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* Add context info to OAT_POST_CREATE security hookAlvaro Herrera2012-10-23
| | | | | | | | | ... and have sepgsql use it to determine whether to check permissions during certain operations. Indexes that are being created as a result of REINDEX, for instance, do not need to have their permissions checked; they were already checked when the index was created. Author: KaiGai Kohei, slightly revised by me
* Make CREATE AGGREGATE complain if the initcond is invalid for the datatype.Tom Lane2012-10-04
| | | | | | | | | | | | | The initial transition value is stored as a text string and not fed to the transition type's input function until runtime (so that values such as "now" don't get frozen at creation time). Previously, CREATE AGGREGATE didn't do anything with it but that, which meant that even erroneous values would be accepted and not complained of until the aggregate is used. This seems unhelpful, and it's confused at least one user, as in Rhys Stewart's recent report. It seems worth taking a few more cycles to invoke the input function and verify that the value is acceptable. We can't do this if the transition type is polymorphic, but in normal aggregates we know the actual transition type so we can call the right input function.
* Support CREATE SCHEMA IF NOT EXISTS.Tom Lane2012-10-03
| | | | | | | | Per discussion, schema-element subcommands are not allowed together with this option, since it's not very obvious what should happen to the element objects. Fabrízio de Royes Mello
* refactor ALTER some-obj SET OWNER implementationAlvaro Herrera2012-10-03
| | | | | | | | | | Remove duplicate implementation of catalog munging and miscellaneous privilege and consistency checks. Instead rely on already existing data in objectaddress.c to do the work. Author: KaiGai Kohei Tweaked by me Reviewed by Robert Haas
* Refactor "ALTER some-obj SET SCHEMA" implementationAlvaro Herrera2012-10-02
| | | | | | | | | | | Instead of having each object type implement the catalog munging independently, centralize knowledge about how to do it and expand the existing table in objectaddress.c with enough data about each object type to support this operation. Author: KaiGai Kohei Tweaks by me Reviewed by Robert Haas
* Allow IF NOT EXISTS when add a new enum label.Andrew Dunstan2012-09-22
| | | | | | | | If the label is already in the enum the statement becomes a no-op. This will reduce the pain that comes from our not allowing this operation inside a transaction block. Andrew Dunstan, reviewed by Tom Lane and Magnus Hagander.
* Improve ruleutils.c's heuristics for dealing with rangetable aliases.Tom Lane2012-09-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | The previous scheme had bugs in some corner cases involving tables that had been renamed since a view was made. This could result in dumped views that failed to reload or reloaded incorrectly, as seen in bug #7553 from Lloyd Albin, as well as in some pgsql-hackers discussion back in January. Also, its behavior for printing EXPLAIN plans was sometimes confusing because of willingness to use the same alias for multiple RTEs (it was Ashutosh Bapat's complaint about that aspect that started the January thread). To fix, ensure that each RTE in the query has a unique unqualified alias, by modifying the alias if necessary (we add "_" and digits as needed to create a non-conflicting name). Then we can just print its variables with that alias, avoiding the confusing and bug-prone scheme of sometimes schema-qualifying variable names. In EXPLAIN, it proves to be expedient to take the further step of only assigning such aliases to RTEs that are actually referenced in the query, since the planner has a habit of generating extra RTEs with the same alias in situations such as inheritance-tree expansion. Although this fixes a bug of very long standing, I'm hesitant to back-patch such a noticeable behavioral change. My experiments while creating a regression test convinced me that actually incorrect output (as opposed to confusing output) occurs only in very narrow cases, which is backed up by the lack of previous complaints from the field. So we may be better off living with it in released branches; and in any case it'd be smart to let this ripen awhile in HEAD before we consider back-patching it.
