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2016-06-16Fix validation of overly-long IPv6 addresses.Tom Lane
The inet/cidr types sometimes failed to reject IPv6 inputs with too many colon-separated fields, instead translating them to '::/0'. This is the result of a thinko in the original ISC code that seems to be as yet unreported elsewhere. Per bug #14198 from Stefan Kaltenbrunner. Report: <20160616182222.5798.959@wrigleys.postgresql.org>
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>
2016-05-06Fix possible read past end of string in to_timestamp().Tom Lane
to_timestamp() handles the TH/th format codes by advancing over two input characters, whatever those are. It failed to notice whether there were two characters available to be skipped, making it possible to advance the pointer past the end of the input string and keep on parsing. A similar risk existed in the handling of "Y,YYY" format: it would advance over three characters after the "," whether or not three characters were available. In principle this might be exploitable to disclose contents of server memory. But the security team concluded that it would be very hard to use that way, because the parsing loop would stop upon hitting any zero byte, and TH/th format codes can't be consecutive --- they have to follow some other format code, which would have to match whatever data is there. So it seems impractical to examine memory very much beyond the end of the input string via this bug; and the input string will always be in local memory not in disk buffers, making it unlikely that anything very interesting is close to it in a predictable way. So this doesn't quite rise to the level of needing a CVE. Thanks to Wolf Roediger for reporting this bug.
2016-04-23Rename strtoi() to strtoint().Tom Lane
NetBSD has seen fit to invent a libc function named strtoi(), which conflicts with the long-established static functions of the same name in datetime.c and ecpg's interval.c. While muttering darkly about intrusions on application namespace, we'll rename our functions to avoid the conflict. Back-patch to all supported branches, since this would affect attempts to build any of them on recent NetBSD. Thomas Munro
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>
2016-03-23Disable abbreviated keys for string-sorting in non-C locales.Robert Haas
Unfortunately, every version of glibc thus far tested has bugs whereby strcoll() ordering does not match strxfrm() ordering as required by the standard. This can result in, for example, corrupted indexes. Disabling abbreviated keys in these cases slows down non-C-collation string sorting considerably, but there seems to be no practical alternative. Users who are confident that their libc implementations are solid in this regard can re-enable the optimization by compiling with TRUST_STRXFRM. Users who have built indexes using PostgreSQL 9.5 or PostgreSQL 9.5.1 should REINDEX if there is a possibility that they may have been affected by this problem. Report by Marc-Olaf Jaschke. Investigation mostly by Tom Lane, with help from Peter Geoghegan, Noah Misch, Stephen Frost, and me. Patch by me, reviewed by Peter Geoghegan and Tom Lane.
2016-03-23Code review for error reports in jsonb_set().Tom Lane
User-facing (even tested by regression tests) error conditions were thrown with elog(), hence had wrong SQLSTATE and were untranslatable. And the error message texts weren't up to project style, either.
2016-03-23Fix unsafe use of strtol() on a non-null-terminated Text datum.Tom Lane
jsonb_set() could produce wrong answers or incorrect error reports, or in the worst case even crash, when trying to convert a path-array element into an integer for use as an array subscript. Per report from Vitaly Burovoy. Back-patch to 9.5 where the faulty code was introduced (in commit c6947010ceb42143). Michael Paquier
2016-03-17Fix assorted breakage in to_char()'s OF format option.Tom Lane
In HEAD, fix incorrect field width for hours part of OF when tm_gmtoff is negative. This was introduced by commit 2d87eedc1d4468d3 as a result of falsely applying a pattern that's correct when + signs are omitted, which is not the case for OF. In 9.4, fix missing abs() call that allowed a sign to be attached to the minutes part of OF. This was fixed in 9.5 by 9b43d73b3f9bef27, but for inscrutable reasons not back-patched. In all three versions, ensure that the sign of tm_gmtoff is correctly reported even when the GMT offset is less than 1 hour. Add regression tests, which evidently we desperately need here. Thomas Munro and Tom Lane, per report from David Fetter
2016-03-02Fix json_to_record() bug with nested objects.Tom Lane
A thinko concerning nesting depth caused json_to_record() to produce bogus output if a field of its input object contained a sub-object with a field name matching one of the requested output column names. Per bug #13996 from Johann Visagie. I added a regression test case based on his example, plus parallel tests for json_to_recordset, jsonb_to_record, jsonb_to_recordset. The latter three do not exhibit the same bug (which suggests that we may be missing some opportunities to share code...) but testing seems like a good idea in any case. Back-patch to 9.4 where these functions were introduced.
