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* Fix grammar's AND/OR flattening to work with operator_precedence_warning.Tom Lane2016-06-03
| | | | | | | | | | | | | It'd be good for "(x AND y) AND z" to produce a three-child AND node whether or not operator_precedence_warning is on, but that failed to happen when it's on because makeAndExpr() didn't look through the added AEXPR_PAREN node. This has no effect on generated plans because prepqual.c would flatten the AND nest anyway; but it does affect the number of parens printed in ruleutils.c, for example. I'd already fixed some similar hazards in parse_expr.c in commit abb164655, but didn't think to search gram.y for problems of this ilk. Per gripe from Jean-Pierre Pelletier. Report: <fa0535ec6d6428cfec40c7e8a6d11156@mail.gmail.com>
* Remove option to write USING before opclass name in CREATE INDEX.Tom Lane2016-05-25
| | | | | | | | | | | | | | | | | | | | | | | | | Dating back to commit f10b63923, our grammar has allowed "USING" to optionally appear before an opclass name in CREATE INDEX (and, lately, some related places such as ON CONFLICT specifications). Nikolay Shaplov noticed that this syntax existed but wasn't documented, and proposed documenting it. But what seems like a better idea is to remove the production, thereby making the code match the docs not vice versa. This isn't our usual modus operandi for such cases, but there are a couple of good reasons to proceed this way: * So far as I can find, this syntax has never been documented anywhere. It isn't relied on by any of our own code or test cases, and there seems little reason to suppose that it's been used in the wild either. * Documenting it would mean that there would be two separate uses of USING in the CREATE INDEX syntax, the other being "USING access_method". That can lead to nothing but confusion. So, let's just remove it. On the off chance that somebody somewhere is using it, this isn't something to back-patch, but we can fix it in HEAD. Discussion: <1593237.l7oKHRpxSe@nataraj-amd64>
* Add support for more extensive testing of raw_expression_tree_walker().Tom Lane2016-05-23
| | | | | | | | | | | | | | | | | | | | | If RAW_EXPRESSION_COVERAGE_TEST is defined, do a no-op tree walk over every basic DML statement submitted to parse analysis. If we'd had this in place earlier, bug #14153 would have been caught by buildfarm testing. The difficulty is that raw_expression_tree_walker() is only used in limited cases involving CTEs (particularly recursive ones), so it's very easy for an oversight in it to not be noticed during testing of a seemingly-unrelated feature. The type of error we can expect to catch with this is complete omission of a node type from raw_expression_tree_walker(), and perhaps also recursion into a field that doesn't contain a node tree, though that would be an unlikely mistake. It won't catch failure to add new fields that need to be recursed into, unfortunately. I'll go enable this on one or two of my own buildfarm animals once bug #14153 is dealt with. Discussion: <27861.1464040417@sss.pgh.pa.us>
* Fix unexpected side-effects of operator_precedence_warning.Tom Lane2016-04-21
| | | | | | | | | | | | | | | The implementation of that feature involves injecting nodes into the raw parsetree where explicit parentheses appear. Various places in parse_expr.c that test to see "is this child node of type Foo" need to look through such nodes, else we'll get different behavior when operator_precedence_warning is on than when it is off. Note that we only need to handle this when testing untransformed child nodes, since the AEXPR_PAREN nodes will be gone anyway after transformExprRecurse. Per report from Scott Ribe and additional code-reading. Back-patch to 9.5 where this feature was added. Report: <ED37E303-1B0A-4CD8-8E1E-B9C4C2DD9A17@elevated-dev.com>
* Revert CREATE INDEX ... INCLUDING ...Teodor Sigaev2016-04-08
| | | | | | It's not ready yet, revert two commits 690c543550b0d2852060c18d270cdb534d339d9a - unstable test output 386e3d7609c49505e079c40c65919d99feb82505 - patch itself
* CREATE INDEX ... INCLUDING (column[, ...])Teodor Sigaev2016-04-08
| | | | | | | | | | Now indexes (but only B-tree for now) can contain "extra" column(s) which doesn't participate in index structure, they are just stored in leaf tuples. It allows to use index only scan by using single index instead of two or more indexes. Author: Anastasia Lubennikova with minor editorializing by me Reviewers: David Rowley, Peter Geoghegan, Jeff Janes
* Run pgindent on a batch of (mostly-planner-related) source files.Tom Lane2016-04-06
| | | | | Getting annoyed at the amount of unrelated chatter I get from pgindent'ing Rowley's unique-joins patch. Re-indent all the files it touches.
