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2008-05-27Back-patch the 8.3 fix that prohibits TRUNCATE, CLUSTER, and REINDEX when theTom Lane
current transaction has any open references to the target relation or index (implying it has an active query using the relation). Also back-patch the 8.2 fix that prohibits TRUNCATE and CLUSTER when there are pending AFTER-trigger events. Per suggestion from Heikki.
2008-05-09Fix an ancient oversight in change_varattnos_of_a_node: it neglected to updateTom Lane
varoattno along with varattno. This resulted in having Vars that were not seen as equal(), causing inheritance of the "same" constraint from different parent relations to fail. An example is create table pp1 (f1 int check (f1>0)); create table cc1 (f2 text, f3 int) inherits (pp1); create table cc2(f4 float) inherits(pp1,cc1); Backpatch as far as 7.4. (The test case still fails in 7.4, for reasons that I don't feel like investigating at the moment.) This is a backpatch commit only. The fix will be applied in HEAD as part of the upcoming pg_constraint patch.
2008-04-24Fix ALTER TABLE ADD COLUMN ... PRIMARY KEY so that the new column is correctlyTom Lane
checked to see if it's been initialized to all non-nulls. The implicit NOT NULL constraint was not being checked during the ALTER (in fact, not even if there was an explicit NOT NULL too), because ATExecAddColumn neglected to set the flag needed to make the test happen. This has been broken since the capability was first added, in 8.0. Brendan Jurd, per a report from Kaloyan Iliev.
2008-03-12Fix LISTEN/NOTIFY race condition reported by Laurent Birtz, by postponingTom Lane
pg_listener modifications commanded by LISTEN and UNLISTEN until the end of the current transaction. This allows us to hold the ExclusiveLock on pg_listener until after commit, with no greater risk of deadlock than there was before. Aside from fixing the race condition, this gets rid of a truly ugly kludge that was there before, namely having to ignore HeapTupleBeingUpdated failures during NOTIFY. There is a small potential incompatibility, which is that if a transaction issues LISTEN or UNLISTEN and then looks into pg_listener before committing, it won't see any resulting row insertion or deletion, where before it would have. It seems unlikely that anyone would be depending on that, though. This patch also disallows LISTEN and UNLISTEN inside a prepared transaction. That case had some pretty undesirable properties already, such as possibly allowing pg_listener entries to be made for PIDs no longer present, so disallowing it seems like a better idea than trying to maintain the behavior.
2008-02-11Repair VACUUM FULL bug introduced by HOT patch: the original way ofTom Lane
calculating a page's initial free space was fine, and should not have been "improved" by letting PageGetHeapFreeSpace do it. VACUUM FULL is going to reclaim LP_DEAD line pointers later, so there is no need for a guard against the page being too full of line pointers, and having one risks rejecting pages that are perfectly good move destinations. This also exposed a second bug, which is that the empty_end_pages logic assumed that any page with no live tuples would get entered into the fraged_pages list automatically (by virtue of having more free space than the threshold in the do_frag calculation). This assumption certainly seems risky when a low fillfactor has been chosen, and even without tunable fillfactor I think it could conceivably fail on a page with many unused line pointers. So fix the code to force do_frag true when notup is true, and patch this part of the fix all the way back. Per report from Tomas Szepe.
2008-02-07Some variants of ALTER OWNER tried to make the "object" field of theTom Lane
statement be a list of bare C strings, rather than String nodes, which is what they need to be for copyfuncs/equalfuncs to work. Fortunately these node types never go out to disk (if they did, we'd likely have noticed the problem sooner), so we can just fix it without creating a need for initdb. This bug has been there since 8.0, but 8.3 exposes it in a more common code path (Parse messages) than prior releases did. Per bug #3940 from Vladimir Kokovic.
