql.org
2019-08-05Require the schema qualification in pg_temp.type_name(arg).Noah Misch
Commit aa27977fe21a7dfa4da4376ad66ae37cb8f0d0b5 introduced this restriction for pg_temp.function_name(arg); do likewise for types created in temporary schemas. Programs that this breaks should add "pg_temp." schema qualification or switch to arg::type_name syntax. Back-patch to 9.4 (all supported versions). Reviewed by Tom Lane. Reported by Tom Lane. Security: CVE-2019-10208
2019-06-12Fix incorrect printing of queries with duplicated join names.Tom Lane
Given a query in which multiple JOIN nodes used the same alias (which'd necessarily be in different sub-SELECTs), ruleutils.c would assign the JOIN nodes distinct aliases for clarity ... but then it forgot to print the modified aliases when dumping the JOIN nodes themselves. This results in a dump/reload hazard for views, because the emitted query is flat-out incorrect: Vars will be printed with table names that have no referent. This has been wrong for a long time, so back-patch to all supported branches. Philip Dubé Discussion: https://postgr.es/m/CY4PR2101MB080246F2955FF58A6ED1FEAC98140@CY4PR2101MB0802.namprd21.prod.outlook.com
2018-07-31Further fixes for quoted-list GUC values in pg_dump and ruleutils.c.Tom Lane
Commits 742869946 et al turn out to be a couple bricks shy of a load. We were dumping the stored values of GUC_LIST_QUOTE variables as they appear in proconfig or setconfig catalog columns. However, although that quoting rule looks a lot like SQL-identifier double quotes, there are two critical differences: empty strings ("") are legal, and depending on which variable you're considering, values longer than NAMEDATALEN might be valid too. So the current technique fails altogether on empty-string list entries (as reported by Steven Winfield in bug #15248) and it also risks truncating file pathnames during dump/reload of GUC values that are lists of pathnames. To fix, split the stored value without any downcasing or truncation, and then emit each element as a SQL string literal. This is a tad annoying, because we now have three copies of the comma-separated-string splitting logic in varlena.c as well as a fourth one in dumputils.c. (Not to mention the randomly-different-from-those splitting logic in libpq...) I looked at unifying these, but it would be rather a mess unless we're willing to tweak the API definitions of SplitIdentifierString, SplitDirectoriesString, or both. That might be worth doing in future; but it seems pretty unsafe for a back-patched bug fix, so for now accept the duplication. Back-patch to all supported branches, as the previous fix was. Discussion: https://postgr.es/m/7585.1529435872@sss.pgh.pa.us
2018-07-28Document security implications of qualified names.Noah Misch
Commit 5770172cb0c9df9e6ce27c507b449557e5b45124 documented secure schema usage, and that advice suffices for using unqualified names securely. Document, in typeconv-func primarily, the additional issues that arise with qualified names. Back-patch to 9.3 (all supported versions). Reviewed by Jonathan S. Katz. Discussion: https://postgr.es/m/20180721012446.GA1840594@rfd.leadboat.com
2018-03-21Fix mishandling of quoted-list GUC values in pg_dump and ruleutils.c.Tom Lane
Code that prints out the contents of setconfig or proconfig arrays in SQL format needs to handle GUC_LIST_QUOTE variables differently from other ones, because for those variables, flatten_set_variable_args() already applied a layer of quoting. The value can therefore safely be printed as-is, and indeed must be, or flatten_set_variable_args() will muck it up completely on reload. For all other GUC variables, it's necessary and sufficient to quote the value as a SQL literal. We'd recognized the need for this long ago, but mis-analyzed the need slightly, thinking that all GUC_LIST_INPUT variables needed the special treatment. That's actually wrong, since a valid value of a LIST variable might include characters that need quoting, although no existing variables accept such values. More to the point, we hadn't made any particular effort to keep the various places that deal with this up-to-date with the set of variables that actually need special treatment, meaning that we'd do the wrong thing with, for example, temp_tablespaces values. This affects dumping of SET clauses attached to functions, as well as ALTER DATABASE/ROLE SET commands. In ruleutils.c we can fix it reasonably honestly by exporting a guc.c function that allows discovering the flags for a given GUC variable. But pg_dump doesn't have easy access to that, so continue the old method of having a hard-wired list of affected variable names. At least we can fix it to have just one list not two, and update the list to match current reality. A remaining problem with this is that it only works for built-in GUC variables. pg_dump's list obvious knows nothing of third-party extensions, and even the "ask guc.c" method isn't bulletproof since the relevant extension might not be loaded. There's no obvious solution to that, so for now, we'll just have to discourage extension authors from inventing custom GUCs that need GUC_LIST_QUOTE. This has been busted for a long time, so back-patch to all supported branches. Michael Paquier and Tom Lane, reviewed by Kyotaro Horiguchi and Pavel Stehule Discussion: https://postgr.es/m/20180111064900.GA51030@paquier.xyz
2018-03-19Fix some corner-case issues in REFRESH MATERIALIZED VIEW CONCURRENTLY.Tom Lane