2016-02-28Avoid multiple free_struct_lconv() calls on same data.Tom Lane
A failure partway through PGLC_localeconv() led to a situation where the next call would call free_struct_lconv() a second time, leading to free() on already-freed strings, typically leading to a core dump. Add a flag to remember whether we need to do that. Per report from Thom Brown. His example case only provokes the failure as far back as 9.4, but nonetheless this code is obviously broken, so back-patch to all supported branches.
2016-02-21Fix two-argument jsonb_object when called with empty arraysAndrew Dunstan
Some over-eager copy-and-pasting on my part resulted in a nonsense result being returned in this case. I have adopted the same pattern for handling this case as is used in the one argument form of the function, i.e. we just skip over the code that adds values to the object. Diagnosis and patch from Michael Paquier, although not quite his solution. Fixes bug #13936. Backpatch to 9.5 where jsonb_object was introduced.
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
2016-02-03Fix IsValidJsonNumber() to notice trailing non-alphanumeric garbage.Tom Lane
Commit e09996ff8dee3f70 was one brick shy of a load: it didn't insist that the detected JSON number be the whole of the supplied string. This allowed inputs such as "2016-01-01" to be misdetected as valid JSON numbers. Per bug #13906 from Dmitry Ryabov. In passing, be more wary of zero-length input (I'm not sure this can happen given current callers, but better safe than sorry), and do some minor cosmetic cleanup.
2016-01-22Remove new coupling between NAMEDATALEN and MAX_LEVENSHTEIN_STRLEN.Tom Lane
Commit e529cd4ffa605c6f introduced an Assert requiring NAMEDATALEN to be less than MAX_LEVENSHTEIN_STRLEN, which has been 255 for a long time. Since up to that instant we had always allowed NAMEDATALEN to be substantially more than that, this was ill-advised. It's debatable whether we need MAX_LEVENSHTEIN_STRLEN at all (versus putting a CHECK_FOR_INTERRUPTS into the loop), or whether it has to be so tight; but this patch takes the narrower approach of just not applying the MAX_LEVENSHTEIN_STRLEN limit to calls from the parser. Trusting the parser for this seems reasonable, first because the strings are limited to NAMEDATALEN which is unlikely to be hugely more than 256, and second because the maximum distance is tightly constrained by MAX_FUZZY_DISTANCE (though we'd forgotten to make use of that limit in one place). That means the cost is not really O(mn) but more like O(max(m,n)). Relaxing the limit for user-supplied calls is left for future research; given the lack of complaints to date, it doesn't seem very high priority. In passing, fix confusion between lengths-in-bytes and lengths-in-chars in comments and error messages. Per gripe from Kevin Day; solution suggested by Robert Haas. Back-patch to 9.5 where the unwanted restriction was introduced.
2016-01-09Remove a useless PG_GETARG_DATUM() call from jsonb_build_array.Tom Lane
This loop uselessly fetched the argument after the one it's currently looking at. No real harm is done since we couldn't possibly fetch off the end of memory, but it's confusing to the reader. Also remove a duplicate (and therefore confusing) PG_ARGISNULL check in jsonb_build_object. I happened to notice these things while trolling for missed null-arg checks earlier today. Back-patch to 9.5, not because there is any real bug, but just because 9.5 and HEAD are still in sync in this file and we might as well keep them so. In passing, re-pgindent.
2016-01-04Fix regrole and regnamespace output functions to do quoting, too.Tom Lane
We discussed this but somehow failed to implement it...