2008-01-03Make standard maintenance operations (including VACUUM, ANALYZE, REINDEX,Tom Lane
and CLUSTER) execute as the table owner rather than the calling user, using the same privilege-switching mechanism already used for SECURITY DEFINER functions. The purpose of this change is to ensure that user-defined functions used in index definitions cannot acquire the privileges of a superuser account that is performing routine maintenance. While a function used in an index is supposed to be IMMUTABLE and thus not able to do anything very interesting, there are several easy ways around that restriction; and even if we could plug them all, there would remain a risk of reading sensitive information and broadcasting it through a covert channel such as CPU usage. To prevent bypassing this security measure, execution of SET SESSION AUTHORIZATION and SET ROLE is now forbidden within a SECURITY DEFINER context. Thanks to Itagaki Takahiro for reporting this vulnerability. Security: CVE-2007-6600
2007-09-24Reduce the size of memory allocations by lazy vacuum when processing a smallAlvaro Herrera
table, by allocating just enough for a hardcoded number of dead tuples per page. The current estimate is 200 dead tuples per page. Per reports from Jeff Amiel, Erik Jones and Marko Kreen, and subsequent discussion. CVS: ---------------------------------------------------------------------- CVS: Enter Log. Lines beginning with `CVS:' are removed automatically CVS: CVS: Committing in . CVS: CVS: Modified Files: CVS: commands/vacuumlazy.c CVS: ----------------------------------------------------------------------
2007-09-16Fix aboriginal mistake in lazy VACUUM's code for truncating awayTom Lane
no-longer-needed pages at the end of a table. We thought we could throw away pages containing HEAPTUPLE_DEAD tuples; but this is not so, because such tuples very likely have index entries pointing at them, and we wouldn't have removed the index entries. The problem only emerges in a somewhat unlikely race condition: the dead tuples have to have been inserted by a transaction that later aborted, and this has to have happened between VACUUM's initial scan of the page and then rechecking it for empty in count_nondeletable_pages. But that timespan will include an index-cleaning pass, so it's not all that hard to hit. This seems to explain a couple of previously unsolved bug reports.
2007-09-12Make REINDEX DATABASE silently skip remote temp tables.Alvaro Herrera
Per report from bitsandbytes88 <at> hotmail.com and subsequent discussion. This is a back patch of a patch committed yesterday to CLUSTER and REINDEX. REINDEX only processes user indexes as of 8.1, so we needn't backpatch this any further. (CLUSTER was backpatched separately all the way back to 7.4).
2007-09-12Fix the database-wide version of CLUSTER to silently skip temp tables ofAlvaro Herrera
remote sessions, instead of erroring out in the middle of the operation. This is a backpatch of a previous fix applied to CLUSTER to HEAD and 8.2, all the way back that it is relevant to.
2007-09-12Add a CHECK_FOR_INTERRUPTS call in the site where the vacuum delay pointAlvaro Herrera
was removed.
2007-09-10Remove the vacuum_delay_point call in count_nondeletable_pages, because we holdAlvaro Herrera
an exclusive lock on the table at this point, which we want to release as soon as possible. This is called in the phase of lazy vacuum where we truncate the empty pages at the end of the table. An alternative solution would be to lower the vacuum delay settings before starting the truncating phase, but this doesn't work very well in autovacuum due to the autobalancing code (which can cause other processes to change our cost delay settings). This case could be considered in the balancing code, but it is simpler this way.
2007-08-25Fix brain fade in DefineIndex(): it was continuing to access the table'sTom Lane
relcache entry after having heap_close'd it. This could lead to misbehavior if a relcache flush wiped out the cache entry meanwhile. In 8.2 there is a very real risk of CREATE INDEX CONCURRENTLY using the wrong relid for locking and waiting purposes. I think the bug is only cosmetic in 8.0 and 8.1, because their transgression is limited to using RelationGetRelationName(rel) in an ereport message immediately after heap_close, and there's no way (except with special debugging options) for a cache flush to occur in that interval. Not quite sure that it's cosmetic in 7.4, but seems best to patch anyway. Found by trying to run the regression tests with CLOBBER_CACHE_ALWAYS enabled. Maybe we should try to do that on a regular basis --- it's awfully slow, but perhaps some fast buildfarm machine could do it once in awhile.
2007-08-15Repair problems occurring when multiple RI updates have to be done to the sameTom Lane
row within one query: we were firing check triggers before all the updates were done, leading to bogus failures. Fix by making the triggers queued by an RI update go at the end of the outer query's trigger event list, thereby effectively making the processing "breadth-first". This was indeed how it worked pre-8.0, so the bug does not occur in the 7.x branches. Per report from Pavel Stehule.