* Support ALTER THING .. DEPENDS ON EXTENSIONAlvaro Herrera2016-04-05
| | | | | | | | | | | | | | This introduces a new dependency type which marks an object as depending on an extension, such that if the extension is dropped, the object automatically goes away; and also, if the database is dumped, the object is included in the dump output. Currently the grammar supports this for indexes, triggers, materialized views and functions only, although the utility code is generic so adding support for more object types is a matter of touching the parser rules only. Author: Abhijit Menon-Sen Reviewed-by: Alexander Korotkov, Álvaro Herrera Discussion: http://www.postgresql.org/message-id/20160115062649.GA5068@toroid.org
* Type names should not be quotedAlvaro Herrera2016-04-01
| | | | | | | | | Our actual convention, contrary to what I said in 59a2111b23f, is not to quote type names, as evidenced by unquoted use of format_type_be() result value in error messages. Remove quotes from recently tweaked messages accordingly. Per note from Tom Lane
* Allow aggregate transition states to be serialized and deserialized.Robert Haas2016-03-29
| | | | | | | | | This is necessary infrastructure for supporting parallel aggregation for aggregates whose transition type is "internal". Such values can't be passed between cooperating processes, because they are just pointers. David Rowley, reviewed by Tomas Vondra and by me.
* Improve internationalization of messages involving type namesAlvaro Herrera2016-03-28
| | | | | | | | | | | | | | | Change the slightly different variations of the message function FOO must return type BAR to a single wording, removing the variability in type name so that they all create a single translation entry; since the type name is not to be translated, there's no point in it being part of the message anyway. Also, change them all to use the same quoting convention, namely that the function name is not to be quoted but the type name is. (I'm not quite sure why this is so, but it's the clear majority.) Some similar messages such as "encoding conversion function FOO must ..." are also changed.
* Move psql's psqlscan.l into src/fe_utils.Tom Lane2016-03-24
| | | | | | | | | | | This completes (at least for now) the project of getting rid of ad-hoc linkages among the src/bin/ subdirectories. Everything they share is now in src/fe_utils/ and is included from a static library at link time. A side benefit is that we can restore the FLEX_NO_BACKUP check for psqlscanslash.l. We might need to think of another way to do that check if we ever need to build two lexers with that property in the same source directory, but there's no foreseeable reason to need that.
* Support CREATE ACCESS METHODAlvaro Herrera2016-03-23
| | | | | | | | | | | | | | | This enables external code to create access methods. This is useful so that extensions can add their own access methods which can be formally tracked for dependencies, so that DROP operates correctly. Also, having explicit support makes pg_dump work correctly. Currently only index AMs are supported, but we expect different types to be added in the future. Authors: Alexander Korotkov, Petr Jelínek Reviewed-By: Teodor Sigaev, Petr Jelínek, Jim Nasby Commitfest-URL: https://commitfest.postgresql.org/9/353/ Discussion: https://www.postgresql.org/message-id/CAPpHfdsXwZmojm6Dx+TJnpYk27kT4o7Ri6X_4OSWcByu1Rm+VA@mail.gmail.com
* Move keywords.c/kwlookup.c into src/common/.Tom Lane2016-03-23
| | | | | | | | | | | | | | | | | | | Now that we have src/common/ for code shared between frontend and backend, we can get rid of (most of) the klugy ways that the keyword table and keyword lookup code were formerly shared between different uses. This is a first step towards a more general plan of getting rid of special-purpose kluges for sharing code in src/bin/. I chose to merge kwlookup.c back into keywords.c, as it once was, and always has been so far as keywords.h is concerned. We could have kept them separate, but there is noplace that uses ScanKeywordLookup without also wanting access to the backend's keyword list, so there seems little point. ecpg is still a bit weird, but at least now the trickiness is documented. I think that the MSVC build script should require no adjustments beyond what's done here ... but we'll soon find out.