refresh_by_match_merge() has some issues in the way it builds a SQL query to construct the "diff" table: 1. It doesn't require the selected unique index(es) to be indimmediate. 2. It doesn't pay attention to the particular equality semantics enforced by a given index, but just assumes that they must be those of the column datatype's default btree opclass. 3. It doesn't check that the indexes are btrees. 4. It's insufficiently careful to ensure that the parser will pick the intended operator when parsing the query. (This would have been a security bug before CVE-2018-1058.) 5. It's not careful about indexes on system columns. The way to fix #4 is to make use of the existing code in ri_triggers.c for generating an arbitrary binary operator clause. I chose to move that to ruleutils.c, since that seems a more reasonable place to be exporting such functionality from than ri_triggers.c. While #1, #3, and #5 are just latent given existing feature restrictions, and #2 doesn't arise in the core system for lack of alternate opclasses with different equality behaviors, #4 seems like an issue worth back-patching. That's the bulk of the change anyway, so just back-patch the whole thing to 9.4 where this code was introduced. Discussion: https://postgr.es/m/13836.1521413227@sss.pgh.pa.us
2018-02-26Avoid using unsafe search_path settings during dump and restore.Tom Lane
Historically, pg_dump has "set search_path = foo, pg_catalog" when dumping an object in schema "foo", and has also caused that setting to be used while restoring the object. This is problematic because functions and operators in schema "foo" could capture references meant to refer to pg_catalog entries, both in the queries issued by pg_dump and those issued during the subsequent restore run. That could result in dump/restore misbehavior, or in privilege escalation if a nefarious user installs trojan-horse functions or operators. This patch changes pg_dump so that it does not change the search_path dynamically. The emitted restore script sets the search_path to what was used at dump time, and then leaves it alone thereafter. Created objects are placed in the correct schema, regardless of the active search_path, by dint of schema-qualifying their names in the CREATE commands, as well as in subsequent ALTER and ALTER-like commands. Since this change requires a change in the behavior of pg_restore when processing an archive file made according to this new convention, bump the archive file version number; old versions of pg_restore will therefore refuse to process files made with new versions of pg_dump. Security: CVE-2018-1058
2017-07-24Ensure that pg_get_ruledef()'s output matches pg_get_viewdef()'s.Tom Lane
Various cases involving renaming of view columns are handled by having make_viewdef pass down the view's current relation tupledesc to get_query_def, which then takes care to use the column names from the tupledesc for the output column names of the SELECT. For some reason though, we'd missed teaching make_ruledef to do similarly when it is printing an ON SELECT rule, even though this is exactly the same case. The results from pg_get_ruledef would then be different and arguably wrong. In particular, this breaks pre-v10 versions of pg_dump, which in some situations would define views by means of emitting a CREATE RULE ... ON SELECT command. Third-party tools might not be happy either. In passing, clean up some crufty code in make_viewdef; we'd apparently modernized the equivalent code in make_ruledef somewhere along the way, and missed this copy. Per report from Gilles Darold. Back-patch to all supported versions. Discussion: https://postgr.es/m/ec05659a-40ff-4510-fc45-ca9d965d0838@dalibo.com
2017-07-20Fix dumping of outer joins with empty qual lists.Tom Lane
Normally, a JoinExpr would have empty "quals" only if it came from CROSS JOIN syntax. However, it's possible to get to this state by specifying NATURAL JOIN between two tables with no common column names, and there might be other ways too. The code previously printed no ON clause if "quals" was empty; that's right for CROSS JOIN but syntactically invalid if it's some type of outer join. Fix by printing ON TRUE in that case. This got broken by commit 2ffa740be, which stopped using NATURAL JOIN syntax in ruleutils output due to its brittleness in the face of column renamings. Back-patch to 9.3 where that commit appeared. Per report from Tushar Ahuja. Discussion: https://postgr.es/m/98b283cd-6dda-5d3f-f8ac-87db8c76a3da@enterprisedb.com
2017-07-13Fix dumping of FUNCTION RTEs that contain non-function-call expressions.Tom Lane
The grammar will only accept something syntactically similar to a function call in a function-in-FROM expression. However, there are various ways to input something that ruleutils.c won't deparse that way, potentially leading to a view or rule that fails dump/reload. Fix by inserting a dummy CAST around anything that isn't going to deparse as a function (which is one of the ways to get something like that in there in the first place). In HEAD, also make use of the infrastructure added by this to avoid emitting unnecessary parentheses in CREATE INDEX deparsing. I did not change that in back branches, thinking that people might find it to be unexpected/unnecessary behavioral change. In HEAD, also fix incorrect logic for when to add extra parens to partition key expressions. Somebody apparently thought they could get away with simpler logic than pg_get_indexdef_worker has, but they were wrong --- a counterexample is PARTITION BY LIST ((a[1])). Ignoring the prettyprint flag for partition expressions isn't exactly a nice solution anyway. This has been broken all along, so back-patch to all supported branches. Discussion: https://postgr.es/m/10477.1499970459@sss.pgh.pa.us
2017-07-12Fix ruleutils.c for domain-over-array cases, too.Tom Lane
Further investigation shows that ruleutils isn't quite up to speed either for cases where we have a domain-over-array: it needs to be prepared to look past a CoerceToDomain at the top level of field and element assignments, else it decompiles them incorrectly. Potentially this would result in failure to dump/reload a rule, if it looked like the one in the new test case. (I also added a test for EXPLAIN; that output isn't broken, but clearly we need more test coverage here.) Like commit b1cb32fb6, this bug is reachable in cases we already support, so back-patch all the way.
