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* Improve representation of PlanRowMark.Tom Lane2015-03-15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch fixes two inadequacies of the PlanRowMark representation. First, that the original LockingClauseStrength isn't stored (and cannot be inferred for foreign tables, which always get ROW_MARK_COPY). Since some PlanRowMarks are created out of whole cloth and don't actually have an ancestral RowMarkClause, this requires adding a dummy LCS_NONE value to enum LockingClauseStrength, which is fairly annoying but the alternatives seem worse. This fix allows getting rid of the use of get_parse_rowmark() in FDWs (as per the discussion around commits 462bd95705a0c23b and 8ec8760fc87ecde0), and it simplifies some things elsewhere. Second, that the representation assumed that all child tables in an inheritance hierarchy would use the same RowMarkType. That's true today but will soon not be true. We add an "allMarkTypes" field that identifies the union of mark types used in all a parent table's children, and use that where appropriate (currently, only in preprocess_targetlist()). In passing fix a couple of minor infelicities left over from the SKIP LOCKED patch, notably that _outPlanRowMark still thought waitPolicy is a bool. Catversion bump is required because the numeric values of enum LockingClauseStrength can appear in on-disk rules. Extracted from a much larger patch to support foreign table inheritance; it seemed worth breaking this out, since it's a separable concern. Shigeru Hanada and Etsuro Fujita, somewhat modified by me
* Fix dumping of views that are just VALUES(...) but have column aliases.Tom Lane2015-02-25
| | | | | | | | | | | | | | | The "simple" path for printing VALUES clauses doesn't work if we need to attach nondefault column aliases, because there's noplace to do that in the minimal VALUES() syntax. So modify get_simple_values_rte() to detect nondefault aliases and treat that as a non-simple case. This further exposes that the "non-simple" path never actually worked; it didn't produce valid syntax. Fix that too. Per bug #12789 from Curtis McEnroe, and analysis by Andrew Gierth. Back-patch to all supported branches. Before 9.3, this also requires back-patching the part of commit 092d7ded29f36b0539046b23b81b9f0bf2d637f1 that created get_simple_values_rte() to begin with; inserting the extra test into the old factorization of that logic would've been too messy.
* Improve performance of EXPLAIN with large range tables.Tom Lane2015-01-15
| | | | | | | | | | | | | | | | | | | | | | | | | As of 9.3, ruleutils.c goes to some lengths to ensure that table and column aliases used in its output are unique. Of course this takes more time than was required before, which in itself isn't fatal. However, EXPLAIN was set up so that recalculation of the unique aliases was repeated for each subexpression printed in a plan. That results in O(N^2) time and memory consumption for large plan trees, which did not happen in older branches. Fortunately, the expensive work is the same across a whole plan tree, so there is no need to repeat it; we can do most of the initialization just once per query and re-use it for each subexpression. This buys back most (not all) of the performance loss since 9.2. We need an extra ExplainState field to hold the precalculated deparse context. That's no problem in HEAD, but in the back branches, expanding sizeof(ExplainState) seems risky because third-party extensions might have local variables of that struct type. So, in 9.4 and 9.3, introduce an auxiliary struct to keep sizeof(ExplainState) the same. We should refactor the APIs to avoid such local variables in future, but that's material for a separate HEAD-only commit. Per gripe from Alexey Bashtanov. Back-patch to 9.3 where the issue was introduced.
* Update copyright for 2015Bruce Momjian2015-01-06
| | | | Backpatch certain files through 9.0
* Rearrange CustomScan API.Tom Lane2014-11-21
| | | | | | | | | | | | | Make it work more like FDW plans do: instead of assuming that there are expressions in a CustomScan plan node that the core code doesn't know about, insist that all subexpressions that need planner attention be in a "custom_exprs" list in the Plan representation. (Of course, the custom plugin can break the list apart again at executor initialization.) This lets us revert the parts of the patch that exposed setrefs.c and subselect.c processing to the outside world. Also revert the GetSpecialCustomVar stuff in ruleutils.c; that concept may work in future, but it's far from fully baked right now.
* Introduce custom path and scan providers.Robert Haas2014-11-07
| | | | | | | | | | | This allows extension modules to define their own methods for scanning a relation, and get the core code to use them. It's unclear as yet how much use this capability will find, but we won't find out if we never commit it. KaiGai Kohei, reviewed at various times and in various levels of detail by Shigeru Hanada, Tom Lane, Andres Freund, Álvaro Herrera, and myself.