2016-01-04Fix regrole and regnamespace types to honor quoting like other reg* types.Tom Lane
Aside from any consistency arguments, this is logically necessary because the I/O functions for these types also handle numeric OID values. Without a quoting rule it is impossible to distinguish numeric OIDs from role or namespace names that happen to contain only digits. Also change the to_regrole and to_regnamespace functions to dequote their arguments. While not logically essential, this seems like a good idea since the other to_reg* functions do it. Anyone who really wants raw lookup of an uninterpreted name can fall back on the time-honored solution of (SELECT oid FROM pg_namespace WHERE nspname = whatever). Report and patch by Jim Nasby, reviewed by Michael Paquier
2016-01-03Guard against null arguments in binary_upgrade_create_empty_extension().Tom Lane
The CHECK_IS_BINARY_UPGRADE macro is not sufficient security protection if we're going to dereference pass-by-reference arguments before it. But in any case we really need to explicitly check PG_ARGISNULL for all the arguments of a non-strict function, not only the ones we expect null values for. Oversight in commits 30982be4e5019684e1772dd9170aaa53f5a8e894 and f92fc4c95ddcc25978354a8248d3df22269201bc. Found by Andreas Seltenreich. (The other usages in pg_upgrade_support.c seem safe.)
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
2016-01-01Add some more defenses against silly estimates to gincostestimate().Tom Lane
A report from Andy Colson showed that gincostestimate() was not being nearly paranoid enough about whether to believe the statistics it finds in the index metapage. The problem is that the metapage stats (other than the pending-pages count) are only updated by VACUUM, and in the worst case could still reflect the index's original empty state even when it has grown to many entries. We attempted to deal with that by scaling up the stats to match the current index size, but if nEntries is zero then scaling it up still gives zero. Moreover, the proportion of pages that are entry pages vs. data pages vs. pending pages is unlikely to be estimated very well by scaling if the index is now orders of magnitude larger than before. We can improve matters by expanding the use of the rule-of-thumb estimates I introduced in commit 7fb008c5ee59b040: if the index has grown by more than a cutoff amount (here set at 4X growth) since VACUUM, then use the rule-of-thumb numbers instead of scaling. This might not be exactly right but it seems much less likely to produce insane estimates. I also improved both the scaling estimate and the rule-of-thumb estimate to account for numPendingPages, since it's reasonable to expect that that is accurate in any case, and certainly pages that are in the pending list are not either entry or data pages. As a somewhat separate issue, adjust the estimation equations that are concerned with extra fetches for partial-match searches. These equations suppose that a fraction partialEntries / numEntries of the entry and data pages will be visited as a consequence of a partial-match search. Now, it's physically impossible for that fraction to exceed one, but our estimate of partialEntries is mostly bunk, and our estimate of numEntries isn't exactly gospel either, so we could arrive at a silly value. In the example presented by Andy we were coming out with a value of 100, leading to insane cost estimates. Clamp the fraction to one to avoid that. Like the previous patch, back-patch to all supported branches; this problem can be demonstrated in one form or another in all of them.
2015-12-14Add missing CHECK_FOR_INTERRUPTS in lseg_inside_polyAlvaro Herrera
Apparently, there are bugs in this code that cause it to loop endlessly. That bug still needs more research, but in the meantime it's clear that the loop is missing a check for interrupts so that it can be cancelled timely. Backpatch to 9.1 -- this has been missing since 49475aab8d0d.
2015-12-10Improve some messagesPeter Eisentraut
2015-12-01Make gincostestimate() cope with hypothetical GIN indexes.Tom Lane
We tried to fetch statistics data from the index metapage, which does not work if the index isn't actually present. If the index is hypothetical, instead extrapolate some plausible internal statistics based on the index page count provided by the index-advisor plugin. There was already some code in gincostestimate() to invent internal stats in this way, but since it was only meant as a stopgap for pre-9.1 GIN indexes that hadn't been vacuumed since upgrading, it was pretty crude. If we want it to support index advisors, we should try a little harder. A small amount of testing says that it's better to estimate the entry pages as 90% of the index, not 100%. Also, estimating the number of entries (keys) as equal to the heap tuple count could be wildly wrong in either direction. Instead, let's estimate 100 entries per entry page. Perhaps someday somebody will want the index advisor to be able to provide these numbers more directly, but for the moment this should serve. Problem report and initial patch by Julien Rouhaud; modified by me to invent less-bogus internal statistics. Back-patch to all supported branches, since we've supported index advisors since 9.0.