2007-07-17Fix incorrect optimization of foreign-key checks. When an UPDATE on theTom Lane
referencing table does not change the tuple's FK column(s), we don't bother to check the PK table since the constraint was presumably already valid. However, the check is still necessary if the tuple was inserted by our own transaction, since in that case the INSERT trigger will conclude it need not make the check (since its version of the tuple has been deleted). We got this right for simple cases, but not when the insert and update are in different subtransactions of the current top-level transaction; in such cases the FK check would never be made at all. (Hence, problem dates back to 8.0 when subtransactions were added --- it's actually the subtransaction version of a bug fixed in 7.3.5.) Fix, and add regression test cases. Report and fix by Affan Salman.
2007-06-20CREATE DOMAIN ... DEFAULT NULL failed because gram.y special-cases DEFAULTTom Lane
NULL and DefineDomain didn't. Bug goes all the way back to original coding of domains. Per bug #3396 from Sergey Burladyan.
2007-06-14Avoid having autovacuum run multiple ANALYZE commands in a single transaction,Alvaro Herrera
to prevent possible deadlock problems. Per request from Tom Lane.
2007-04-12Cancel pending fsync requests during WAL replay of DROP DATABASE, per bugTom Lane
report from David Darville. Back-patch as far as 8.1, which may or may not have the problem but it seems a safe change anyway.
2007-03-14Fix a longstanding bug in VACUUM FULL's handling of update chains. The codeTom Lane
did not expect that a DEAD tuple could follow a RECENTLY_DEAD tuple in an update chain, but because the OldestXmin rule for determining deadness is a simplification of reality, it is possible for this situation to occur (implying that the RECENTLY_DEAD tuple is in fact dead to all observers, but this patch does not attempt to exploit that). The code would follow a chain forward all the way, but then stop before a DEAD tuple when backing up, meaning that not all of the chain got moved. This could lead to copying the chain multiple times (resulting in duplicate copies of the live tuple at its end), or leaving dangling index entries behind (which, aside from generating warnings from later vacuums, creates a risk of wrong query results or bogus duplicate-key errors once the heap slot the index entry points to is repopulated). The fix is to recheck HeapTupleSatisfiesVacuum while following a chain forward, and to stop if a DEAD tuple is reached. Each contiguous group of RECENTLY_DEAD tuples will therefore be copied as a separate chain. The patch also adds a couple of extra sanity checks to verify correct behavior. Per report and test case from Pavan Deolasee.
2007-02-06Fix an error in the original coding of holdable cursors: PersistHoldablePortalTom Lane
thought that it didn't have to reposition the underlying tuplestore if the portal is atEnd. But this is not so, because tuplestores have separate read and write cursors ... and the read cursor hasn't moved from the start. This mistake explains bug #2970 from William Zhang. Note: the coding here is pretty inefficient, but given that no one has noticed this bug until now, I'd say hardly anyone uses the case where the cursor has been advanced before being persisted. So maybe it's not worth worrying about.
2007-02-02Repair failure to check that a table is still compatible with a previouslyTom Lane
made query plan. Use of ALTER COLUMN TYPE creates a hazard for cached query plans: they could contain Vars that claim a column has a different type than it now has. Fix this by checking during plan startup that Vars at relation scan level match the current relation tuple descriptor. Since at that point we already have at least AccessShareLock, we can be sure the column type will not change underneath us later in the query. However, since a backend's locks do not conflict against itself, there is still a hole for an attacker to exploit: he could try to execute ALTER COLUMN TYPE while a query is in progress in the current backend. Seal that hole by rejecting ALTER TABLE whenever the target relation is already open in the current backend. This is a significant security hole: not only can one trivially crash the backend, but with appropriate misuse of pass-by-reference datatypes it is possible to read out arbitrary locations in the server process's memory, which could allow retrieving database content the user should not be able to see. Our thanks to Jeff Trout for the initial report. Security: CVE-2007-0556
2007-01-27Back-port changes of Jan 16 and 17 to "revoke" pending fsync requests duringTom Lane
DROP TABLE and DROP DATABASE. Should prevent unexpected "permission denied" failures on Windows, and is cleaner on other platforms too since we no longer have to take it on faith that ENOENT is okay during an fsync attempt. Patched as far back as 8.1; per recent discussion I think we are not going to worry about Windows-specific issues in 8.0 anymore.
2006-07-10Fix ALTER TABLE to check pre-existing NOT NULL constraints when rewritingTom Lane
a table. Otherwise a USING clause that yields NULL can leave the table violating its constraint (possibly there are other cases too). Per report from Alexander Pravking.
