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* Repair PANIC condition in hash indexes when a previous index extension attemptTom Lane2007-04-19
| | | | | | | | | | | failed (due to lock conflicts or out-of-space). We might have already extended the index's filesystem EOF before failing, causing the EOF to be beyond what the metapage says is the last used page. Hence the invariant maintained by the code needs to be "EOF is at or beyond last used page", not "EOF is exactly the last used page". Problem was created by my patch of 2006-11-19 that attempted to repair bug #2737. Since that was back-patched to 7.4, this needs to be as well. Per report and test case from Vlastimil Krejcir.
* Translation updatesPeter Eisentraut2007-04-18
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* Rewrite choose_bitmap_and() to make it more robust in the presence ofTom Lane2007-04-17
| | | | | | | | | | | | | | | | | | competing alternatives for indexes to use in a bitmap scan. The former coding took estimated selectivity as an overriding factor, causing it to sometimes choose indexes that were much slower to scan than ones with a slightly worse selectivity. It was also too narrow-minded about which combinations of indexes to consider ANDing. The rewrite makes it pay more attention to index scan cost than selectivity; this seems sane since it's impossible to have very bad selectivity with low cost, whereas the reverse isn't true. Also, we now consider each index alone, as well as adding each index to an AND-group led by each prior index, for a total of about O(N^2) rather than O(N) combinations considered. This makes the results much less dependent on the exact order in which the indexes are considered. It's still a lot cheaper than an O(2^N) exhaustive search. A prefilter step eliminates all but the cheapest of those indexes using the same set of WHERE conditions, to keep the effective value of N down in scenarios where the DBA has created lots of partially-redundant indexes.
* Rearrange mdsync() looping logic to avoid the problem that a sufficientlyTom Lane2007-04-12
| | | | | | | | | | | fast flow of new fsync requests can prevent mdsync() from ever completing. This was an unforeseen consequence of a patch added in Mar 2006 to prevent the fsync request queue from overflowing. Problem identified by Heikki Linnakangas and independently by ITAGAKI Takahiro; fix based on ideas from Takahiro-san, Heikki, and Tom. Back-patch as far as 8.1 because a previous back-patch introduced the problem into 8.1 ...
* Cancel pending fsync requests during WAL replay of DROP DATABASE, per bugTom Lane2007-04-12
| | | | | 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.
* Fix check_sql_fn_retval to allow the case where a SQL function declared toTom Lane2007-04-02
| | | | | | | | return void ends with a SELECT, if that SELECT has a single result that is also of type void. Without this, it's hard to write a void function that calls another void function. Per gripe from Peter. Back-patch as far as 8.0.
* Fix oversight in coding of _bt_start_vacuum: we can't assume that the LWLockTom Lane2007-03-30
| | | | | | | will be released by transaction abort before _bt_end_vacuum gets called. If either of these "can't happen" errors actually happened, we'd freeze up trying to acquire an already-held lock. Latest word is that this does not explain Martin Pitt's trouble report, but it still looks like a bug.
* Fix pg_wchar_table's maxmblen field of EUC_CN, EUC_TW, MULE_INTERNALTatsuo Ishii2007-03-26
| | | | and GB18030. patches from ITAGAKI Takahiro.
* Fix 8.2 breakage of domains over array types, and add a regression test caseTom Lane2007-03-19
| | | | to cover it. Per report from Anton Pikhteryev.
* SPI_cursor_open failed to enforce that only read-only queries could beTom Lane2007-03-17
| | | | | | | executed in read_only mode. This could lead to various relatively-subtle failures, such as an allegedly stable function returning non-stable results. Bug goes all the way back to the introduction of read-only mode in 8.0. Per report from Gaetano Mendola.
* Fix a longstanding bug in VACUUM FULL's handling of update chains. The codeTom Lane2007-03-14
| | | | | | | | | | | | | | | | | | | | | | | 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.