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.
2015-11-17Fix possible internal overflow in numeric division.Tom Lane
div_var_fast() postpones propagating carries in the same way as mul_var(), so it has the same corner-case overflow risk we fixed in 246693e5ae8a36f0, namely that the size of the carries has to be accounted for when setting the threshold for executing a carry propagation step. We've not devised a test case illustrating the brokenness, but the required fix seems clear enough. Like the previous fix, back-patch to all active branches. Dean Rasheed
2015-11-16Message improvementsPeter Eisentraut
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.
2015-11-05Fix erroneous hash calculations in gin_extract_jsonb_path().Tom Lane
The jsonb_path_ops code calculated hash values inconsistently in some cases involving nested arrays and objects. This would result in queries possibly not finding entries that they should find, when using a jsonb_path_ops GIN index for the search. The problem cases involve JSONB values that contain both scalars and sub-objects at the same nesting level, for example an array containing both scalars and sub-arrays. To fix, reset the current stack->hash after processing each value or sub-object, not before; and don't try to be cute about the outermost level's initial hash. Correcting this means that existing jsonb_path_ops indexes may now be inconsistent with the new hash calculation code. The symptom is the same --- searches not finding entries they should find --- but the specific rows affected are likely to be different. Users will need to REINDEX jsonb_path_ops indexes to make sure that all searches work as expected. Per bug #13756 from Daniel Cheng. Back-patch to 9.4 where the faulty logic was introduced.
2015-10-28Message style improvementsPeter Eisentraut
Message style, plurals, quoting, spelling, consistency with similar messages
2015-10-20Fix incorrect translation of minus-infinity datetimes for json/jsonb.Tom Lane
Commit bda76c1c8cfb1d11751ba6be88f0242850481733 caused both plus and minus infinity to be rendered as "infinity", which is not only wrong but inconsistent with the pre-9.4 behavior of to_json(). Fix that by duplicating the coding in date_out/timestamp_out/timestamptz_out more closely. Per bug #13687 from Stepan Perlov. Back-patch to 9.4, like the previous commit. In passing, also re-pgindent json.c, since it had gotten a bit messed up by recent patches (and I was already annoyed by indentation-related problems in back-patching this fix ...)
2015-10-15Fix NULL handling in datum_to_jsonb().Tom Lane
The function failed to adhere to its specification that the "tcategory" argument should not be examined when the input value is NULL. This resulted in a crash in some cases. Per bug #13680 from Boyko Yordanov. In passing, re-pgindent some recent changes in jsonb.c, and fix a rather ungrammatical comment. Diagnosis and patch by Michael Paquier, cosmetic changes by me
2015-10-12Use JsonbIteratorToken consistently in automatic variable declarations.Noah Misch
Many functions stored JsonbIteratorToken values in variables of other integer types. Also, standardize order relative to other declarations. Expect compilers to generate the same code before and after this change.
2015-10-05Prevent stack overflow in query-type functions.Noah Misch
The tsquery, ltxtquery and query_int data types have a common ancestor. Having acquired check_stack_depth() calls independently, each was missing at least one call. Back-patch to 9.0 (all supported versions).
2015-10-05Prevent stack overflow in container-type functions.Noah Misch
A range type can name another range type as its subtype, and a record type can bear a column of another record type. Consequently, functions like range_cmp() and record_recv() are recursive. Functions at risk include operator family members and referents of pg_type regproc columns. Treat as recursive any such function that looks up and calls the same-purpose function for a record column type or the range subtype. Back-patch to 9.0 (all supported versions). An array type's element type is never itself an array type, so array functions are unaffected. Recursion depth proportional to array dimensionality, found in array_dim_to_jsonb(), is fine thanks to MAXDIM.