* Split builtins.h to a new header ruleutils.hAlvaro Herrera2014-10-08
| | | | | | | The new header contains many prototypes for functions in ruleutils.c that are not exposed to the SQL level. Reviewed by Andres Freund and Michael Paquier.
* Implement SKIP LOCKED for row-level locksAlvaro Herrera2014-10-07
| | | | | | | | | | | | | | | | | | This clause changes the behavior of SELECT locking clauses in the presence of locked rows: instead of causing a process to block waiting for the locks held by other processes (or raise an error, with NOWAIT), SKIP LOCKED makes the new reader skip over such rows. While this is not appropriate behavior for general purposes, there are some cases in which it is useful, such as queue-like tables. Catalog version bumped because this patch changes the representation of stored rules. Reviewed by Craig Ringer (based on a previous attempt at an implementation by Simon Riggs, who also provided input on the syntax used in the current patch), David Rowley, and Álvaro Herrera. Author: Thomas Munro
* Partial fix for dropped columns in functions returning composite.Tom Lane2014-07-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When a view has a function-returning-composite in FROM, and there are some dropped columns in the underlying composite type, ruleutils.c printed junk in the column alias list for the reconstructed FROM entry. Before 9.3, this was prevented by doing get_rte_attribute_is_dropped tests while printing the column alias list; but that solution is not currently available to us for reasons I'll explain below. Instead, check for empty-string entries in the alias list, which can only exist if that column position had been dropped at the time the view was made. (The parser fills in empty strings to preserve the invariant that the aliases correspond to physical column positions.) While this is sufficient to handle the case of columns dropped before the view was made, we have still got issues with columns dropped after the view was made. In particular, the view could contain Vars that explicitly reference such columns! The dependency machinery really ought to refuse the column drop attempt in such cases, as it would do when trying to drop a table column that's explicitly referenced in views. However, we currently neglect to store dependencies on columns of composite types, and fixing that is likely to be too big to be back-patchable (not to mention that existing views in existing databases would not have the needed pg_depend entries anyway). So I'll leave that for a separate patch. Pre-9.3, ruleutils would print such Vars normally (with their original column names) even though it suppressed their entries in the RTE's column alias list. This is certainly bogus, since the printed view definition would fail to reload, but at least it didn't crash. However, as of 9.3 the printed column alias list is tightly tied to the names printed for Vars; so we can't treat columns as dropped for one purpose and not dropped for the other. This is why we can't just put back the get_rte_attribute_is_dropped test: it results in an assertion failure if the view in fact contains any Vars referencing the dropped column. Once we've got dependencies preventing such cases, we'll probably want to do it that way instead of relying on the empty-string test used here. This fix turned up a very ancient bug in outfuncs/readfuncs, namely that T_String nodes containing empty strings were not dumped/reloaded correctly: the node was printed as "<>" which is read as a string value of <>. Since (per SQL) we disallow empty-string identifiers, such nodes don't occur normally, which is why we'd not noticed. (Such nodes aren't used for literal constants, just identifiers.) Per report from Marc Schablewski. Back-patch to 9.3 which is where the rule printing behavior changed. The dangling-variable case is broken all the way back, but that's not what his complaint is about.
* Implement UPDATE tab SET (col1,col2,...) = (SELECT ...), ...Tom Lane2014-06-18
| | | | | | | | | | | | | | | | This SQL-standard feature allows a sub-SELECT yielding multiple columns (but only one row) to be used to compute the new values of several columns to be updated. While the same results can be had with an independent sub-SELECT per column, such a workaround can require a great deal of duplicated computation. The standard actually says that the source for a multi-column assignment could be any row-valued expression. The implementation used here is tightly tied to our existing sub-SELECT support and can't handle other cases; the Bison grammar would have some issues with them too. However, I don't feel too bad about this since other cases can be converted into sub-SELECTs. For instance, "SET (a,b,c) = row_valued_function(x)" could be written "SET (a,b,c) = (SELECT * FROM row_valued_function(x))".
* pgindent run for 9.4Bruce Momjian2014-05-06
| | | | | This includes removing tabs after periods in C comments, which was applied to back branches, so this change should not effect backpatching.