2006-05-21Change the backend to reject strings containing invalidly-encoded multibyteTom Lane
characters in all cases. Formerly we mostly just threw warnings for invalid input, and failed to detect it at all if no encoding conversion was required. The tighter check is needed to defend against SQL-injection attacks as per CVE-2006-2313 (further details will be published after release). Embedded zero (null) bytes will be rejected as well. The checks are applied during input to the backend (receipt from client or COPY IN), so it no longer seems necessary to check in textin() and related routines; any string arriving at those functions will already have been validated. Conversion failure reporting (for characters with no equivalent in the destination encoding) has been cleaned up and made consistent while at it. Also, fix a few longstanding errors in little-used encoding conversion routines: win1251_to_iso, win866_to_iso, euc_tw_to_big5, euc_tw_to_mic, mic_to_euc_tw were all broken to varying extents. Patches by Tatsuo Ishii and Tom Lane. Thanks to Akio Ishida and Yasuo Ohgaki for identifying the security issues.
2006-03-29TablespaceCreateDbspace should function normally even on platforms that do notTom Lane
have symlinks (ie, Windows). Although it'll never be called on to do anything useful during normal operation on such a platform, it's still needed to re-create dropped directories during WAL replay.
2006-03-04Prevent lazy_space_alloc from making requests that exceed MaxAllocSize,Tom Lane
per report from Stefan Kaltenbrunner.
2006-02-12Fix bug that allowed any logged-in user to SET ROLE to any other database userTom Lane
id (CVE-2006-0553). Also fix related bug in SET SESSION AUTHORIZATION that allows unprivileged users to crash the server, if it has been compiled with Asserts enabled. The escalation-of-privilege risk exists only in 8.1.0-8.1.2. However, the Assert-crash risk exists in all releases back to 7.3. Thanks to Akio Ishida for reporting this problem.
2006-02-10Change search for default operator classes so that it examines all opclassesTom Lane
regardless of the current schema search path. Since CREATE OPERATOR CLASS only allows one default opclass per datatype regardless of schemas, this should have minimal impact, and it fixes problems with failure to find a desired opclass while restoring dump files. Per discussion at http://archives.postgresql.org/pgsql-hackers/2006-02/msg00284.php. Remove now-redundant-or-unused code in typcache.c and namespace.c, and backpatch as far as 8.0.
2006-01-30Fix ALTER COLUMN TYPE bug: it sometimes tried to drop UNIQUE or PRIMARY KEYTom Lane
constraints before FOREIGN KEY constraints that depended on them. Originally reported by Neil Conway on 29-Jun-2005. Patch by Nakano Yoshihisa.
2006-01-19It turns out that TablespaceCreateDbspace fails badly if a relcache flushTom Lane
occurs when it tries to heap_open pg_tablespace. When control returns to smgrcreate, that routine will be holding a dangling pointer to a closed SMgrRelation, resulting in mayhem. This is of course a consequence of the violation of proper module layering inherent in having smgr.c call a tablespace command routine, but the simplest fix seems to be to change the locking mechanism. There's no real need for TablespaceCreateDbspace to touch pg_tablespace at all --- it's only opening it as a way of locking against a parallel DROP TABLESPACE command. A much better answer is to create a special-purpose LWLock to interlock these two operations. This drops TablespaceCreateDbspace quite a few layers down the food chain and makes it something reasonably safe for smgr to call.
2006-01-18Modify pgstats code to reduce performance penalties from oversized stats dataTom Lane
files: avoid creating stats hashtable entries for tables that aren't being touched except by vacuum/analyze, ensure that entries for dropped tables are removed promptly, and tweak the data layout to avoid storing useless struct padding. Also improve the performance of pgstat_vacuum_tabstat(), and make sure that autovacuum invokes it exactly once per autovac cycle rather than multiple times or not at all. This should cure recent complaints about 8.1 showing much higher stats I/O volume than was seen in 8.0. It'd still be a good idea to revisit the design with an eye to not re-writing the entire stats dataset every half second ... but that would be too much to backpatch, I fear.
2006-01-12Repair "Halloween problem" in EvalPlanQual: a tuple that's been inserted byTom Lane
our own command (or more generally, xmin = our xact and cmin >= current command ID) should not be seen as good. Else we may try to update rows we already updated. This error was inserted last August while fixing the even bigger problem that the old coding wouldn't see *any* tuples inserted by our own transaction as good. Per report from Euler Taveira de Oliveira.