2017-02-06Fix typos in comments.Heikki Linnakangas
Backpatch to all supported versions, where applicable, to make backpatching of future fixes go more smoothly. Josh Soref Discussion: https://www.postgresql.org/message-id/CACZqfqCf+5qRztLPgmmosr-B0Ye4srWzzw_mo4c_8_B_mtjmJQ@mail.gmail.com
2016-11-23Make sure ALTER TABLE preserves index tablespaces.Tom Lane
When rebuilding an existing index, ALTER TABLE correctly kept the physical file in the same tablespace, but it messed up the pg_class entry if the index had been in the database's default tablespace and "default_tablespace" was set to some non-default tablespace. This led to an inaccessible index. Fix by fixing pg_get_indexdef_string() to always include a tablespace clause, whether or not the index is in the default tablespace. The previous behavior was installed in commit 537e92e41, and I think it just wasn't thought through very clearly; certainly the possible effect of default_tablespace wasn't considered. There's some risk in changing the behavior of this function, but there are no other call sites in the core code. Even if it's being used by some third party extension, it's fairly hard to envision a usage that is okay with a tablespace clause being appended some of the time but can't handle it being appended all the time. Back-patch to all supported versions. Code fix by me, investigation and test cases by Michael Paquier. Discussion: <1479294998857-5930602.post@n3.nabble.com>
2016-08-07Fix crash when pg_get_viewdef_name_ext() is passed a non-view relation.Tom Lane
Oversight in commit 976b24fb4. Andreas Seltenreich Report: <87y448l3ag.fsf@credativ.de>
2016-08-03Make INSERT-from-multiple-VALUES-rows handle targetlist indirection better.Tom Lane
Previously, if an INSERT with multiple rows of VALUES had indirection (array subscripting or field selection) in its target-columns list, the parser handled that by applying transformAssignedExpr() to each element of each VALUES row independently. This led to having ArrayRef assignment nodes or FieldStore nodes in each row of the VALUES RTE. That works for simple cases, but in bug #14265 Nuri Boardman points out that it fails if there are multiple assignments to elements/fields of the same target column. For such cases to work, rewriteTargetListIU() has to nest the ArrayRefs or FieldStores together to produce a single expression to be assigned to the column. But it failed to find them in the top-level targetlist and issued an error about "multiple assignments to same column". We could possibly fix this by teaching the rewriter to apply rewriteTargetListIU to each VALUES row separately, but that would be messy (it would change the output rowtype of the VALUES RTE, for example) and inefficient. Instead, let's fix the parser so that the VALUES RTE outputs are just the user-specified values, cast to the right type if necessary, and then the ArrayRefs or FieldStores are applied in the top-level targetlist to Vars representing the RTE's outputs. This is the same parsetree representation already used for similar cases with INSERT/SELECT syntax, so it allows simplifications in ruleutils.c, which no longer needs to treat INSERT-from-multiple-VALUES as its own special case. This implementation works by applying transformAssignedExpr to the VALUES entries as before, and then stripping off any ArrayRefs or FieldStores it adds. With lots of VALUES rows it would be noticeably more efficient to not add those nodes in the first place. But that's just an optimization not a bug fix, and there doesn't seem to be any good way to do it without significant refactoring. (A non-invasive answer would be to apply transformAssignedExpr + stripping to just the first VALUES row, and then just forcibly cast remaining rows to the same data types exposed in the first row. But this way would lead to different, not-INSERT-specific errors being reported in casting failure cases, so it doesn't seem very nice.) So leave that for later; this patch at least isn't making the per-row parsing work worse, and it does make the finished parsetree smaller, saving rewriter and planner work. Catversion bump because stored rules containing such INSERTs would need to change. Because of that, no back-patch, even though this is a very long-standing bug. Report: <20160727005725.7438.26021@wrigleys.postgresql.org> Discussion: <9578.1469645245@sss.pgh.pa.us>
2016-07-29Eliminate a few more user-visible "cache lookup failed" errors.Robert Haas
Michael Paquier
2016-07-28Fix assorted fallout from IS [NOT] NULL patch.Tom Lane
Commits 4452000f3 et al established semantics for NullTest.argisrow that are a bit different from its initial conception: rather than being merely a cache of whether we've determined the input to have composite type, the flag now has the further meaning that we should apply field-by-field testing as per the standard's definition of IS [NOT] NULL. If argisrow is false and yet the input has composite type, the construct instead has the semantics of IS [NOT] DISTINCT FROM NULL. Update the comments in primnodes.h to clarify this, and fix ruleutils.c and deparse.c to print such cases correctly. In the case of ruleutils.c, this merely results in cosmetic changes in EXPLAIN output, since the case can't currently arise in stored rules. However, it represents a live bug for deparse.c, which would formerly have sent a remote query that had semantics different from the