* Fix yet another corner case in dumping rules/views with USING clauses.Tom Lane2014-05-01
| | | | | | | | | | | | | | | | ruleutils.c tries to cope with additions/deletions/renamings of columns in tables referenced by views, by means of adding machine-generated aliases to the printed form of a view when needed to preserve the original semantics. A recent blog post by Marko Tiikkaja pointed out a case I'd missed though: if one input of a join with USING is itself a join, there is nothing to stop the user from adding a column of the same name as the USING column to whichever side of the sub-join didn't provide the USING column. And then there'll be an error when the view is re-parsed, since now the sub-join exposes two columns matching the USING specification. We were catching a lot of related cases, but not this one, so add some logic to cope with it. Back-patch to 9.3, which is the first release that makes any serious attempt to cope with such cases (cf commit 2ffa740be and follow-ons).
* Check for interrupts and stack overflow during rule/view dumps.Tom Lane2014-04-30
| | | | | | | | | Since ruleutils.c recurses, it could be driven to stack overflow by deeply nested constructs. Very large queries might also take long enough to deparse that a check for interrupts seems like a good idea. Stick appropriate tests into a couple of key places. Noted by Greg Stark. Back-patch to all supported branches.
* Reduce indentation/parenthesization of set operations in rule/view dumps.Tom Lane2014-04-30
| | | | | | | | | | | | | | | | | | | | | | | | | A query such as "SELECT x UNION SELECT y UNION SELECT z UNION ..." produces a left-deep nested parse tree, which we formerly showed in its full nested glory and with all the possible parentheses. This does little for readability, though, and long UNION lists resulting in excessive indentation are common. Instead, let's omit parentheses and indent all the subqueries at the same level in such cases. This patch skips indentation/parenthesization whenever the lefthand input of a SetOperationStmt is another SetOperationStmt of the same kind and ALL/DISTINCT property. We could teach the code the exact syntactic precedence of set operations and thereby avoid parenthesization in some more cases, but it's not clear that that'd be a readability win: it seems better to parenthesize if the set operation changes. (As an example, if there's one UNION in a long list of UNION ALL, it now stands out like a sore thumb, which seems like a good thing.) Back-patch to 9.3. This completes our response to a complaint from Greg Stark that since commit 62e666400d there's a performance problem in pg_dump for views containing long UNION sequences (or other types of deeply nested constructs). The previous commit 0601cb54dac14d979d726ab2ebeda251ae36e857 handles the general problem, but this one makes the specific case of UNION lists look a lot nicer.
* Limit overall indentation in rule/view dumps.Tom Lane2014-04-30
| | | | | | | | | | | | | | | | | Continuing to indent no matter how deeply nested we get doesn't really do anything for readability; what's worse, it results in O(N^2) total whitespace, which can become a performance and memory-consumption issue. To address this, once we get past 40 characters of indentation, reduce the indentation step distance 4x, and also limit the maximum indentation by reducing it modulo 40. This latter choice is a bit weird at first glance, but it seems to preserve readability better than a simple cap would do. Back-patch to 9.3, because since commit 62e666400d the performance issue is a hazard for pg_dump. Greg Stark and Tom Lane
* Fix indentation of JOIN clauses in rule/view dumps.Tom Lane2014-04-30
| | | | | | | | | | | | | | | | | | | | The code attempted to outdent JOIN clauses further left than the parent FROM keyword, which was odd in any case, and led to inconsistent formatting since in simple cases the clauses couldn't be moved any further left than that. And it left a permanent decrement of the indentation level, causing subsequent lines to be much further left than they should be (again, this couldn't be seen in simple cases for lack of indentation to give up). After a little experimentation I chose to make it indent JOIN keywords two spaces from the parent FROM, which is one space more than the join's lefthand input in cases where that appears on a different line from FROM. Back-patch to 9.3. This is a purely cosmetic change, and the bug is quite old, so that may seem arbitrary; but we are going to be making some other changes to the indentation behavior in both HEAD and 9.3, so it seems reasonable to include this in 9.3 too. I committed this one first because its effects are more visible in the regression test results as they currently stand than they will be later.