* Support parallel aggregation.Robert Haas2016-03-21
| | | | | | | | | Parallel workers can now partially aggregate the data and pass the transition values back to the leader, which can combine the partial results to produce the final answer. David Rowley, based on earlier work by Haribabu Kommi. Reviewed by Álvaro Herrera, Tomas Vondra, Amit Kapila, James Sewell, and me.
* Sync backend/parser/scan.l with bin/psql/psqlscan.l.Tom Lane2016-03-19
| | | | | | | | | | | | | | Make some minor formatting adjustments to make it easier to diff these files and see that they indeed implement the same flex rules (at least to the extent that we want them to be the same). (Someday it'd be nice to make ecpg's pgc.l more easily diff'able too, but today is not that day.) Also run relevant parts of these files and psqlscanslash.l through pgindent. No actual behavioral changes here, just obsessive neatnik-ism.
* Build backend/parser/scan.l and interfaces/ecpg/preproc/pgc.l standalone.Tom Lane2016-03-19
| | | | | | | | | | | | | Now that we know about the %top{} trick, we can revert to building flex lexers as separate .o files. This is worth doing for a couple of reasons besides sheer cleanliness. We can narrow the scope of the -Wno-error flag that's forced on scan.c. Also, since these grammar and lexer files are so large, splitting them into separate build targets should have some advantages in build speed, particularly in parallel or ccache'd builds. We have quite a few other .l files that could be changed likewise, but the above arguments don't apply to them, so the benefit of fixing them seems pretty minimal. Leave the rest for some other day.
* Introduce parse_ident()Teodor Sigaev2016-03-18
| | | | | | SQL-layer function to split qualified identifier into array parts. Author: Pavel Stehule with minor editorization by me and Jim Nasby
* Fix typos.Robert Haas2016-03-15
| | | | Oskari Saarenmaa
* Refactor pull_var_clause's API to make it less tedious to extend.Tom Lane2016-03-10
| | | | | | | | | | | | | | | | | | | | In commit 1d97c19a0f748e94 and later c1d9579dd8bf3c92, we extended pull_var_clause's API by adding enum-type arguments. That's sort of a pain to maintain, though, because it means every time we add a new behavior we must touch every last one of the call sites, even if there's a reasonable default behavior that most of them could use. Let's switch over to using a bitmask of flags, instead; that seems more maintainable and might save a nanosecond or two as well. This commit changes no behavior in itself, though I'm going to follow it up with one that does add a new behavior. In passing, remove flatten_tlist(), which has not been used since 9.1 and would otherwise need the same API changes. Removing these enums means that optimizer/tlist.h no longer needs to depend on optimizer/var.h. Changing that caused a number of C files to need addition of #include "optimizer/var.h" (probably we can thank old runs of pgrminclude for that); but on balance it seems like a good change anyway.
* Fix copy-and-pasteo in comment.Tom Lane2016-03-09
| | | | Wensheng Zhang
* Move pg_constraint.h function declarations to new file pg_constraint_fn.h.Tom Lane2016-02-11
| | | | | | | | | | | A pending patch requires exporting a function returning Bitmapset from catalog/pg_constraint.c. As things stand, that would mean including nodes/bitmapset.h in pg_constraint.h, which might be hazardous for the client-side includability of that header. It's not entirely clear whether any client-side code needs to include pg_constraint.h, but it seems prudent to assume that there is some such code somewhere. Therefore, split off the function definitions into a new file pg_constraint_fn.h, similarly to what we've done for some other catalog header files.