local behavior. (From the user's standpoint, this means that testing a remote nested-composite column for null-ness could have had unexpected recursive behavior much like that fixed in 4452000f3.) In a related but somewhat independent fix, make plancat.c set argisrow to false in all NullTest expressions constructed to represent "attnotnull" constructs. Since attnotnull is actually enforced as a simple null-value check, this is a more accurate representation of the semantics; we were previously overpromising what it meant for composite columns, which might possibly lead to incorrect planner optimizations. (It seems that what the SQL spec expects a NOT NULL constraint to mean is an IS NOT NULL test, so arguably we are violating the spec and should fix attnotnull to do the other thing. If we ever do, this part should get reverted.) Back-patch, same as the previous commit. Discussion: <10682.1469566308@sss.pgh.pa.us>
2016-07-26Change various deparsing functions to return NULL for invalid input.Robert Haas
Previously, some functions returned various fixed strings and others failed with a cache lookup error. Per discussion, standardize on returning NULL. Although user-exposed "cache lookup failed" error messages might normally qualify for bug-fix treatment, no back-patch; the risk of breaking user code which is accustomed to the current behavior seems too high. Michael Paquier
2016-07-01Be more paranoid in ruleutils.c's get_variable().Tom Lane
We were merely Assert'ing that the Var matched the RTE it's supposedly from. But if the user passes incorrect information to pg_get_expr(), the RTE might in fact not match; this led either to Assert failures or core dumps, as reported by Chris Hanks in bug #14220. To fix, just convert the Asserts to test-and-elog. Adjust an existing test-and-elog elsewhere in the same function to be consistent in wording. (If we really felt these were user-facing errors, we might promote them to ereport's; but I can't convince myself that they're worth translating.) Back-patch to 9.3; the problematic code doesn't exist before that, and a quick check says that 9.2 doesn't crash on such cases. Michael Paquier and Thomas Munro Report: <20160629224349.1407.32667@wrigleys.postgresql.org>
2016-06-26Rethink node-level representation of partial-aggregation modes.Tom Lane
The original coding had three separate booleans representing partial aggregation behavior, which was confusing, unreadable, and error-prone, not least because the booleans weren't always listed in the same order. It was also inadequate for the allegedly-desirable future extension to support intermediate partial aggregation, because we'd need separate markers for serialization and deserialization in such a case. Merge these bools into an enum "AggSplit" to provide symbolic names for the supported operating modes (and document what those are). By assigning the values of the enum constants carefully, we can treat AggSplit values as options bitmasks so that tests of what to do aren't noticeably more expensive than before. While at it, get rid of Aggref.aggoutputtype. That's not needed since commit 59a3795c2 got rid of setrefs.c's special-purpose Aggref comparison code, and it likewise seemed more confusing than helpful. Assorted comment cleanup as well (there's still more that I want to do in that line). catversion bump for change in Aggref node contents. Should be the last one for partial-aggregation changes. Discussion: <29309.1466699160@sss.pgh.pa.us>
2016-05-11Fix assorted missing infrastructure for ON CONFLICT.Tom Lane
subquery_planner() failed to apply expression preprocessing to the arbiterElems and arbiterWhere fields of an OnConflictExpr. No doubt the theory was that this wasn't necessary because we don't actually try to execute those expressions; but that's wrong, because it results in failure to match to index expressions or index predicates that are changed at all by preprocessing. Per bug #14132 from Reynold Smith. Also add pullup_replace_vars processing for onConflictWhere. Perhaps it's impossible to have a subquery reference there, but I'm not exactly convinced; and even if true today it's a failure waiting to happen. Also add some comments to other places where one or another field of OnConflictExpr is intentionally ignored, with explanation as to why it's okay to do so. Also, catalog/dependency.c failed to record any dependency on the named constraint in ON CONFLICT ON CONSTRAINT, allowing such a constraint to be dropped while rules exist that depend on it, and allowing pg_dump to dump such a rule before the constraint it refers to. The normal execution path managed to error out reasonably for a dangling constraint reference, but ruleutils.c dumped core; so in addition to fixing the omission, add a protective check in ruleutils.c, since we can't retroactively add a dependency in existing databases. Back-patch to 9.5 where this code was introduced. Report: <20160510190350.2608.48667@wrigleys.postgresql.org>
2016-04-27Fix EXPLAIN VERBOSE output for parallel aggregate.Robert Haas
The way that PartialAggregate and FinalizeAggregate plan nodes were displaying output columns before was bogus. Now, FinalizeAggregate produces the same outputs as an Aggregate would have produced, while PartialAggregate produces each of those outputs prefixed by the word PARTIAL. Discussion: 12585.1460737650@sss.pgh.pa.us Patch by me, reviewed by David Rowley.