* Reduce lock levels of some ALTER TABLE cmdsSimon Riggs2014-04-06
| | | | | | | | | | | | | | | | | VALIDATE CONSTRAINT CLUSTER ON SET WITHOUT CLUSTER ALTER COLUMN SET STATISTICS ALTER COLUMN SET () ALTER COLUMN RESET () All other sub-commands use AccessExclusiveLock Simon Riggs and Noah Misch Reviews by Robert Haas and Andres Freund
* Fix non-equivalence of VARIADIC and non-VARIADIC function call formats.Tom Lane2014-04-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For variadic functions (other than VARIADIC ANY), the syntaxes foo(x,y,...) and foo(VARIADIC ARRAY[x,y,...]) should be considered equivalent, since the former is converted to the latter at parse time. They have indeed been equivalent, in all releases before 9.3. However, commit 75b39e790 made an ill-considered decision to record which syntax had been used in FuncExpr nodes, and then to make equal() test that in checking node equality --- which caused the syntaxes to not be seen as equivalent by the planner. This is the underlying cause of bug #9817 from Dmitry Ryabov. It might seem that a quick fix would be to make equal() disregard FuncExpr.funcvariadic, but the same commit made that untenable, because the field actually *is* semantically significant for some VARIADIC ANY functions. This patch instead adopts the approach of redefining funcvariadic (and aggvariadic, in HEAD) as meaning that the last argument is a variadic array, whether it got that way by parser intervention or was supplied explicitly by the user. Therefore the value will always be true for non-ANY variadic functions, restoring the principle of equivalence. (However, the planner will continue to consider use of VARIADIC as a meaningful difference for VARIADIC ANY functions, even though some such functions might disregard it.) In HEAD, this change lets us simplify the decompilation logic in ruleutils.c, since the funcvariadic/aggvariadic flag tells directly whether to print VARIADIC. However, in 9.3 we have to continue to cope with existing stored rules/views that might contain the previous definition. Fortunately, this just means no change in ruleutils.c, since its existing behavior effectively ignores funcvariadic for all cases other than VARIADIC ANY functions. In HEAD, bump catversion to reflect the fact that FuncExpr.funcvariadic changed meanings; this is sort of pro forma, since I don't believe any built-in views are affected. Unfortunately, this patch doesn't magically fix everything for affected 9.3 users. After installing 9.3.5, they might need to recreate their rules/views/indexes containing variadic function calls in order to get everything consistent with the new definition. As in the cited bug, the symptom of a problem would be failure to use a nominally matching index that has a variadic function call in its definition. We'll need to mention this in the 9.3.5 release notes.
* Avoid getting more than AccessShareLock when deparsing a query.Tom Lane2014-03-06
| | | | | | | | | | | | | | | | | | | | In make_ruledef and get_query_def, we have long used AcquireRewriteLocks to ensure that the querytree we are about to deparse is up-to-date and the schemas of the underlying relations aren't changing. Howwever, that function thinks the query is about to be executed, so it acquires locks that are stronger than necessary for the purpose of deparsing. Thus for example, if pg_dump asks to deparse a rule that includes "INSERT INTO t", we'd acquire RowExclusiveLock on t. That results in interference with concurrent transactions that might for example ask for ShareLock on t. Since pg_dump is documented as being purely read-only, this is unexpected. (Worse, it used to actually be read-only; this behavior dates back only to 8.1, cf commit ba4200246.) Fix this by adding a parameter to AcquireRewriteLocks to tell it whether we want the "real" execution locks or only AccessShareLock. Report, diagnosis, and patch by Dean Rasheed. Back-patch to all supported branches.
* Update copyright for 2014Bruce Momjian2014-01-07
| | | | | Update all files in head, and files COPYRIGHT and legal.sgml in all back branches.
* Support ordered-set (WITHIN GROUP) aggregates.Tom Lane2013-12-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch introduces generic support for ordered-set and hypothetical-set aggregate functions, as well as implementations of the instances defined in SQL:2008 (percentile_cont(), percentile_disc(), rank(), dense_rank(), percent_rank(), cume_dist()). We also added mode() though it is not in the spec, as well as versions of percentile_cont() and percentile_disc() that can compute multiple percentile values in one pass over the data. Unlike the original submission, this patch puts full control of the sorting process in the hands of the aggregate's support functions. To allow the support functions to find out how they're supposed to sort, a new API function AggGetAggref() is added to nodeAgg.c. This allows retrieval of the aggregate call's Aggref node, which may have other uses beyond the immediate need. There is also support for ordered-set aggregates to install cleanup callback functions, so that they can be sure that infrastructure such as tuplesort objects gets cleaned up. In passing, make some fixes in the recently-added support for variadic aggregates, and make some editorial adjustments in the recent FILTER additions for aggregates. Also, simplify use of IsBinaryCoercible() by allowing it to succeed whenever the target type is ANY or ANYELEMENT. It was inconsistent that it dealt with other polymorphic target types but not these. Atri Sharma and Andrew Gierth; reviewed by Pavel Stehule and Vik Fearing, and rather heavily editorialized upon by Tom Lane
* Rename TABLE() to ROWS FROM().Noah Misch2013-12-10
| | | | | | | SQL-standard TABLE() is a subset of UNNEST(); they deal with arrays and other collection types. This feature, however, deals with set-returning functions. Use a different syntax for this feature to keep open the possibility of implementing the standard TABLE().