2015-10-05Prevent stack overflow in json-related functions.Noah Misch
Sufficiently-deep recursion heretofore elicited a SIGSEGV. If an application constructs PostgreSQL json or jsonb values from arbitrary user input, application users could have exploited this to terminate all active database connections. That applies to 9.3, where the json parser adopted recursive descent, and later versions. Only row_to_json() and array_to_json() were at risk in 9.2, both in a non-security capacity. Back-patch to 9.2, where the json type was introduced. Oskari Saarenmaa, reviewed by Michael Paquier. Security: CVE-2015-5289
2015-10-04ALTER TABLE .. FORCE ROW LEVEL SECURITYStephen Frost
To allow users to force RLS to always be applied, even for table owners, add ALTER TABLE .. FORCE ROW LEVEL SECURITY. row_security=off overrides FORCE ROW LEVEL SECURITY, to ensure pg_dump output is complete (by default). Also add SECURITY_NOFORCE_RLS context to avoid data corruption when ALTER TABLE .. FORCE ROW SECURITY is being used. The SECURITY_NOFORCE_RLS security context is used only during referential integrity checks and is only considered in check_enable_rls() after we have already checked that the current user is the owner of the relation (which should always be the case during referential integrity checks). Back-patch to 9.5 where RLS was added.
2015-10-04Disallow invalid path elements in jsonb_setAndrew Dunstan
Null path elements and, where the object is an array, invalid integer elements now cause an error. Incorrect behaviour noted by Thom Brown, patch from Dmitry Dolgov. Backpatch to 9.5 where jsonb_set was introduced
2015-10-02Add recursion depth protection to LIKE matching.Tom Lane
Since MatchText() recurses, it could in principle be driven to stack overflow, although quite a long pattern would be needed.
2015-09-25Second try at fixing O(N^2) problem in foreign key references.Tom Lane
This replaces ill-fated commit 5ddc72887a012f6a8b85707ef27d85c274faf53d, which was reverted because it broke active uses of FK cache entries. In this patch, we still do nothing more to invalidatable cache entries than mark them as needing revalidation, so we won't break active uses. To keep down the overhead of InvalidateConstraintCacheCallBack(), keep a list of just the currently-valid cache entries. (The entries are large enough that some added space for list links doesn't seem like a big problem.) This would still be O(N^2) when there are many valid entries, though, so when the list gets too long, just force the "sinval reset" behavior to remove everything from the list. I set the threshold at 1000 entries, somewhat arbitrarily. Possibly that could be fine-tuned later. Another item for future study is whether it's worth adding reference counting so that we could safely remove invalidated entries. As-is, problem cases are likely to end up with large and mostly invalid FK caches. Like the previous attempt, backpatch to 9.3. Jan Wieck and Tom Lane
2015-09-24Allow planner to use expression-index stats for function calls in WHERE.Tom Lane
Previously, a function call appearing at the top level of WHERE had a hard-wired selectivity estimate of 0.3333333, a kludge conveniently dated in the source code itself to July 1992. The expectation at the time was that somebody would soon implement estimator support functions analogous to those for operators; but no such code has appeared, nor does it seem likely to in the near future. We do have an alternative solution though, at least for immutable functions on single relations: creating an expression index on the function call will allow ANALYZE to gather stats about the function's selectivity. But the code in clause_selectivity() failed to make use of such data even if it exists. Refactor so that that will happen. I chose to make it try this technique for any clause type for which clause_selectivity() doesn't have a special case, not just functions. To avoid adding unnecessary overhead in the common case where we don't learn anything new, make selfuncs.c provide an API that hooks directly to examine_variable() and then var_eq_const(), rather than the previous coding which laboriously constructed an OpExpr only so that it could be expensively deconstructed again. I preserved the behavior that the default estimate for a function call is 0.3333333. (For any other expression node type, it's 0.5, as before.) I had originally thought to make the default be 0.5 across the board, but changing a default estimate that's survived for twenty-three years seems like something not to do without a lot more testing than I care to put into it right now. Per a complaint from Jehan-Guillaume de Rorthais. Back-patch into 9.5, but not further, at least for the moment.