* Remove new coupling between NAMEDATALEN and MAX_LEVENSHTEIN_STRLEN.Tom Lane2016-01-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | Commit e529cd4ffa605c6f introduced an Assert requiring NAMEDATALEN to be less than MAX_LEVENSHTEIN_STRLEN, which has been 255 for a long time. Since up to that instant we had always allowed NAMEDATALEN to be substantially more than that, this was ill-advised. It's debatable whether we need MAX_LEVENSHTEIN_STRLEN at all (versus putting a CHECK_FOR_INTERRUPTS into the loop), or whether it has to be so tight; but this patch takes the narrower approach of just not applying the MAX_LEVENSHTEIN_STRLEN limit to calls from the parser. Trusting the parser for this seems reasonable, first because the strings are limited to NAMEDATALEN which is unlikely to be hugely more than 256, and second because the maximum distance is tightly constrained by MAX_FUZZY_DISTANCE (though we'd forgotten to make use of that limit in one place). That means the cost is not really O(mn) but more like O(max(m,n)). Relaxing the limit for user-supplied calls is left for future research; given the lack of complaints to date, it doesn't seem very high priority. In passing, fix confusion between lengths-in-bytes and lengths-in-chars in comments and error messages. Per gripe from Kevin Day; solution suggested by Robert Haas. Back-patch to 9.5 where the unwanted restriction was introduced.
* Add defenses against putting expanded objects into Const nodes.Tom Lane2016-01-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Putting a reference to an expanded-format value into a Const node would be a bad idea for a couple of reasons. It'd be possible for the supposedly immutable Const to change value, if something modified the referenced variable ... in fact, if the Const's reference were R/W, any function that has the Const as argument might itself change it at runtime. Also, because datumIsEqual() is pretty simplistic, the Const might fail to compare equal to other Consts that it should compare equal to, notably including copies of itself. This could lead to unexpected planner behavior, such as "could not find pathkey item to sort" errors or inferior plans. I have not been able to find any way to get an expanded value into a Const within the existing core code; but Paul Ramsey was able to trigger the problem by writing a datatype input function that returns an expanded value. The best fix seems to be to establish a rule that varlena values being placed into Const nodes should be passed through pg_detoast_datum(). That will do nothing (and cost little) in normal cases, but it will flatten expanded values and thereby avoid the above problems. Also, it will convert short-header or compressed values into canonical format, which will avoid possible unexpected lack-of-equality issues for those cases too. And it provides a last-ditch defense against putting a toasted value into a Const, which we already knew was dangerous, cf commit 2b0c86b66563cf2f. (In the light of this discussion, I'm no longer sure that that commit provided 100% protection against such cases, but this fix should do it.) The test added in commit 65c3d05e18e7c530 to catch datatype input functions with unstable results would fail for functions that returned expanded values; but it seems a bit uncharitable to deem a result unstable just because it's expressed in expanded form, so revise the coding so that we check for bitwise equality only after applying pg_detoast_datum(). That's a sufficient condition anyway given the new rule about detoasting when forming a Const. Back-patch to 9.5 where the expanded-object facility was added. It's possible that this should go back further; but in the absence of clear evidence that there's any live bug in older branches, I'll refrain for now.
* Support multi-stage aggregation.Robert Haas2016-01-20
| | | | | | | | | | | | | | | | | | | Aggregate nodes now have two new modes: a "partial" mode where they output the unfinalized transition state, and a "finalize" mode where they accept unfinalized transition states rather than individual values as input. These new modes are not used anywhere yet, but they will be necessary for parallel aggregation. The infrastructure also figures to be useful for cases where we want to aggregate local data and remote data via the FDW interface, and want to bring back partial aggregates from the remote side that can then be combined with locally generated partial aggregates to produce the final value. It may also be useful even when neither FDWs nor parallelism are in play, as explained in the comments in nodeAgg.c. David Rowley and Simon Riggs, reviewed by KaiGai Kohei, Heikki Linnakangas, Haribabu Kommi, and me.