* Implement information_schema.parameters.parameter_default columnPeter Eisentraut2013-11-26
| | | | | | Reviewed-by: Ali Dar <ali.munir.dar@gmail.com> Reviewed-by: Amit Khandekar <amit.khandekar@enterprisedb.com> Reviewed-by: Rodolfo Campero <rodolfo.campero@anachronics.com>
* Fix thinko in SPI_execute_plan() callsPeter Eisentraut2013-11-23
| | | | | | | | Two call sites were apparently thinking that the last argument of SPI_execute_plan() is the number of query parameters, but it is actually the row limit. Change the calls to 0, since we don't care about the limit there. The previous code didn't break anything, but it was still wrong.
* Avoid potential buffer overflow crashPeter Eisentraut2013-11-23
| | | | | | | | | | A pointer to a C string was treated as a pointer to a "name" datum and passed to SPI_execute_plan(). This pointer would then end up being passed through datumCopy(), which would try to copy the entire 64 bytes of name data, thus running past the end of the C string. Fix by converting the string to a proper name structure. Found by LLVM AddressSanitizer.
* Support multi-argument UNNEST(), and TABLE() syntax for multiple functions.Tom Lane2013-11-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds the ability to write TABLE( function1(), function2(), ...) as a single FROM-clause entry. The result is the concatenation of the first row from each function, followed by the second row from each function, etc; with NULLs inserted if any function produces fewer rows than others. This is believed to be a much more useful behavior than what Postgres currently does with multiple SRFs in a SELECT list. This syntax also provides a reasonable way to combine use of column definition lists with WITH ORDINALITY: put the column definition list inside TABLE(), where it's clear that it doesn't control the ordinality column as well. Also implement SQL-compliant multiple-argument UNNEST(), by turning UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)). The SQL standard specifies TABLE() with only a single function, not multiple functions, and it seems to require an implicit UNNEST() which is not what this patch does. There may be something wrong with that reading of the spec, though, because if it's right then the spec's TABLE() is just a pointless alternative spelling of UNNEST(). After further review of that, we might choose to adopt a different syntax for what this patch does, but in any case this functionality seems clearly worthwhile. Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and significantly revised by me
* Fix ruleutils pretty-printing to not generate trailing whitespace.Tom Lane2013-11-11
| | | | | | | | | | | | | | | | | | | | The pretty-printing logic in ruleutils.c operates by inserting a newline and some indentation whitespace into strings that are already valid SQL. This naturally results in leaving some trailing whitespace before the newline in many cases; which can be annoying when processing the output with other tools, as complained of by Joe Abbate. We can fix that in a pretty localized fashion by deleting any trailing whitespace before we append a pretty-printing newline. In addition, we have to modify the code inserted by commit 2f582f76b1945929ff07116cd4639747ce9bb8a1 so that we also delete trailing whitespace when transposing items from temporary buffers into the main result string, when a temporary item starts with a newline. This results in rather voluminous changes to the regression test results, but it's easily verified that they are only removal of trailing whitespace. Back-patch to 9.3, because the aforementioned commit resulted in many more cases of trailing whitespace than had occurred in earlier branches.
* Support default arguments and named-argument notation for window functions.Tom Lane2013-11-06
| | | | | | | | | | | | | | | | | | | | | | These things didn't work because the planner omitted to do the necessary preprocessing of a WindowFunc's argument list. Add the few dozen lines of code needed to handle that. Although this sounds like a feature addition, it's really a bug fix because the default-argument case was likely to crash previously, due to lack of checking of the number of supplied arguments in the built-in window functions. It's not a security issue because there's no way for a non-superuser to create a window function definition with defaults that refers to a built-in C function, but nonetheless people might be annoyed that it crashes rather than producing a useful error message. So back-patch as far as the patch applies easily, which turns out to be 9.2. I'll put a band-aid in earlier versions as a separate patch. (Note that these features still don't work for aggregates, and fixing that case will be harder since we represent aggregate arg lists as target lists not bare expression lists. There's no crash risk though because CREATE AGGREGATE doesn't accept defaults, and we reject named-argument notation when parsing an aggregate call.)