2016-04-26Fix pg_get_functiondef to dump parallel-safety markings.Robert Haas
Ashutosh Sharma
2016-04-21Fix ruleutils.c's dumping of ScalarArrayOpExpr containing an EXPR_SUBLINK.Tom Lane
When we shoehorned "x op ANY (array)" into the SQL syntax, we created a fundamental ambiguity as to the proper treatment of a sub-SELECT on the righthand side: perhaps what's meant is to compare x against each row of the sub-SELECT's result, or perhaps the sub-SELECT is meant as a scalar sub-SELECT that delivers a single array value whose members should be compared against x. The grammar resolves it as the former case whenever the RHS is a select_with_parens, making the latter case hard to reach --- but you can get at it, with tricks such as attaching a no-op cast to the sub-SELECT. Parse analysis would throw away the no-op cast, leaving a parsetree with an EXPR_SUBLINK SubLink directly under a ScalarArrayOpExpr. ruleutils.c was not clued in on this fine point, and would naively emit "x op ANY ((SELECT ...))", which would be parsed as the first alternative, typically leading to errors like "operator does not exist: text = text[]" during dump/reload of a view or rule containing such a construct. To fix, emit a no-op cast when dumping such a parsetree. This might well be exactly what the user wrote to get the construct accepted in the first place; and even if she got there with some other dodge, it is a valid representation of the parsetree. Per report from Karl Czajkowski. He mentioned only a case involving RLS policies, but actually the problem is very old, so back-patch to all supported branches. Report: <20160421001832.GB7976@moraine.isi.edu>
2016-04-08Revert CREATE INDEX ... INCLUDING ...Teodor Sigaev
It's not ready yet, revert two commits 690c543550b0d2852060c18d270cdb534d339d9a - unstable test output 386e3d7609c49505e079c40c65919d99feb82505 - patch itself
2016-04-08CREATE INDEX ... INCLUDING (column[, ...])Teodor Sigaev
Now indexes (but only B-tree for now) can contain "extra" column(s) which doesn't participate in index structure, they are just stored in leaf tuples. It allows to use index only scan by using single index instead of two or more indexes. Author: Anastasia Lubennikova with minor editorializing by me Reviewers: David Rowley, Peter Geoghegan, Jeff Janes
2016-03-23Move keywords.c/kwlookup.c into src/common/.Tom Lane
Now that we have src/common/ for code shared between frontend and backend, we can get rid of (most of) the klugy ways that the keyword table and keyword lookup code were formerly shared between different uses. This is a first step towards a more general plan of getting rid of special-purpose kluges for sharing code in src/bin/. I chose to merge kwlookup.c back into keywords.c, as it once was, and always has been so far as keywords.h is concerned. We could have kept them separate, but there is noplace that uses ScanKeywordLookup without also wanting access to the backend's keyword list, so there seems little point. ecpg is still a bit weird, but at least now the trickiness is documented. I think that the MSVC build script should require no adjustments beyond what's done here ... but we'll soon find out.
2016-02-07Fix deparsing of ON CONFLICT arbiter WHERE clauses.Tom Lane
The parser doesn't allow qualification of column names appearing in these clauses, but ruleutils.c would sometimes qualify them, leading to dump/reload failures. Per bug #13891 from Onder Kalaci. (In passing, make stanzas in ruleutils.c that save/restore varprefix more consistent.) Peter Geoghegan
2016-01-17Restructure index access method API to hide most of it at the C level.Tom Lane
This patch reduces pg_am to just two columns, a name and a handler function. All the data formerly obtained from pg_am is now provided in a C struct returned by the handler function. This is similar to the designs we've adopted for FDWs and tablesample methods. There are multiple advantages. For one, the index AM's support functions are now simple C functions, making them faster to call and much less error-prone, since the C compiler can now check function signatures. For another, this will make it far more practical to define index access methods in installable extensions. A disadvantage is that SQL-level code can no longer see attributes of index AMs; in particular, some of the crosschecks in the opr_sanity regression test are no longer possible from SQL. We've addressed that by adding a facility for the index AM to perform such checks instead. (Much more could be done in that line, but for now we're content if the amvalidate functions more or less replace what opr_sanity used to do.) We might also want to expose some sort of reporting functionality, but this patch doesn't do that. Alexander Korotkov, reviewed by Petr Jelínek, and rather heavily editorialized on by me.