* Restructure index access method API to hide most of it at the C level.Tom Lane2016-01-17
| | | | | | | | | | | | | | | | | | | | | | | | This patch reduces pg_am to just two columns, a name and a handler function. All the data formerly obtained from pg_am is now provided in a C struct returned by the handler function. This is similar to the designs we've adopted for FDWs and tablesample methods. There are multiple advantages. For one, the index AM's support functions are now simple C functions, making them faster to call and much less error-prone, since the C compiler can now check function signatures. For another, this will make it far more practical to define index access methods in installable extensions. A disadvantage is that SQL-level code can no longer see attributes of index AMs; in particular, some of the crosschecks in the opr_sanity regression test are no longer possible from SQL. We've addressed that by adding a facility for the index AM to perform such checks instead. (Much more could be done in that line, but for now we're content if the amvalidate functions more or less replace what opr_sanity used to do.) We might also want to expose some sort of reporting functionality, but this patch doesn't do that. Alexander Korotkov, reviewed by Petr Jelínek, and rather heavily editorialized on by me.
* Update copyright for 2016Bruce Momjian2016-01-02
| | | | Backpatch certain files through 9.1
* Allow omitting one or both boundaries in an array slice specifier.Tom Lane2015-12-22
| | | | | | | | | | Omitted boundaries represent the upper or lower limit of the corresponding array subscript. This allows simpler specification of many common use-cases. (Revised version of commit 9246af6799819847faa33baf441251003acbb8fe) YUriy Zhuravlev
* Revert 9246af6799819847faa33baf441251003acbb8fe becauseTeodor Sigaev2015-12-18
| | | | I miss too much. Patch is returned to commitfest process.
* Allow to omit boundaries in array subscriptTeodor Sigaev2015-12-18
| | | | | | | Allow to omiy lower or upper or both boundaries in array subscript for selecting slice of array. Author: YUriy Zhuravlev
* Mark CHECK constraints declared NOT VALID valid if created with table.Robert Haas2015-12-16
| | | | | | | | FOREIGN KEY constraints have behaved this way for a long time, but for some reason the behavior of CHECK constraints has been inconsistent up until now. Amit Langote and Amul Sul, with assorted tweaks by me.
* COPY (INSERT/UPDATE/DELETE .. RETURNING ..)Teodor Sigaev2015-11-27
| | | | | | | Attached is a patch for being able to do COPY (query) without a CTE. Author: Marko Tiikkaja Review: Michael Paquier
* Message improvementsPeter Eisentraut2015-11-16
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* Message style improvementsPeter Eisentraut2015-10-28
| | | | | Message style, plurals, quoting, spelling, consistency with similar messages
* Fix typos in comments.Robert Haas2015-10-22
| | | | CharSyam
* Remove redundant CREATEUSER/NOCREATEUSER options in CREATE ROLE et al.Tom Lane2015-10-22
| | | | | | | | | | | | Once upon a time we did not have a separate CREATEROLE privilege, and CREATEUSER effectively meant SUPERUSER. When we invented CREATEROLE (in 8.1) we also added SUPERUSER so as to have a less confusing keyword for this role property. However, we left CREATEUSER in place as a deprecated synonym for SUPERUSER, because of backwards-compatibility concerns. It's still there and is still confusing people, as for example in bug #13694 from Justin Catterson. 9.6 will be ten years or so later, which surely ought to be long enough to end the deprecation and just remove these old keywords. Hence, do so.
* Have CREATE TABLE LIKE add OID column if any LIKEd table has oneBruce Momjian2015-10-05
| | | | | | | Also, process constraints for LIKEd tables at the end so an OID column can be referenced in a constraint. Report by Tom Lane
* ALTER TABLE .. FORCE ROW LEVEL SECURITYStephen Frost2015-10-04
| | | | | | | | | | | | | | | | | To allow users to force RLS to always be applied, even for table owners, add ALTER TABLE .. FORCE ROW LEVEL SECURITY. row_security=off overrides FORCE ROW LEVEL SECURITY, to ensure pg_dump output is complete (by default). Also add SECURITY_NOFORCE_RLS context to avoid data corruption when ALTER TABLE .. FORCE ROW SECURITY is being used. The SECURITY_NOFORCE_RLS security context is used only during referential integrity checks and is only considered in check_enable_rls() after we have already checked that the current user is the owner of the relation (which should always be the case during referential integrity checks). Back-patch to 9.5 where RLS was added.