* Use appendStringInfoString instead of appendStringInfo where possible.Robert Haas2013-10-31
| | | | | | | This shaves a few cycles, and generally seems like good programming practice. David Rowley
* Eliminate pg_rewrite.ev_attr column and related dead code.Kevin Grittner2013-09-05
| | | | | | | | Commit 95ef6a344821655ce4d0a74999ac49dd6af6d342 removed the ability to create rules on an individual column as of 7.3, but left some residual code which has since been useless. This cleans up that dead code without any change in behavior other than dropping the useless column from the catalog.
* Allow aggregate functions to be VARIADIC.Tom Lane2013-09-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | There's no inherent reason why an aggregate function can't be variadic (even VARIADIC ANY) if its transition function can handle the case. Indeed, this patch to add the feature touches none of the planner or executor, and little of the parser; the main missing stuff was DDL and pg_dump support. It is true that variadic aggregates can create the same sort of ambiguity about parameters versus ORDER BY keys that was complained of when we (briefly) had both one- and two-argument forms of string_agg(). However, the policy formed in response to that discussion only said that we'd not create any built-in aggregates with varying numbers of arguments, not that we shouldn't allow users to do it. So the logical extension of that is we can allow users to make variadic aggregates as long as we're wary about shipping any such in core. In passing, this patch allows aggregate function arguments to be named, to the extent of remembering the names in pg_proc and dumping them in pg_dump. You can't yet call an aggregate using named-parameter notation. That seems like a likely future extension, but it'll take some work, and it's not what this patch is really about. Likewise, there's still some work needed to make window functions handle VARIADIC fully, but I left that for another day. initdb forced because of new aggvariadic field in Aggref parse nodes.
* Add SQL Standard WITH ORDINALITY support for UNNEST (and any other SRF)Greg Stark2013-07-29
| | | | | Author: Andrew Gierth, David Fetter Reviewers: Dean Rasheed, Jeevan Chalke, Stephen Frost
* Move strip_implicit_coercions() from optimizer to nodeFuncs.c.Tom Lane2013-07-23
| | | | | | | | Use of this function has spread into the parser and rewriter, so it seems like time to pull it out of the optimizer and put it into the more central nodeFuncs module. This eliminates the need to #include optimizer/clauses.h in most of the calling files, demonstrating that this function was indeed a bit outside the normal code reference patterns.
* Further hacking on ruleutils' new column-alias-assignment code.Tom Lane2013-07-23
| | | | | | | | | | | | | | | | | After further thought about implicit coercions appearing in a joinaliasvars list, I realized that they represent an additional reason why we might need to reference the join output column directly instead of referencing an underlying column. Consider SELECT x FROM t1 LEFT JOIN t2 USING (x) where t1.x is of type date while t2.x is of type timestamptz. The merged output variable is of type timestamptz, but it won't go to null when t2 does, therefore neither t1.x nor t2.x is a valid substitute reference. The code in get_variable() actually gets this case right, since it knows it shouldn't look through a coercion, but we failed to ensure that the unqualified output column name would be globally unique. To fix, modify the code that trawls for a dangerous situation so that it actually scans through an unnamed join's joinaliasvars list to see if there are any non-simple-Var entries.
* Change post-rewriter representation of dropped columns in joinaliasvars.Tom Lane2013-07-23
| | | | | | | | | | | | | | | | | | | | | It's possible to drop a column from an input table of a JOIN clause in a view, if that column is nowhere actually referenced in the view. But it will still be there in the JOIN clause's joinaliasvars list. We used to replace such entries with NULL Const nodes, which is handy for generation of RowExpr expansion of a whole-row reference to the view. The trouble with that is that it can't be distinguished from the situation after subquery pull-up of a constant subquery output expression below the JOIN. Instead, replace such joinaliasvars with null pointers (empty expression trees), which can't be confused with pulled-up expressions. expandRTE() still emits the old convention, though, for convenience of RowExpr generation and to reduce the risk of breaking extension code. In HEAD and 9.3, this patch also fixes a problem with some new code in ruleutils.c that was failing to cope with implicitly-casted joinaliasvars entries, as per recent report from Feike Steenbergen. That oversight was because of an inadequate description of the data structure in parsenodes.h, which I've now corrected. There were some pre-existing oversights of the same ilk elsewhere, which I believe are now all fixed.