2016-01-02Update copyright for 2016Bruce Momjian
Backpatch certain files through 9.1
2016-01-01Teach flatten_reloptions() to quote option values safely.Tom Lane
flatten_reloptions() supposed that it didn't really need to do anything beyond inserting commas between reloption array elements. However, in principle the value of a reloption could be nearly anything, since the grammar allows a quoted string there. Any restrictions on it would come from validity checking appropriate to the particular option, if any. A reloption value that isn't a simple identifier or number could thus lead to dump/reload failures due to syntax errors in CREATE statements issued by pg_dump. We've gotten away with not worrying about this so far with the core-supported reloptions, but extensions might allow reloption values that cause trouble, as in bug #13840 from Kouhei Sutou. To fix, split the reloption array elements explicitly, and then convert any value that doesn't look like a safe identifier to a string literal. (The details of the quoting rule could be debated, but this way is safe and requires little code.) While we're at it, also quote reloption names if they're not safe identifiers; that may not be a likely problem in the field, but we might as well try to be bulletproof here. It's been like this for a long time, so back-patch to all supported branches. Kouhei Sutou, adjusted some by me
2015-12-22Allow omitting one or both boundaries in an array slice specifier.Tom Lane
Omitted boundaries represent the upper or lower limit of the corresponding array subscript. This allows simpler specification of many common use-cases. (Revised version of commit 9246af6799819847faa33baf441251003acbb8fe) YUriy Zhuravlev
2015-11-20Fix handling of inherited check constraints in ALTER COLUMN TYPE (again).Tom Lane
The previous way of reconstructing check constraints was to do a separate "ALTER TABLE ONLY tab ADD CONSTRAINT" for each table in an inheritance hierarchy. However, that way has no hope of reconstructing the check constraints' own inheritance properties correctly, as pointed out in bug #13779 from Jan Dirk Zijlstra. What we should do instead is to do a regular "ALTER TABLE", allowing recursion, at the topmost table that has a particular constraint, and then suppress the work queue entries for inherited instances of the constraint. Annoyingly, we'd tried to fix this behavior before, in commit 5ed6546cf, but we failed to notice that it wasn't reconstructing the pg_constraint field values correctly. As long as I'm touching pg_get_constraintdef_worker anyway, tweak it to always schema-qualify the target table name; this seems like useful backup to the protections installed by commit 5f173040. In HEAD/9.5, get rid of get_constraint_relation_oids, which is now unused. (I could alternatively have modified it to also return conislocal, but that seemed like a pretty single-purpose API, so let's not pretend it has some other use.) It's unused in the back branches as well, but I left it in place just in case some third-party code has decided to use it. In HEAD/9.5, also rename pg_get_constraintdef_string to pg_get_constraintdef_command, as the previous name did nothing to explain what that entry point did differently from others (and its comment was equally useless). Again, that change doesn't seem like material for back-patching. I did a bit of re-pgindenting in tablecmds.c in HEAD/9.5, as well. Otherwise, back-patch to all supported branches.
2015-11-16Speed up ruleutils' name de-duplication code, and fix overlength-name case.Tom Lane
Since commit 11e131854f8231a21613f834c40fe9d046926387, ruleutils.c has attempted to ensure that each RTE in a query or plan tree has a unique alias name. However, the code that was added for this could be quite slow, even as bad as O(N^3) if N identical RTE names must be replaced, as noted by Jeff Janes. Improve matters by building a transient hash table within set_rtable_names. The hash table in itself reduces the cost of detecting a duplicate from O(N) to O(1), and we can save another factor of N by storing the number of de-duplicated names already created for each entry, so that we don't have to re-try names already created. This way is probably a bit slower overall for small range tables, but almost by definition, such cases should not be a performance problem. In principle the same problem applies to the column-name-de-duplication code; but in practice that seems to be less of a problem, first because N is limited since we don't support extremely wide tables, and second because duplicate column names within an RTE are fairly rare, so that in practice the cost is more like O(N^2) not O(N^3). It would be very much messier to fix the column-name code, so for now I've left that alone. An independent problem in the same area was that the de-duplication code paid no attention to the identifier length limit, and would happily produce identifiers that were longer than NAMEDATALEN and wouldn't be unique after truncation to NAMEDATALEN. This could result in dump/reload failures, or perhaps even views that silently behaved differently than before. We can fix that by shortening the base name as needed. Fix it for both the relation and column name cases. In passing, check for interrupts in set_rtable_names, just in case it's still slow enough to be an issue. Back-patch to 9.3 where this code was introduced.
2015-11-15Fix ruleutils.c's dumping of whole-row Vars in ROW() and VALUES() contexts.Tom Lane
Normally ruleutils prints a whole-row Var as "foo.*". We already knew that that doesn't work at top level of a SELECT list, because the parser would treat the "*" as a directive to expand the reference into separate columns, not a whole-row Var. However, Joshua Yanovski points out in bug #13776 that the same thing happens at top level of a ROW() construct; and some nosing around in the parser shows that the same is true in VALUES(). Hence, apply the same workaround already devised for the SELECT-list case, namely to add a forced cast to the appropriate rowtype in these cases. (The alternative of just printing "foo" was rejected because it is difficult to avoid ambiguity against plain columns named "foo".) Back-patch to all supported branches.