* Remove execdesc.h inclusion from tcopprot.hAlvaro Herrera2012-09-20
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* Fix a couple other leftover uses of 'conisonly' terminology.Tom Lane2012-09-12
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* Split tuple struct defs from htup.h to htup_details.hAlvaro Herrera2012-08-30
| | | | | | | | | | | | This reduces unnecessary exposure of other headers through htup.h, which is very widely included by many files. I have chosen to move the function prototypes to the new file as well, because that means htup.h no longer needs to include tupdesc.h. In itself this doesn't have much effect in indirect inclusion of tupdesc.h throughout the tree, because it's also required by execnodes.h; but it's something to explore in the future, and it seemed best to do the htup.h change now while I'm busy with it.
* Comment fixes.Robert Haas2012-08-30
| | | | Jeff Davis, somewhat edited by me
* Split heapam_xlog.h from heapam.hAlvaro Herrera2012-08-28
| | | | | | | | | | | | The heapam XLog functions are used by other modules, not all of which are interested in the rest of the heapam API. With this, we let them get just the XLog stuff in which they are interested and not pollute them with unrelated includes. Also, since heapam.h no longer requires xlog.h, many files that do include heapam.h no longer get xlog.h automatically, including a few headers. This is useful because heapam.h is getting pulled in by execnodes.h, which is in turn included by a lot of files.
* Split resowner.hAlvaro Herrera2012-08-28
| | | | | This lets files that are mere users of ResourceOwner not automatically include the headers for stuff that is managed by the resowner mechanism.
* Fix issues with checks for unsupported transaction states in Hot Standby.Tom Lane2012-08-24
| | | | | | | | | | | | | | | | | | | | | | | | | The GUC check hooks for transaction_read_only and transaction_isolation tried to check RecoveryInProgress(), so as to disallow setting read/write mode or serializable isolation level (respectively) in hot standby sessions. However, GUC check hooks can be called in many situations where we're not connected to shared memory at all, resulting in a crash in RecoveryInProgress(). Among other cases, this results in EXEC_BACKEND builds crashing during child process start if default_transaction_isolation is serializable, as reported by Heikki Linnakangas. Protect those calls by silently allowing any setting when not inside a transaction; which is okay anyway since these GUCs are always reset at start of transaction. Also, add a check to GetSerializableTransactionSnapshot() to complain if we are in hot standby. We need that check despite the one in check_XactIsoLevel() because default_transaction_isolation could be serializable. We don't want to complain any sooner than this in such cases, since that would prevent running transactions at all in such a state; but a transaction can be run, if SET TRANSACTION ISOLATION is done before setting a snapshot. Per report some months ago from Robert Haas. Back-patch to 9.1, since these problems were introduced by the SSI patch. Kevin Grittner and Tom Lane, with ideas from Heikki Linnakangas
* Disallow extensions from owning the schema they are assigned to.Tom Lane2012-08-15
| | | | | | | | | | | This situation creates a dependency loop that confuses pg_dump and probably other things. Moreover, since the mental model is that the extension "contains" schemas it owns, but "is contained in" its extschema (even though neither is strictly true), having both true at once is confusing for people too. So prevent the situation from being set up. Reported and patched by Thom Brown. Back-patch to 9.1 where extensions were added.
* Fix dependencies generated during ALTER TABLE ADD CONSTRAINT USING INDEX.Tom Lane2012-08-11
| | | | | | | | | | | | | | | | | | This command generated new pg_depend entries linking the index to the constraint and the constraint to the table, which match the entries made when a unique or primary key constraint is built de novo. However, it did not bother to get rid of the entries linking the index directly to the table. We had considered the issue when the ADD CONSTRAINT USING INDEX patch was written, and concluded that we didn't need to get rid of the extra entries. But this is wrong: ALTER COLUMN TYPE wasn't expecting such redundant dependencies to exist, as reported by Hubert Depesz Lubaczewski. On reflection it seems rather likely to break other things as well, since there are many bits of code that crawl pg_depend for one purpose or another, and most of them are pretty naive about what relationships they're expecting to find. Fortunately it's not that hard to get rid of the extra dependency entries, so let's do that. Back-patch to 9.1, where ALTER TABLE ADD CONSTRAINT USING INDEX was added.