* Move checking an explicit VARIADIC "any" argument into the parser.Andrew Dunstan2013-07-18
| | | | | | | | | This is more efficient and simpler . It does mean that an untyped NULL can no longer be used in such cases, which should be mentioned in Release Notes, but doesn't seem a terrible loss. The workaround is to cast the NULL to some array type. Pavel Stehule, reviewed by Jeevan Chalke.
* Implement the FILTER clause for aggregate function calls.Noah Misch2013-07-16
| | | | | | | | | This is SQL-standard with a few extensions, namely support for subqueries and outer references in clause expressions. catversion bump due to change in Aggref and WindowFunc. David Fetter, reviewed by Dean Rasheed.
* Use an MVCC snapshot, rather than SnapshotNow, for catalog scans.Robert Haas2013-07-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | SnapshotNow scans have the undesirable property that, in the face of concurrent updates, the scan can fail to see either the old or the new versions of the row. In many cases, we work around this by requiring DDL operations to hold AccessExclusiveLock on the object being modified; in some cases, the existing locking is inadequate and random failures occur as a result. This commit doesn't change anything related to locking, but will hopefully pave the way to allowing lock strength reductions in the future. The major issue has held us back from making this change in the past is that taking an MVCC snapshot is significantly more expensive than using a static special snapshot such as SnapshotNow. However, testing of various worst-case scenarios reveals that this problem is not severe except under fairly extreme workloads. To mitigate those problems, we avoid retaking the MVCC snapshot for each new scan; instead, we take a new snapshot only when invalidation messages have been processed. The catcache machinery already requires that invalidation messages be sent before releasing the related heavyweight lock; else other backends might rely on locally-cached data rather than scanning the catalog at all. Thus, making snapshot reuse dependent on the same guarantees shouldn't break anything that wasn't already subtly broken. Patch by me. Review by Michael Paquier and Andres Freund.
* pgindent run for release 9.3Bruce Momjian2013-05-29
| | | | | This is the first run of the Perl-based pgindent script. Also update pgindent instructions.
* Fix crash when trying to display a NOTIFY rule action.Tom Lane2013-05-16
| | | | | | | | Fixes oversight in commit 2ffa740be9d96a3743ecb7e42391c53d0760c65a. Per report from Josh Kupershmidt. I think we've broken this case before, so let's add a regression test this time.
* Perform line wrapping and indenting by default in ruleutils.c.Tom Lane2013-02-03
| | | | | | | | | | | | | | | This patch changes pg_get_viewdef() and allied functions so that PRETTY_INDENT processing is always enabled. Per discussion, only the PRETTY_PAREN processing (that is, stripping of "unnecessary" parentheses) poses any real forward-compatibility risk, so we may as well make dump output look as nice as we safely can. Also, set the default wrap length to zero (i.e, wrap after each SELECT or FROM list item), since there's no very principled argument for the former default of 80-column wrapping, and most people seem to agree this way looks better. Marko Tiikkaja, reviewed by Jeevan Chalke, further hacking by Tom Lane
* Improve concurrency of foreign key lockingAlvaro Herrera2013-01-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch introduces two additional lock modes for tuples: "SELECT FOR KEY SHARE" and "SELECT FOR NO KEY UPDATE". These don't block each other, in contrast with already existing "SELECT FOR SHARE" and "SELECT FOR UPDATE". UPDATE commands that do not modify the values stored in the columns that are part of the key of the tuple now grab a SELECT FOR NO KEY UPDATE lock on the tuple, allowing them to proceed concurrently with tuple locks of the FOR KEY SHARE variety. Foreign key triggers now use FOR KEY SHARE instead of FOR SHARE; this means the concurrency improvement applies to them, which is the whole point of this patch. The added tuple lock semantics require some rejiggering of the multixact module, so that the locking level that each transaction is holding can be stored alongside its Xid. Also, multixacts now need to persist across server restarts and crashes, because they can now represent not only tuple locks, but also tuple updates. This means we need more careful tracking of lifetime of pg_multixact SLRU files; since they now persist longer, we require more infrastructure to figure out when they can be removed. pg_upgrade also needs to be careful to copy pg_multixact files over from the old server to the new, or at least part of multixact.c state, depending on the versions of the old and new servers. Tuple time qualification rules (HeapTupleSatisfies routines) need to be careful not to consider tuples with the "is multi" infomask bit set as being only locked; they might need to look up MultiXact values (i.e. possibly do pg_multixact