2015-07-25Redesign tablesample method API, and do extensive code review.Tom Lane
The original implementation of TABLESAMPLE modeled the tablesample method API on index access methods, which wasn't a good choice because, without specialized DDL commands, there's no way to build an extension that can implement a TSM. (Raw inserts into system catalogs are not an acceptable thing to do, because we can't undo them during DROP EXTENSION, nor will pg_upgrade behave sanely.) Instead adopt an API more like procedural language handlers or foreign data wrappers, wherein the only SQL-level support object needed is a single handler function identified by having a special return type. This lets us get rid of the supporting catalog altogether, so that no custom DDL support is needed for the feature. Adjust the API so that it can support non-constant tablesample arguments (the original coding assumed we could evaluate the argument expressions at ExecInitSampleScan time, which is undesirable even if it weren't outright unsafe), and discourage sampling methods from looking at invisible tuples. Make sure that the BERNOULLI and SYSTEM methods are genuinely repeatable within and across queries, as required by the SQL standard, and deal more honestly with methods that can't support that requirement. Make a full code-review pass over the tablesample additions, and fix assorted bugs, omissions, infelicities, and cosmetic issues (such as failure to put the added code stanzas in a consistent ordering). Improve EXPLAIN's output of tablesample plans, too. Back-patch to 9.5 so that we don't have to support the original API in production.
2015-07-02Use appendStringInfoString/Char et al where appropriate.Heikki Linnakangas
Patch by David Rowley. Backpatch to 9.5, as some of the calls were new in 9.5, and keeping the code in sync with master makes future backpatching easier.
2015-06-27Avoid passing NULL to memcmp() in lookups of zero-argument functions.Tom Lane
A few places assumed they could pass NULL for the argtypes array when looking up functions known to have zero arguments. At first glance it seems that this should be safe enough, since memcmp() is surely not allowed to fetch any bytes if its count argument is zero. However, close reading of the C standard says that such calls have undefined behavior, so we'd probably best avoid it. Since the number of places doing this is quite small, and some other places looking up zero-argument functions were already passing dummy arrays, let's standardize on the latter solution rather than hacking the function lookup code to avoid calling memcmp() in these cases. I also added Asserts to catch any future violations of the new rule. Given the utter lack of any evidence that this actually causes any problems in the field, I don't feel a need to back-patch this change. Per report from Piotr Stefaniak, though this is not his patch.
2015-05-28Fix pg_get_functiondef() to print a function's LEAKPROOF property.Tom Lane
Seems to have been an oversight in the original leakproofness patch. Per report and patch from Jeevan Chalke. In passing, prettify some awkward leakproof-related code in AlterFunction.
2015-05-24Manual cleanup of pgindent results.Tom Lane
Fix some places where pgindent did silly stuff, often because project style wasn't followed to begin with. (I've not touched the atomics headers, though.)
2015-05-23pgindent run for 9.5Bruce Momjian
2015-05-23Fix yet another bug in ON CONFLICT rule deparsing.Andres Freund
Expand testing of rule deparsing a good bit, it's evidently needed. Author: Peter Geoghegan, Andres Freund Discussion: CAM3SWZQmXxZhQC32QVEOTYfNXJBJ_Q2SDENL7BV14Cq-zL0FLg@mail.gmail.com
2015-05-19Various fixes around ON CONFLICT for rule deparsing.Andres Freund
Neither the deparsing of the new alias for INSERT's target table, nor of the inference clause was supported. Also fixup a typo in an error message. Add regression tests to test those code paths. Author: Peter Geoghegan
2015-05-16Support GROUPING SETS, CUBE and ROLLUP.Andres Freund
This SQL standard functionality allows to aggregate data by different GROUP BY clauses at once. Each grouping set returns rows with columns grouped by in other sets set to NULL. This could previously be achieved by doing each grouping as a separate query, conjoined by UNION ALLs. Besides being considerably more concise, grouping sets will in many cases be faster, requiring only one scan over the underlying data. The current implementation of grouping sets only supports using sorting for input. Individual sets that share a sort order are computed in one pass. If there are sets that don't share a sort order, additional sort & aggregation steps are performed. These additional passes are sourced by the previous sort step; thus avoiding repeated scans of the source data. The code is structured in a way that adding support for purely using hash aggregation or a mix of hashing and sorting is possible. Sorting was chosen to be supported first, as it is the most generic method of implementation. Instead of, as in an earlier versions of the patch, representing the chain of sort and aggregation steps as full blown planner and executor nodes, all but the first sort are performed inside the aggregation node itself. This avoids the need to do some unusual gymnastics to handle having to return aggregated and non-aggregated tuples from underlying nodes, as well as having to shut down underlying nodes early to limit memory usage. The optimizer still builds Sort/Agg node to describe each phase, but they're not part of the plan tree, but instead additional data for the aggregation node. They're a convenient and preexisting way to describe aggregation and sorting. The first (and possibly only) sort step is still performed as a separate execution step. That retains similarity with existing group by plans, makes rescans fairly simple, avoids very deep plans (leading to slow explains) and easily allows to avoid the sorting step if the underlying data is sorted by other means. A somewhat ugly side of this patch is having to deal with a grammar ambiguity between the new CUBE keyword and the cube extension/functions named cube (and rollup). To avoid breaking existing deployments of the cube extension it has not been renamed, neither has cube been made a reserved keyword. Instead precedence hacking is used to make GROUP BY cube(..) refer to the CUBE grouping sets feature, and not the function cube(). To actually group by a function cube(), unlikely as that might be, the function name has to be quoted. Needs a catversion bump because stored rules may change. Author: Andrew Gierth and Atri Sharma, with contributions from Andres Freund Reviewed-By: Andres Freund, Noah Misch, Tom Lane, Svenne Krap, Tomas Vondra, Erik Rijkers, Marti Raudsepp, Pavel Stehule Discussion: CAOeZVidmVRe2jU6aMk_5qkxnB7dfmPROzM7Ur8JPW5j8Y5X-Lw@mail.gmail.com