* Fix a race condition that caused pg_database_size() and pg_tablespace_size()Alvaro Herrera2007-03-11
| | | | | | | | | to fail if an object was removed between calls to ReadDir() and stat(). Per discussion in pgsql-hackers. http://archives.postgresql.org/pgsql-hackers/2007-03/msg00671.php Bug report and patch by Michael Fuhr.
* Fix vac_update_relstats to ensure it always sends a relcache inval message,Tom Lane2007-03-08
| | | | | | | | even if none of the fields in the pg_class row change. This behavior is necessary to ensure other backends flush rd_targblock values that might point to truncated-away pages. We got this right pre-8.2 but it was broken by overoptimistic change to not write out the pg_class row if unchanged. Per report from Pavan Deolasee.
* Fix oversight in original coding of inline_function(): sinceTom Lane2007-03-06
| | | | | | | | | | | | | | check_sql_fn_retval allows binary-compatibility cases, the expression extracted from an inline-able SQL function might have a type that is only binary-compatible with the declared function result type. To avoid possibly changing the semantics of the expression, we should insert a RelabelType node in such cases. This has only been shown to have bad consequences in recent 8.1 and up releases, but I suspect there may be failure cases in the older branches too, so patch it all the way back. Per bug #3116 from Greg Mullane. Along the way, fix an omission in eval_const_expressions_mutator: it failed to copy the relabelformat field when processing a RelabelType. No known observable failures from this, but it definitely isn't intended behavior.
* Fix miscalculation of stats collector's write delay, introduced in revision ↵Tom Lane2007-03-01
| | | | 1.117.
* Fix markQueryForLocking() to work correctly in the presence of nested views.Tom Lane2007-03-01
| | | | | It has been wrong for this case since it was first written for 7.1 :-( Per report from Pavel Hanák.
* Fix portal management code to support non-default command completion tags forTom Lane2007-02-18
| | | | | | portals using PORTAL_UTIL_SELECT strategy. This is currently significant only for FETCH queries, which are supposed to include a count in the tag. Seems it's been broken since 7.4, but nobody noticed before Knut Lehre.
* Adjust the definition of is_pushed_down so that it's always true for INNERTom Lane2007-02-16
| | | | | | | | | JOIN quals, just like WHERE quals, even if they reference every one of the join's relations. Now that we can reorder outer and inner joins, it's possible for such a qual to end up being assigned to an outer join plan node, and we mustn't have it treated as a join qual rather than a filter qual for the node. (If it were, the join could produce null-extended rows that it shouldn't.) Per bug report from Pelle Johansson.
* Fix another problem in 8.2 changes that allowed "one-time" qual conditions toTom Lane2007-02-16
| | | | | | | be checked at plan levels below the top; namely, we have to allow for Result nodes inserted just above a nestloop inner indexscan. Should think about using the general Param mechanism to pass down outer-relation variables, but for the moment we need a back-patchable solution. Per report from Phil Frost.
* Restructure code that is responsible for ensuring that clauseless joins areTom Lane2007-02-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | considered when it is necessary to do so because of a join-order restriction (that is, an outer-join or IN-subselect construct). The former coding was a bit ad-hoc and inconsistent, and it missed some cases, as exposed by Mario Weilguni's recent bug report. His specific problem was that an IN could be turned into a "clauseless" join due to constant-propagation removing the IN's joinclause, and if the IN's subselect involved more than one relation and there was more than one such IN linking to the same upper relation, then the only valid join orders involve "bushy" plans but we would fail to consider the specific paths needed to get there. (See the example case added to the join regression test.) On examining the code I wonder if there weren't some other problem cases too; in particular it seems that GEQO was defending against a different set of corner cases than the main planner was. There was also an efficiency problem, in that when we did realize we needed a clauseless join because of an IN, we'd consider clauseless joins against every other relation whether this was sensible or not. It seems a better design is to use the outer-join and in-clause lists as a backup heuristic, just as the rule of joining only where there are joinclauses is a heuristic: we'll join two relations if they have a usable joinclause *or* this might be necessary to satisfy an outer-join or IN-clause join order restriction. I refactored the code to have just one place considering this instead of three, and made sure that it covered all the cases that any of them had been considering. Backpatch as far as 8.1 (which has only the IN-clause form of the disease). By rights 8.0 and 7.4 should have the bug too, but they accidentally fail to fail, because the joininfo structure used in those releases preserves some memory of there having once been a joinclause between the inner and outer sides of an IN, and so it leads the code in the right direction anyway. I'll be conservative and not touch them.