2015-09-21Fix possible internal overflow in numeric multiplication.Tom Lane
mul_var() postpones propagating carries until it risks overflow in its internal digit array. However, the logic failed to account for the possibility of overflow in the carry propagation step, allowing wrong results to be generated in corner cases. We must slightly reduce the when-to-propagate-carries threshold to avoid that. Discovered and fixed by Dean Rasheed, with small adjustments by me. This has been wrong since commit d72f6c75038d8d37e64a29a04b911f728044d83b, so back-patch to all supported branches.
2015-09-20Remove the SECURITY_ROW_LEVEL_DISABLED security context bit.Noah Misch
This commit's parent made superfluous the bit's sole usage. Referential integrity checks have long run as the subject table's owner, and that now implies RLS bypass. Safe use of the bit was tricky, requiring strict control over the SQL expressions evaluating therein. Back-patch to 9.5, where the bit was introduced. Based on a patch by Stephen Frost.
2015-09-18Cache argument type information in json(b) aggregate functions.Andrew Dunstan
These functions have been looking up type info for every row they process. Instead of doing that we only look them up the first time through and stash the information in the aggregate state object. Affects json_agg, json_object_agg, jsonb_agg and jsonb_object_agg. There is plenty more work to do in making these more efficient, especially the jsonb functions, but this is a virtually cost free improvement that can be done right away. Backpatch to 9.5 where the jsonb variants were introduced.
2015-09-15Revert "Fix an O(N^2) problem in foreign key references".Tom Lane
Commit 5ddc72887a012f6a8b85707ef27d85c274faf53d does not actually work because it will happily blow away ri_constraint_cache entries that are in active use in outer call levels. In any case, it's a very ugly, brute-force solution to the problem of limiting the cache size. Revert until it can be redesigned.
2015-09-13Fix the fastpath rule for jsonb_concat with an empty operand.Andrew Dunstan
To prevent perverse results, we now only return the other operand if it's not scalar, and if both operands are of the same kind (array or object). Original bug complaint and patch from Oskari Saarenmaa, extended by me to cover the cases of different kinds of jsonb. Backpatch to 9.5 where jsonb_concat was introduced.
2015-09-11Fix an O(N^2) problem in foreign key references.Kevin Grittner
Commit 45ba424f improved foreign key lookups during bulk updates when the FK value does not change. When restoring a schema dump from a database with many (say 100,000) foreign keys, this cache would grow very big and every ALTER TABLE command was causing an InvalidateConstraintCacheCallBack(), which uses a sequential hash table scan. This could cause a severe performance regression in restoring a schema dump (including during pg_upgrade). The patch uses a heuristic method of detecting when the hash table should be destroyed and recreated. InvalidateConstraintCacheCallBack() adds the current size of the hash table to a counter. When that sum reaches 1,000,000, the hash table is flushed. This fixes the regression without noticeable harm to the bulk update use case. Jan Wieck Backpatch to 9.3 where the performance regression was introduced.
2015-09-06Move DTK_ISODOW DTK_DOW and DTK_DOY to be type UNITS rather thanGreg Stark
RESERV. RESERV is meant for tokens like "now" and having them in that category throws errors like these when used as an input date: stark=# SELECT 'doy'::timestamptz; ERROR: unexpected dtype 33 while parsing timestamptz "doy" LINE 1: SELECT 'doy'::timestamptz; ^ stark=# SELECT 'dow'::timestamptz; ERROR: unexpected dtype 32 while parsing timestamptz "dow" LINE 1: SELECT 'dow'::timestamptz; ^ Found by LLVM's Libfuzzer
2015-09-05Fix misc typos.Heikki Linnakangas
Oskari Saarenmaa. Backpatch to stable branches where applicable.