* Add CASCADE support for CREATE EXTENSION.Andres Freund2015-10-03
| | | | | | | | | | | | | | | Without CASCADE, if an extension has an unfullfilled dependency on another extension, CREATE EXTENSION ERRORs out with "required extension ... is not installed". That is annoying, especially when that dependency is an implementation detail of the extension, rather than something the extension's user can make sense of. In addition to CASCADE this also includes a small set of regression tests around CREATE EXTENSION. Author: Petr Jelinek, editorialized by Michael Paquier, Andres Freund Reviewed-By: Michael Paquier, Andres Freund, Jeff Janes Discussion: 557E0520.3040800@2ndquadrant.com
* Fix several bugs related to ON CONFLICT's EXCLUDED pseudo relation.Andres Freund2015-10-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Four related issues: 1) attnos/varnos/resnos for EXCLUDED were out of sync when a column after one dropped in the underlying relation was referenced. 2) References to whole-row variables (i.e. EXCLUDED.*) lead to errors. 3) It was possible to reference system columns in the EXCLUDED pseudo relations, even though they would not have valid contents. 4) References to EXCLUDED were rewritten by the RLS machinery, as EXCLUDED was treated as if it were the underlying relation. To fix the first two issues, generate the excluded targetlist with dropped columns in mind and add an entry for whole row variables. Instead of unconditionally adding a wholerow entry we could pull up the expression if needed, but doing it unconditionally seems simpler. The wholerow entry is only really needed for ruleutils/EXPLAIN support anyway. The remaining two issues are addressed by changing the EXCLUDED RTE to have relkind = composite. That fits with EXCLUDED not actually being a real relation, and allows to treat it differently in the relevant places. scanRTEForColumn now skips looking up system columns when the RTE has a composite relkind; fireRIRrules() already had a corresponding check, thereby preventing RLS expansion on EXCLUDED. Also add tests for these issues, and improve a few comments around excluded handling in setrefs.c. Reported-By: Peter Geoghegan, Geoff Winkless Author: Andres Freund, Amit Langote, Peter Geoghegan Discussion: CAEzk6fdzJ3xYQZGbcuYM2rBd2BuDkUksmK=mY9UYYDugg_GgZg@mail.gmail.com, CAM3SWZS+CauzbiCEcg-GdE6K6ycHE_Bz6Ksszy8AoixcMHOmsA@mail.gmail.com Backpatch: 9.5, where ON CONFLICT was introduced
* Determine whether it's safe to attempt a parallel plan for a query.Robert Haas2015-09-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 924bcf4f16d54c55310b28f77686608684734f42 introduced a framework for parallel computation in PostgreSQL that makes most but not all built-in functions safe to execute in parallel mode. In order to have parallel query, we'll need to be able to determine whether that query contains functions (either built-in or user-defined) that cannot be safely executed in parallel mode. This requires those functions to be labeled, so this patch introduces an infrastructure for that. Some functions currently labeled as safe may need to be revised depending on how pending issues related to heavyweight locking under paralllelism are resolved. Parallel plans can't be used except for the case where the query will run to completion. If portal execution were suspended, the parallel mode restrictions would need to remain in effect during that time, but that might make other queries fail. Therefore, this patch introduces a framework that enables consideration of parallel plans only when it is known that the plan will be run to completion. This probably needs some refinement; for example, at bind time, we do not know whether a query run via the extended protocol will be execution to completion or run with a limited fetch count. Having the client indicate its intentions at bind time would constitute a wire protocol break. Some contexts in which parallel mode would be safe are not adjusted by this patch; the default is not to try parallel plans except from call sites that have been updated to say that such plans are OK. This commit doesn't introduce any parallel paths or plans; it just provides a way to determine whether they could potentially be used. I'm committing it on the theory that the remaining parallel sequential scan patches will also get committed to this release, hopefully in the not-too-distant future. Robert Haas and Amit Kapila. Reviewed (in earlier versions) by Noah Misch.