* Repair oversight in 8.2 change that improved the handling of "pseudoconstant"Tom Lane2007-02-15
| | | | | | | | | WHERE clauses. createplan.c is now willing to stick a gating Result node almost anywhere in the plan tree, and in particular one can wind up directly underneath a MergeJoin node. This means it had better be willing to handle Mark/Restore. Fortunately, that's trivial in such cases, since we can just pass off the call to the input node (which the planner has previously ensured can handle Mark/Restore). Per report from Phil Frost.
* Disallow committing a prepared transaction unless we are in the same databaseTom Lane2007-02-13
| | | | | it was executed in. Someday it might be nice to allow cross-DB commits, but work would be needed in NOTIFY and perhaps other places. Per Heikki.
* Repair bug in 8.2's new logic for planning outer joins: we have to allow joinsTom Lane2007-02-13
| | | | | | | | that overlap an outer join's min_righthand but aren't fully contained in it, to support joining within the RHS after having performed an outer join that can commute with this one. Aside from the direct fix in make_join_rel(), fix has_join_restriction() and GEQO's desirable_join() to consider this possibility. Per report from Ian Harding.
* Fix for early log messages during postmaster startup getting lost whenMagnus Hagander2007-02-11
| | | | | | | | running as a service on Win32. Per report from Harald Armin Massa. Backpatch to 8.2.
* Fix bug when localized to_char() day or month names were incorectlyBruce Momjian2007-02-08
| | | | | | | | trnasformed to lower or upper string. Backpatch to 8.2.X. Pavel Stehule
* This patch fixes shared_preload_libraries on Windows hosts. It forcesBruce Momjian2007-02-08
| | | | | | | | each backend to re-load all shared_preload_libraries. Backpatch to 8.2.X. Korry Douglas
* Fix an error in the original coding of holdable cursors: PersistHoldablePortalTom Lane2007-02-06
| | | | | | | | | | | 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.
* Remove typmod checking from the recent security-related patches. It turnsTom Lane2007-02-06
| | | | | | | | | | | | | out that ExecEvalVar and friends don't necessarily have access to a tuple descriptor with correct typmod: it definitely can contain -1, and possibly might contain other values that are different from the Var's value. Arguably this should be cleaned up someday, but it's not a simple change, and in any case typmod discrepancies don't pose a security hazard. Per reports from numerous people :-( I'm not entirely sure whether the failure can occur in 8.0 --- the simple test cases reported so far don't trigger it there. But back-patch the change all the way anyway.
* Fix a performance regression in 8.2: optimization of MIN/MAX into indexscansTom Lane2007-02-06
| | | | | | | had stopped working for tables buried inside views or sub-selects. This is because I had gotten rid of the simplify_jointree() preprocessing step, and optimize_minmax_aggregates() wasn't smart enough to deal with a non-canonical FromExpr. Per gripe from Bill Howe.
* Don't MAXALIGN in the checks to decide whether a tuple is over TOAST'sTom Lane2007-02-04
| | | | | | | | | | | | | | | | | | | | | | | | | | threshold for tuple length. On 4-byte-MAXALIGN machines, the toast code creates tuples that have t_len exactly TOAST_TUPLE_THRESHOLD ... but this number is not itself maxaligned, so if heap_insert maxaligns t_len before comparing to TOAST_TUPLE_THRESHOLD, it'll uselessly recurse back to tuptoaster.c, wasting cycles. (It turns out that this does not happen on 8-byte-MAXALIGN machines, because for them the outer MAXALIGN in the TOAST_MAX_CHUNK_SIZE macro reduces TOAST_MAX_CHUNK_SIZE so that toast tuples will be less than TOAST_TUPLE_THRESHOLD in size. That MAXALIGN is really incorrect, but we can't remove it now, see below.) There isn't any particular value in maxaligning before comparing to the thresholds, so just don't do that, which saves a small number of cycles in itself. These numbers should be rejiggered to minimize wasted space on toast-relation pages, but we can't do that in the back branches because changing TOAST_MAX_CHUNK_SIZE would force an initdb (by changing the contents of toast tables). We can move the toast decision thresholds a bit, though, which is what this patch effectively does. Thanks to Pavan Deolasee for discovering the unintended recursion. Back-patch into 8.2, but not further, pending more testing. (HEAD is about to get a further patch modifying the thresholds, so it won't help much for testing this form of the patch.)