* Centralize the logic for detecting misplaced aggregates, window funcs, etc.Tom Lane2012-08-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | Formerly we relied on checking after-the-fact to see if an expression contained aggregates, window functions, or sub-selects when it shouldn't. This is grotty, easily forgotten (indeed, we had forgotten to teach DefineIndex about rejecting window functions), and none too efficient since it requires extra traversals of the parse tree. To improve matters, define an enum type that classifies all SQL sub-expressions, store it in ParseState to show what kind of expression we are currently parsing, and make transformAggregateCall, transformWindowFuncCall, and transformSubLink check the expression type and throw error if the type indicates the construct is disallowed. This allows removal of a large number of ad-hoc checks scattered around the code base. The enum type is sufficiently fine-grained that we can still produce error messages of at least the same specificity as before. Bringing these error checks together revealed that we'd been none too consistent about phrasing of the error messages, so standardize the wording a bit. Also, rewrite checking of aggregate arguments so that it requires only one traversal of the arguments, rather than up to three as before. In passing, clean up some more comments left over from add_missing_from support, and annotate some tests that I think are dead code now that that's gone. (I didn't risk actually removing said dead code, though.)
* Fix typo in commentAlvaro Herrera2012-08-08
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* Fix longstanding crash-safety bug with newly-created-or-reset sequences.Tom Lane2012-07-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If a crash occurred immediately after the first nextval() call for a serial column, WAL replay would restore the sequence to a state in which it appeared that no nextval() had been done, thus allowing the first sequence value to be returned again by the next nextval() call; as reported in bug #6748 from Xiangming Mei. More generally, the problem would occur if an ALTER SEQUENCE was executed on a freshly created or reset sequence. (The manifestation with serial columns was introduced in 8.2 when we added an ALTER SEQUENCE OWNED BY step to serial column creation.) The cause is that sequence creation attempted to save one WAL entry by writing out a WAL record that made it appear that the first nextval() had already happened (viz, with is_called = true), while marking the sequence's in-database state with log_cnt = 1 to show that the first nextval() need not emit a WAL record. However, ALTER SEQUENCE would emit a new WAL entry reflecting the actual in-database state (with is_called = false). Then, nextval would allocate the first sequence value and set is_called = true, but it would trust the log_cnt value and not emit any WAL record. A crash at this point would thus restore the sequence to its post-ALTER state, causing the next nextval() call to return the first sequence value again. To fix, get rid of the idea of logging an is_called status different from reality. This means that the first nextval-driven WAL record will happen at the first nextval call not the second, but the marginal cost of that is pretty negligible. In addition, make sure that ALTER SEQUENCE resets log_cnt to zero in any case where it touches sequence parameters that affect future nextval results. This will result in some user-visible changes in the contents of a sequence's log_cnt column, as reflected in the patch's regression test changes; but no application should be depending on that anyway, since it was already true that log_cnt changes rather unpredictably depending on checkpoint timing. In addition, make some basically-cosmetic improvements to get rid of sequence.c's undesirable intimacy with page layout details. It was always really trying to WAL-log the contents of the sequence tuple, so we should have it do that directly using a HeapTuple's t_data and t_len, rather than backing into it with some magic assumptions about where the tuple would be on the sequence's page. Back-patch to all supported branches.
* Change syntax of new CHECK NO INHERIT constraintsAlvaro Herrera2012-07-24
| | | | | | | | | | The initially implemented syntax, "CHECK NO INHERIT (expr)" was not deemed very good, so switch to "CHECK (expr) NO INHERIT" instead. This way it looks similar to SQL-standards compliant constraint attribute. Backport to 9.2 where the new syntax and feature was introduced. Per discussion.