I/O) to find out the Xid that updated a tuple, whereas they previously were assured to only use information readily available from the tuple header. This is considered acceptable, because the extra I/O would involve cases that would previously cause some commands to block waiting for concurrent transactions to finish. Another important change is the fact that locking tuples that have previously been updated causes the future versions to be marked as locked, too; this is essential for correctness of foreign key checks. This causes additional WAL-logging, also (there was previously a single WAL record for a locked tuple; now there are as many as updated copies of the tuple there exist.) With all this in place, contention related to tuples being checked by foreign key rules should be much reduced. As a bonus, the old behavior that a subtransaction grabbing a stronger tuple lock than the parent (sub)transaction held on a given tuple and later aborting caused the weaker lock to be lost, has been fixed. Many new spec files were added for isolation tester framework, to ensure overall behavior is sane. There's probably room for several more tests. There were several reviewers of this patch; in particular, Noah Misch and Andres Freund spent considerable time in it. Original idea for the patch came from Simon Riggs, after a problem report by Joel Jacobson. Most code is from me, with contributions from Marti Raudsepp, Alexander Shulgin, Noah Misch and Andres Freund. This patch was discussed in several pgsql-hackers threads; the most important start at the following message-ids: AANLkTimo9XVcEzfiBR-ut3KVNDkjm2Vxh+t8kAmWjPuv@mail.gmail.com 1290721684-sup-3951@alvh.no-ip.org 1294953201-sup-2099@alvh.no-ip.org 1320343602-sup-2290@alvh.no-ip.org 1339690386-sup-8927@alvh.no-ip.org 4FE5FF020200002500048A3D@gw.wicourts.gov 4FEAB90A0200002500048B7D@gw.wicourts.gov
* Add infrastructure for storing a VARIADIC ANY function's VARIADIC flag.Tom Lane2013-01-21
| | | | | | | | | | | | | | | | | Originally we didn't bother to mark FuncExprs with any indication whether VARIADIC had been given in the source text, because there didn't seem to be any need for it at runtime. However, because we cannot fold a VARIADIC ANY function's arguments into an array (since they're not necessarily all the same type), we do actually need that information at runtime if VARIADIC ANY functions are to respond unsurprisingly to use of the VARIADIC keyword. Add the missing field, and also fix ruleutils.c so that VARIADIC ANY function calls are dumped properly. Extracted from a larger patch that also fixes concat() and format() (the only two extant VARIADIC ANY functions) to behave properly when VARIADIC is specified. This portion seems appropriate to review and commit separately. Pavel Stehule
* Update copyrights for 2013Bruce Momjian2013-01-01
| | | | | Fully update git head, and update back branches in ./COPYRIGHT and legal.sgml files.
* Fix ruleutils to cope with conflicts from adding/dropping/renaming columns.Tom Lane2012-12-31
| | | | | | | | | | | | | | | | | In commit 11e131854f8231a21613f834c40fe9d046926387, we improved the rule/view dumping code so that it would produce valid query representations even if some of the tables involved in a query had been renamed since the query was parsed. This patch extends that idea to fix problems that occur when individual columns are renamed, or added or dropped. As before, the core of the fix is to assign unique new aliases when a name conflict has been created. This is complicated by the JOIN USING feature, which requires the same column alias to be used in both input relations, but we can handle that with a sufficiently complex approach to assigning aliases. A fortiori, this patch takes care of situations where the query didn't have unique column names to begin with, such as in a recent complaint from Bryan Nuse. (Because of expansion of "SELECT *", re-parsing a dumped query can require column name uniqueness even though the original text did not.)
* Fix some minor issues in view pretty-printing.Tom Lane2012-12-24
| | | | | | | | Code review for commit 2f582f76b1945929ff07116cd4639747ce9bb8a1: don't use a static variable for what ought to be a deparse_context field, fix non-multibyte-safe test for spaces, avoid useless and potentially O(N^2) (though admittedly with a very small constant) calculations of wrap positions when we aren't going to wrap.
* Fix ruleutils to print "INSERT INTO foo DEFAULT VALUES" correctly.Tom Lane2012-10-19
| | | | | Per bug #7615 from Marko Tiikkaja. Apparently nobody ever tried this case before ...
* Fix oversight in new code for printing rangetable aliases.Tom Lane2012-10-12
| | | | | | | | In commit 11e131854f8231a21613f834c40fe9d046926387, I missed the case of a CTE RTE that doesn't have a user-defined alias, but does have an alias assigned by set_rtable_names(). Per report from Peter Eisentraut. While at it, refactor slightly to reduce code duplication.
* 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.
* 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.