* Repair failure to check that a table is still compatible with a previouslyTom Lane2007-02-02
| | | | | | | | | | | | | | | | | | | | | | 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
* Repair insufficiently careful type checking for SQL-language functions:Tom Lane2007-02-02
| | | | | | | | | | | | | | | | we should check that the function code returns the claimed result datatype every time we parse the function for execution. Formerly, for simple scalar result types we assumed the creation-time check was sufficient, but this fails if the function selects from a table that's been redefined since then, and even more obviously fails if check_function_bodies had been OFF. 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-2007-0555
* Translation updatesPeter Eisentraut2007-01-31
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* Clarify paramater handling for pg_get_serial_sequence().Bruce Momjian2007-01-30
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* Repair oversight in creation of "append relations": we should set upTom Lane2007-01-28
| | | | | rel->tuples as well as rel->rows, since some estimation functions expect both to be valid in every baserel. Per report from Dave Dutcher.
* Dept of second thoughts: the IQ of estimate_array_length() needs to beTom Lane2007-01-28
| | | | | kept on par with that of scalararraysel(), else estimates that should track might not. Hence teach it about binary-compatible cases, too.
* Fix scalararraysel() to cope with binary-compatible cases, such as text[]Tom Lane2007-01-28
| | | | | | versus varchar[]. This oversight probably explains Ryan Holmes' recent complaint --- he was getting a generic selectivity estimate instead of anything intelligent.
* Correct an old logic error in btree page splitting: when considering a splitTom Lane2007-01-27
| | | | | | | | | | | | exactly at the point where we need to insert a new item, the calculation used the wrong size for the "high key" of the new left page. This could lead to choosing an unworkable split, resulting in "PANIC: failed to add item to the left sibling" (or "right sibling") failure. Although this bug has been there a long time, it's very difficult to trigger a failure before 8.2, since there was generally a lot of free space on both sides of a chosen split. In 8.2, where the user-selected fill factor determines how much free space the code tries to leave, an unworkable split is much more likely. Report by Joe Conway, diagnosis and fix by Heikki Linnakangas.
* Back-port changes of Jan 16 and 17 to "revoke" pending fsync requests duringTom Lane2007-01-27
| | | | | | | | | 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.
* On Windows, use pgwin32_waitforsinglesocket() instead of select() to wait forTom Lane2007-01-26
| | | | | | | | | | input in the stats collector. Our select() emulation is apparently buggy for UDP sockets :-(. This should resolve problems with stats collection (and hence autovacuum) failing under more than minimal load. Diagnosis and patch by Magnus Hagander. Patch probably needs to be back-ported to 8.1 and 8.0, but first let's see if it makes the buildfarm happy...
* Properly detoast access to bytea field pg_trigger.tgargs. Old codeBruce Momjian2007-01-25
| | | | | | might cause server crash. Backpatch to 8.2.X.