* connoinherit may be true only for CHECK constraintsAlvaro Herrera2012-07-20
| | | | | | | | | | | | | | | | | The code was setting it true for other constraints, which is bogus. Doing so caused bogus catalog entries for such constraints, and in particular caused an error to be raised when trying to drop a constraint of types other than CHECK from a table that has children, such as reported in bug #6712. In 9.2, additionally ignore connoinherit=true for other constraint types, to avoid having to force initdb; existing databases might already contain bogus catalog entries. Includes a catversion bump (in HEAD only). Bug report from Miroslav Šulc Analysis from Amit Kapila and Noah Misch; Amit also contributed the patch.
* Make new event trigger facility actually do something.Robert Haas2012-07-20
| | | | | | | | | | | | | | | | Commit 3855968f328918b6cd1401dd11d109d471a54d40 added syntax, pg_dump, psql support, and documentation, but the triggers didn't actually fire. With this commit, they now do. This is still a pretty basic facility overall because event triggers do not get a whole lot of information about what the user is trying to do unless you write them in C; and there's still no option to fire them anywhere except at the very beginning of the execution sequence, but it's better than nothing, and a good building block for future work. Along the way, add a regression test for ALTER LARGE OBJECT, since testing of event triggers reveals that we haven't got one. Dimitri Fontaine and Robert Haas
* Syntax support and documentation for event triggers.Robert Haas2012-07-18
| | | | | | | | | | | | | | They don't actually do anything yet; that will get fixed in a follow-on commit. But this gets the basic infrastructure in place, including CREATE/ALTER/DROP EVENT TRIGGER; support for COMMENT, SECURITY LABEL, and ALTER EXTENSION .. ADD/DROP EVENT TRIGGER; pg_dump and psql support; and documentation for the anticipated initial feature set. Dimitri Fontaine, with review and a bunch of additional hacking by me. Thom Brown extensively reviewed earlier versions of this patch set, but there's not a whole lot of that code left in this commit, as it turns out.
* Avoid pre-determining index names during CREATE TABLE LIKE parsing.Tom Lane2012-07-16
| | | | | | | | | | | | | | | | | | | | | | | Formerly, when trying to copy both indexes and comments, CREATE TABLE LIKE had to pre-assign names to indexes that had comments, because it made up an explicit CommentStmt command to apply the comment and so it had to know the name for the index. This creates bad interactions with other indexes, as shown in bug #6734 from Daniele Varrazzo: the preassignment logic couldn't take any other indexes into account so it could choose a conflicting name. To fix, add a field to IndexStmt that allows it to carry a comment to be assigned to the new index. (This isn't a user-exposed feature of CREATE INDEX, only an internal option.) Now we don't need preassignment of index names in any situation. I also took the opportunity to refactor DefineIndex to accept the IndexStmt as such, rather than passing all its fields individually in a mile-long parameter list. Back-patch to 9.2, but no further, because it seems too dangerous to change IndexStmt or DefineIndex's API in released branches. The bug exists back to 9.0 where CREATE TABLE LIKE grew the ability to copy comments, but given the lack of prior complaints we'll just let it go unfixed before 9.2.
* Skip text->binary conversion of unnecessary columns in contrib/file_fdw.Tom Lane2012-07-12
| | | | | | | | | | | | When reading from a text- or CSV-format file in file_fdw, the datatype input routines can consume a significant fraction of the runtime. Often, the query does not need all the columns, so we can get a useful speed boost by skipping I/O conversion for unnecessary columns. To support this, add a "convert_selectively" option to the core COPY code. This is undocumented and not accessible from SQL (for now, anyway). Etsuro Fujita, reviewed by KaiGai Kohei
* Reduce messages about implicit indexes and sequences to DEBUG1.Robert Haas2012-07-04
| | | | | Per recent discussion on pgsql-hackers, these messages are too chatty for most users.
* Have REASSIGN OWNED work on extensions, tooAlvaro Herrera2012-07-03
| | | | | | | | | | | | | | | | | Per bug #6593, REASSIGN OWNED fails when the affected role has created an extension. Even though the user related to the extension is not nominally the owner, its OID appears on pg_shdepend and thus causes problems when the user is to be dropped. This commit adds code to change the "ownership" of the extension itself, not of the contained objects. This is fine because it's currently only called from REASSIGN OWNED, which would also modify the ownership of the contained objects. However, this is not sufficient for a working ALTER OWNER implementation extension. Back-patch to 9.1, where extensions were introduced. Bug #6593 reported by Emiliano Leporati.