2015-05-15TABLESAMPLE, SQL Standard and extensibleSimon Riggs
Add a TABLESAMPLE clause to SELECT statements that allows user to specify random BERNOULLI sampling or block level SYSTEM sampling. Implementation allows for extensible sampling functions to be written, using a standard API. Basic version follows SQLStandard exactly. Usable concrete use cases for the sampling API follow in later commits. Petr Jelinek Reviewed by Michael Paquier and Simon Riggs
2015-05-11Replace some appendStringInfo* calls with more appropriate variantsPeter Eisentraut
Author: David Rowley <dgrowleyml@gmail.com>
2015-05-10Code review for foreign/custom join pushdown patch.Tom Lane
Commit e7cb7ee14555cc9c5773e2c102efd6371f6f2005 included some design decisions that seem pretty questionable to me, and there was quite a lot of stuff not to like about the documentation and comments. Clean up as follows: * Consider foreign joins only between foreign tables on the same server, rather than between any two foreign tables with the same underlying FDW handler function. In most if not all cases, the FDW would simply have had to apply the same-server restriction itself (far more expensively, both for lack of caching and because it would be repeated for each combination of input sub-joins), or else risk nasty bugs. Anyone who's really intent on doing something outside this restriction can always use the set_join_pathlist_hook. * Rename fdw_ps_tlist/custom_ps_tlist to fdw_scan_tlist/custom_scan_tlist to better reflect what they're for, and allow these custom scan tlists to be used even for base relations. * Change make_foreignscan() API to include passing the fdw_scan_tlist value, since the FDW is required to set that. Backwards compatibility doesn't seem like an adequate reason to expect FDWs to set it in some ad-hoc extra step, and anyway existing FDWs can just pass NIL. * Change the API of path-generating subroutines of add_paths_to_joinrel, and in particular that of GetForeignJoinPaths and set_join_pathlist_hook, so that various less-used parameters are passed in a struct rather than as separate parameter-list entries. The objective here is to reduce the probability that future additions to those parameter lists will result in source-level API breaks for users of these hooks. It's possible that this is even a small win for the core code, since most CPU architectures can't pass more than half a dozen parameters efficiently anyway. I kept root, joinrel, outerrel, innerrel, and jointype as separate parameters to reduce code churn in joinpath.c --- in particular, putting jointype into the struct would have been problematic because of the subroutines' habit of changing their local copies of that variable. * Avoid ad-hocery in ExecAssignScanProjectionInfo. It was probably all right for it to know about IndexOnlyScan, but if the list is to grow we should refactor the knowledge out to the callers. * Restore nodeForeignscan.c's previous use of the relcache to avoid extra GetFdwRoutine lookups for base-relation scans. * Lots of cleanup of documentation and missed comments. Re-order some code additions into more logical places.
2015-05-08Add support for INSERT ... ON CONFLICT DO NOTHING/UPDATE.Andres Freund
The newly added ON CONFLICT clause allows to specify an alternative to raising a unique or exclusion constraint violation error when inserting. ON CONFLICT refers to constraints that can either be specified using a inference clause (by specifying the columns of a unique constraint) or by naming a unique or exclusion constraint. DO NOTHING avoids the constraint violation, without touching the pre-existing row. DO UPDATE SET ... [WHERE ...] updates the pre-existing tuple, and has access to both the tuple proposed for insertion and the existing tuple; the optional WHERE clause can be used to prevent an update from being executed. The UPDATE SET and WHERE clauses have access to the tuple proposed for insertion using the "magic" EXCLUDED alias, and to the pre-existing tuple using the table name or its alias. This feature is often referred to as upsert. This is implemented using a new infrastructure called "speculative insertion". It is an optimistic variant of regular insertion that first does a pre-check for existing tuples and then attempts an insert. If a violating tuple was inserted concurrently, the speculatively inserted tuple is deleted and a new attempt is made. If the pre-check finds a matching tuple the alternative DO NOTHING or DO UPDATE action is taken. If the insertion succeeds without detecting a conflict, the tuple is deemed inserted. To handle the possible ambiguity between the excluded alias and a table named excluded, and for convenience with long relation names, INSERT INTO now can alias its target table. Bumps catversion as stored rules change. Author: Peter Geoghegan, with significant contributions from Heikki Linnakangas and Andres Freund. Testing infrastructure by Jeff Janes. Reviewed-By: Heikki Linnakangas, Andres Freund, Robert Haas, Simon Riggs, Dean Rasheed, Stephen Frost and many others.
2015-05-07Fix indentation that could mask a future bugMagnus Hagander
Michael Paquier, spotted using Coverity