* Get pg_utf_mblen(), pg_utf2wchar_with_len(), and utf2ucs() all on the sameTom Lane2007-01-24
| | | | | | | | | | | | | | | | | | | | | page about the maximum UTF8 sequence length we support (4 bytes since 8.1, 3 before that). pg_utf2wchar_with_len never got updated to support 4-byte characters at all, and in any case had a buffer-overrun risk in that it could produce multiple pg_wchars from what mblen claims to be just one UTF8 character. The only reason we don't have a major security hole is that most callers allocate worst-case output buffers; the sole exception in released versions appears to be pre-8.2 iwchareq() (ie, ILIKE), which can be crashed due to zeroing out its return address --- but AFAICS that can't be exploited for anything more than a crash, due to inability to control what gets written there. Per report from James Russell and Michael Fuhr. Pre-8.1 the risk is much less, but I still think pg_utf2wchar_with_len's behavior given an incomplete final character risks buffer overrun, so back-patch that logic change anyway. This patch also makes sure that UTF8 sequences exceeding the supported length (whichever it is) are consistently treated as error cases, rather than being treated like a valid shorter sequence in some places.
* Relax an Assert() that has been found to be too strict in some situationsTom Lane2007-01-24
| | | | | | | involving unions of types having typmods. Variants of the failure are known to occur in 8.1 and up; not sure if it's possible in 8.0 and 7.4, but since the code exists that far back, I'll just patch 'em all. Per report from Brian Hurt.
* Add documentation of memory and time units to postgresql.conf.Bruce Momjian2007-01-20
| | | | Backpatch to 8.2.X for new initdbs.
* Fix incorrect permissions check in information_schema.key_column_usage view:Tom Lane2007-01-16
| | | | | | | | | | it was checking a pg_constraint OID instead of pg_class OID, resulting in "relation with OID nnnnn does not exist" failures for anyone who wasn't owner of the table being examined. Per bug #2848 from Laurence Rowe. Note: for existing 8.2 installations a simple version update won't fix this; the easiest fix is to CREATE OR REPLACE this view with the corrected definition.
* Fix handling of CC (century) format spec in to_date/to_char. According toTom Lane2007-01-12
| | | | | | | | standard convention the 21st century runs from 2001-2100, not 2000-2099, so make it work like that. Per bug #2885 from Akio Iwaasa. Backpatch to 8.2, but no further, since this is really a definitional change; users of older branches are probably more interested in stability.
* Fix a performance problem in databases with large numbers of tablesTom Lane2007-01-11
| | | | | | | | | | | (or other types of pg_class entry): the function pgstat_vacuum_tabstat, invoked during VACUUM startup, had runtime proportional to the number of stats table entries times the number of pg_class rows; in other words O(N^2) if the stats collector's information is reasonably complete. Replace list searching with a hash table to bring it back to O(N) behavior. Per report from kim at myemma.com. Back-patch as far as 8.1; 8.0 and before use different coding here.
* Tweak joinlist creation to avoid generating useless one-element subproblemsTom Lane2007-01-08
| | | | | | | | | | when collapsing of JOIN trees is stopped by join_collapse_limit. For instance a list of 11 LEFT JOINs with limit 8 now produces something like ((1 2 3 4 5 6 7 8) 9 10 11 12) instead of (((1 2 3 4 5 6 7 8) (9)) 10 11 12) The latter structure is really only required for a FULL JOIN. Noted while studying an example from Shane Ambler.
* Remove cost_hashjoin's very ancient hack to discourage (once, entirely forbid)Tom Lane2007-01-08
| | | | | | | | | | | hash joins with the estimated-larger relation on the inside. There are several cases where doing that makes perfect sense, and in cases where it doesn't, the regular cost computation really ought to be able to figure that out. Make some marginal tweaks in said computation to try to get results approximating reality a bit better. Per an example from Shane Ambler. Also, fix an oversight in the original patch to add seq_page_cost: the costs of spilling a hash join to disk should be scaled by seq_page_cost.
* Fix oversight in handling of row-comparison index keys: if the row comparisonTom Lane2007-01-07
| | | | | | | | | | | doesn't exactly match the index, we may have to change our initial positioning strategy. For example, given an index on (f1,f2,f3) and a WHERE condition "ROW(f1,f3) > ROW(2,3)", the code extracted the initial-positioning condition "f1 > 2", which is wrong ... it has to be "f1 >= 2", else some rows matching the WHERE condition may fail to be returned. Applying patch to 8.2 only --- I'll fix it in HEAD later as part of the planned index improvements (reverse-sort and NULLS FIRST/LAST work).
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