* Prevent CREATE TABLE LIKE/INHERITS from (mis) copying whole-row Vars.Tom Lane2012-06-30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | If a CHECK constraint or index definition contained a whole-row Var (that is, "table.*"), an attempt to copy that definition via CREATE TABLE LIKE or table inheritance produced incorrect results: the copied Var still claimed to have the rowtype of the source table, rather than the created table. For the LIKE case, it seems reasonable to just throw error for this situation, since the point of LIKE is that the new table is not permanently coupled to the old, so there's no reason to assume its rowtype will stay compatible. In the inheritance case, we should ideally allow such constraints, but doing so will require nontrivial refactoring of CREATE TABLE processing (because we'd need to know the OID of the new table's rowtype before we adjust inherited CHECK constraints). In view of the lack of previous complaints, that doesn't seem worth the risk in a back-patched bug fix, so just make it throw error for the inheritance case as well. Along the way, replace change_varattnos_of_a_node() with a more robust function map_variable_attnos(), which is capable of being extended to handle insertion of ConvertRowtypeExpr whenever we get around to fixing the inheritance case nicely, and in the meantime it returns a failure indication to the caller so that a helpful message with some context can be thrown. Also, this code will do the right thing with subselects (if we ever allow them in CHECK or indexes), and it range-checks varattnos before using them to index into the map array. Per report from Sergey Konoplev. Back-patch to all supported branches.
* Fix NOTIFY to cope with I/O problems, such as out-of-disk-space.Tom Lane2012-06-29
| | | | | | | | | | | | | The LISTEN/NOTIFY subsystem got confused if SimpleLruZeroPage failed, which would typically happen as a result of a write() failure while attempting to dump a dirty pg_notify page out of memory. Subsequently, all attempts to send more NOTIFY messages would fail with messages like "Could not read from file "pg_notify/nnnn" at offset nnnnn: Success". Only restarting the server would clear this condition. Per reports from Kevin Grittner and Christoph Berg. Back-patch to 9.0, where the problem was introduced during the LISTEN/NOTIFY rewrite.
* Replace int2/int4 in C code with int16/int32Peter Eisentraut2012-06-25
| | | | | | | | | | The latter was already the dominant use, and it's preferable because in C the convention is that intXX means XX bits. Therefore, allowing mixed use of int2, int4, int8, int16, int32 is obviously confusing. Remove the typedefs for int2 and int4 for now. They don't seem to be widely used outside of the PostgreSQL source tree, and the few uses can probably be cleaned up by the time this ships.
* Repair comment mangled by a pgindent run long agoAlvaro Herrera2012-06-21
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* Improve tests for whether we can skip queueing RI enforcement triggers.Tom Lane2012-06-19
| | | | | | | | | | | | | During an update of a PK row, we can skip firing the RI trigger if any old key value is NULL, because then the row could not have had any matching rows in the FK table. Conversely, during an update of an FK row, the outcome is determined if any new key value is NULL. In either case it becomes unnecessary to compare individual key values. This patch was inspired by discussion of Vik Reykja's patch to use IS NOT DISTINCT semantics for the key comparisons. In the event there is no need for that and so this patch looks nothing like his, but he should still get credit for having re-opened consideration of the trigger skip logic.
* Refer to the default foreign key match style as MATCH SIMPLE internally.Tom Lane2012-06-17
| | | | | | | | | | | | Previously we followed the SQL92 wording, "MATCH <unspecified>", but since SQL99 there's been a less awkward way to refer to the default style. In addition to the code changes, pg_constraint.confmatchtype now stores this match style as 's' (SIMPLE) rather than 'u' (UNSPECIFIED). This doesn't affect pg_dump or psql because they use pg_get_constraintdef() to reconstruct foreign key definitions. But other client-side code might examine that column directly, so this change will have to be marked as an incompatibility in the 9.3 release notes.