2006-01-04Fix another case in which autovacuum would fail while analyzingTom Lane
expressional indexes. Per report from Brian Hirt.
2005-12-28Add regression tests for CSV and \., and add automatic quoting of aBruce Momjian
single column dump that has a \. value, so the load works properly. I also added documentation describing this issue. Backpatch to 8.1.X.
2005-12-27Our code had:Bruce Momjian
if (c == '\\' && cstate->line_buf.len == 0) The problem with that is the because of the input and _output_ buffering, cstate->line_buf.len could be zero even if we are not on the first character of a line. In fact, for a typical line, it is zero for all characters on the line. The proper solution is to introduce a boolean, first_char_in_line, that we set as we enter the loop and clear once we process a character. I have restructured the line-reading code in copy.c by: o merging the CSV/non-CSV functions into a single function o used macros to centralize and clarify the buffering code o updated comments o renamed client_encoding_only to encoding_embeds_ascii o added a high-bit test to the encoding_embeds_ascii test for performance o in CSV mode, allow a backslash followed by a non-period to continue being processed as a data value There should be no performance impact from this patch because it is functionally equivalent. If you apply the patch you will see copy.c is much clearer in this area now and might suggest additional optimizations. I have also attached a 8.1-only patch to fix the CSV \. handling bug with no code restructuring.
2005-12-14Defend against crash while processing Describe Statement or Describe PortalTom Lane
messages, when client attempts to execute these outside a transaction (start one) or in a failed transaction (reject message, except for COMMIT/ROLLBACK statements which we can handle). Per report from Francisco Figueiredo Jr.
2005-11-22Re-run pgindent, fixing a problem where comment lines after a blankBruce Momjian
comment line where output as too long, and update typedefs for /lib directory. Also fix case where identifiers were used as variable names in the backend, but as typedefs in ecpg (favor the backend for indenting). Backpatch to 8.1.X.
2005-11-04Disregard superuserness when checking to see if a role GRANT wouldTom Lane
create circularity of role memberships. This is a minimum-impact fix for the problem reported by Florian Pflug. I thought about removing the superuser_arg test from is_member_of_role() altogether, as it seems redundant for many of the callers --- but not all, and it's way too late in the 8.1 cycle to be making large changes. Perhaps reconsider this later.
2005-11-03Rename the members of CommandDest enum so they don't collide with other uses ofAlvaro Herrera
those names. (Debug and None were pretty bad names anyway.) I hope I catched all uses of the names in comments too.
2005-10-29Message correctionsPeter Eisentraut
2005-10-21Fix EXPLAIN ANALYZE bug noted by Wiebe Cazemier: although we wereTom Lane
properly advancing the CommandCounter between multiple sub-queries generated by rules, we forgot to update the snapshot being used, so that the successive sub-queries didn't actually see each others' results. This is still not *exactly* like the semantics of normal execution of the same queries, in that we don't take new transaction snapshots and hence don't see changes from concurrently committed commands, but I think that's OK and probably even preferable for EXPLAIN ANALYZE.
2005-10-18A few trivial code cleanups motivated by reading warnings generatedTom Lane
by a recent HP C compiler. Mostly, get rid of useless local variables that are assigned to but never used.
2005-10-17Clean up libpq's pollution of application namespace by renaming theTom Lane
exported routines of ip.c, md5.c, and fe-auth.c to begin with 'pg_'. Also get rid of the vestigial fe_setauthsvc/fe_getauthsvc routines altogether.
2005-10-15Standard pgindent run for 8.1.Bruce Momjian
2005-10-10Use a safer order of operations in dropdb(): rollbackable operations,Tom Lane
ie removing shared-dependency entries, should happen before non-rollbackable ones. That way a failure during the rollbackable part doesn't leave us with inconsistent state.
2005-10-06Minor API cleanup for async notifications: we can only register theNeil Conway
current backend in pg_listener, so there is little point in making the PID to register part of async.c's public API. Other minor tweaks.
2005-10-03COPY's test for read-only transaction was backward; it prohibited COPY TOTom Lane
where it should prohibit COPY FROM. Found by Alon Goldshuv.
2005-10-03Separate out the VacRUsage stuff as an independent module, in preparationTom Lane
for using it for other things besides VACUUM.
2005-10-03Preserve tuple OIDs during ATRewriteTable. Per gripe from Duncan Crombie.Tom Lane