* Improve reporting of permission errors for array typesPeter Eisentraut2012-06-15
| | | | | | | | | | | | | Because permissions are assigned to element types, not array types, complaining about permission denied on an array type would be misleading to users. So adjust the reporting to refer to the element type instead. In order not to duplicate the required logic in two dozen places, refactor the permission denied reporting for types a bit. pointed out by Yeb Havinga during the review of the type privilege feature
* Add more message pluralizationPeter Eisentraut2012-06-15
| | | | | Even though we can't do much about the case with multiple plurals in one sentence, we can fix the other cases.
* Remove RELKIND_UNCATALOGED.Robert Haas2012-06-14
| | | | | | | This may have been important at some point in the past, but it no longer does anything useful. Review by Tom Lane.
* Run pgindent on 9.2 source tree in preparation for first 9.3Bruce Momjian2012-06-10
| | | | commit-fest.
* Fix more crash-safe visibility map bugs, and improve comments.Robert Haas2012-06-07
| | | | | | | | | | | | | | | | | | | | | | | | | In lazy_scan_heap, we could issue bogus warnings about incorrect information in the visibility map, because we checked the visibility map bit before locking the heap page, creating a race condition. Fix by rechecking the visibility map bit before we complain. Rejigger some related logic so that we rely on the possibly-outdated all_visible_according_to_vm value as little as possible. In heap_multi_insert, it's not safe to clear the visibility map bit before beginning the critical section. The visibility map is not crash-safe unless we treat clearing the bit as a critical operation. Specifically, if the transaction were to error out after we set the bit and before entering the critical section, we could end up writing the heap page to disk (with the bit cleared) and crashing before the visibility map page made it to disk. That would be bad. heap_insert has this correct, but somehow the order of operations got rearranged when heap_multi_insert was added. Also, add some more comments to visibilitymap_test, lazy_scan_heap, and IndexOnlyNext, expounding on concurrency issues. Per extensive code review by Andres Freund, and further review by Tom Lane, who also made the original report about the bogus warnings.
* Force PL and range-type support functions to be owned by a superuser.Tom Lane2012-05-30
| | | | | | | | | | | | | | | We allow non-superusers to create procedural languages (with restrictions) and range datatypes. Previously, the automatically-created support functions for these objects ended up owned by the creating user. This represents a rather considerable security hazard, because the owning user might be able to alter a support function's definition in such a way as to crash the server, inject trojan-horse SQL code, or even execute arbitrary C code directly. It appears that right now the only actually exploitable problem is the infinite-recursion bug fixed in the previous patch for CVE-2012-2655. However, it's not hard to imagine that future additions of more ALTER FUNCTION capability might unintentionally open up new hazards. To forestall future problems, cause these support functions to be owned by the bootstrap superuser, not the user creating the parent object.
* Improve error message for ALTER COLUMN TYPE coercion failure.Tom Lane2012-05-16
| | | | | | | Per recent discussion, the error message for this was actually a trifle inaccurate, since it said "cannot be cast" which might be incorrect. Adjust that wording, and add a HINT suggesting that a USING clause might be needed.
* Update comments that became out-of-date with the PGXACT struct.Heikki Linnakangas2012-05-14
| | | | | | | | | | | When the "hot" members of PGPROC were split off to separate PGXACT structs, many PGPROC fields referred to in comments were moved to PGXACT, but the comments were neglected in the commit. Mostly this is just a search/replace of PGPROC with PGXACT, but the way the dummy PGPROC entries are created for prepared transactions changed more, making some of the comments totally bogus. Noah Misch
* Fix DROP TABLESPACE to unlink symlink when directory is not there.Tom Lane2012-05-13
| | | | | | | | | | | | | | | | | | | | | If the tablespace directory is missing entirely, we allow DROP TABLESPACE to go through, on the grounds that it should be possible to clean up the catalog entry in such a situation. However, we forgot that the pg_tblspc symlink might still be there. We should try to remove the symlink too (but not fail if it's no longer there), since not doing so can lead to weird behavior subsequently, as per report from Michael Nolan. There was some discussion of adding dependency links to prevent DROP TABLESPACE when the catalogs still contain references to the tablespace. That might be worth doing too, but it's an orthogonal question, and in any case wouldn't be back-patchable. Back-patch to 9.0, which is as far back as the logic looks like this. We could possibly do something similar in 8.x, but given the lack of reports I'm not sure it's worth the trouble, and anyway the case could not arise in the form the logic is meant to cover (namely, a post-DROP transaction rollback having resurrected the pg_tablespace entry after some or all of the filesystem infrastructure is gone).
* Prevent loss of init fork when truncating an unlogged table.Robert Haas2012-05-11
| | | | Fixes bug #6635, reported by Akira Kurosawa.
* Make "unexpected EOF" messages DEBUG1 unless in an open transactionMagnus Hagander2012-05-07
| | | | | | | "Unexpected EOF on client connection" without an open transaction is mostly noise, so turn it into DEBUG1. With an open transaction it's still indicating a problem, so keep those as ERROR, and change the message to indicate that it happened in a transaction.
* Rename I/O timing statistics columns to blk_read_time and blk_write_time.Tom Lane2012-04-29
| | | | | This seems more consistent with the pre-existing choices for names of other statistics columns. Rename assorted internal identifiers to match.
* Prevent index-only scans from returning wrong answers under Hot Standby.Robert Haas2012-04-26
| | | | | | | | | The alternative of disallowing index-only scans in HS operation was discussed, but the consensus was that it was better to treat marking a page all-visible as a recovery conflict for snapshots that could still fail to see XIDs on that page. We may in the future try to soften this, so that we simply force index scans to do heap fetches in cases where this may be an issue, rather than throwing a hard conflict.
* Casts to or from a domain type are ignored; warn and document.Robert Haas2012-04-24
| | | | | | | | Prohibiting this outright would break dumps taken from older versions that contain such casts, which would create far more pain than is justified here. Per report by Jaime Casanova and subsequent discussion.
* Lots of doc corrections.Robert Haas2012-04-23
| | | | Josh Kupershmidt
* Rearrange lazy_scan_heap to avoid visibility map race conditions.Robert Haas2012-04-23
| | | | | | | | | | | | | | | | | | | We must set the visibility map bit before releasing our exclusive lock on the heap page; otherwise, someone might clear the heap page bit before we set the visibility map bit, leading to a situation where the visibility map thinks the page is all-visible but it's really not. This problem has existed since 8.4, but it wasn't critical before we had index-only scans, since the worst case scenario was that the page wouldn't get vacuumed until the next scan_all vacuum. Along the way, a couple of minor, related improvements: (1) if we pause the heap scan to do an index vac cycle, release any visibility map page we're holding, since really long-running pins are not good for a variety of reasons; and (2) warn if we see a page that's marked all-visible in the visibility map but not on the page level, since that should never happen any more (it was allowed in previous releases, but not in 9.2).
* Recast "ONLY" column CHECK constraints as NO INHERITAlvaro Herrera2012-04-20
| | | | | | | | | | | | | | | | | The original syntax wasn't universally loved, and it didn't allow its usage in CREATE TABLE, only ALTER TABLE. It now works everywhere, and it also allows using ALTER TABLE ONLY to add an uninherited CHECK constraint, per discussion. The pg_constraint column has accordingly been renamed connoinherit. This commit partly reverts some of the changes in 61d81bd28dbec65a6b144e0cd3d0bfe25913c3ac, particularly some pg_dump and psql bits, because now pg_get_constraintdef includes the necessary NO INHERIT within the constraint definition. Author: Nikhil Sontakke Some tweaks by me