* Rename 'cmd' to 'cmd_name' in CreatePolicyStmtStephen Frost2015-08-21
| | | | | | | | | | | To avoid confusion, rename CreatePolicyStmt's 'cmd' to 'cmd_name', parse_policy_command's 'cmd' to 'polcmd', and AlterPolicy's 'cmd_datum' to 'polcmd_datum', per discussion with Noah and as a follow-up to his correction of copynodes/equalnodes handling of the CreatePolicyStmt 'cmd' field. Back-patch to 9.5 where the CreatePolicyStmt was introduced, as we are still only in alpha.
* Remove gram.y's precedence declaration for OVERLAPS.Tom Lane2015-08-09
| | | | | | | | | | | | | | | | | The allowed syntax for OVERLAPS, viz "row OVERLAPS row", is sufficiently constrained that we don't actually need a precedence declaration for OVERLAPS; indeed removing this declaration does not change the generated gram.c file at all. Let's remove it to avoid confusion about whether OVERLAPS has precedence or not. If we ever generalize what we allow for OVERLAPS, we might need to put back a precedence declaration for it, but we might want some other level than what it has today --- and leaving the declaration there would just risk confusion about whether that would be an incompatible change. Likewise, remove OVERLAPS from the documentation's precedence table. Per discussion with Noah Misch. Back-patch to 9.5 where we hacked up some nearby precedence decisions.
* Share transition state between different aggregates when possible.Heikki Linnakangas2015-08-04
| | | | | | | | | | | | If there are two different aggregates in the query with same inputs, and the aggregates have the same initial condition and transition function, only calculate the state value once, and only call the final functions separately. For example, AVG(x) and SUM(x) aggregates have the same transition function, which accumulates the sum and number of input tuples. For a query like "SELECT AVG(x), SUM(x) FROM x", we can therefore accumulate the state function only once, which gives a nice speedup. David Rowley, reviewed and edited by me.
* Add IF NOT EXISTS processing to ALTER TABLE ADD COLUMNAndrew Dunstan2015-07-29
| | | | | Fabrízio de Royes Mello, reviewed by Payal Singh, Alvaro Herrera and Michael Paquier.
* Create new ParseExprKind for use by policy expressions.Joe Conway2015-07-29
| | | | | | | | | | | Policy USING and WITH CHECK expressions were using EXPR_KIND_WHERE for parse analysis, which results in inappropriate ERROR messages when the expression contains unsupported constructs such as aggregates. Create a new ParseExprKind called EXPR_KIND_POLICY and tailor the related messages to fit. Reported by Noah Misch. Reviewed by Dean Rasheed, Alvaro Herrera, and Robert Haas. Back-patch to 9.5 where RLS was introduced.
* Fix flattening of nested grouping sets.Andres Freund2015-07-26
| | | | | | | | | | | | | | | Previously nested grouping set specifications accidentally weren't flattened, but instead contained the nested specification as a element in the outer list. Fix this by, as actually documented in comments, concatenating the nested set specification into the outer one. Also add tests to prevent this from breaking again. Author: Andrew Gierth, with tests from Jeevan Chalke Reported-By: Jeevan Chalke Discussion: CAM2+6=V5YvuxB+EyN4iH=GbD-XTA435TCNvnDFSD--YvXs+pww@mail.gmail.com Backpatch: 9.5, where grouping sets were introduced
* Redesign tablesample method API, and do extensive code review.Tom Lane2015-07-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | The original implementation of TABLESAMPLE modeled the tablesample method API on index access methods, which wasn't a good choice because, without specialized DDL commands, there's no way to build an extension that can implement a TSM. (Raw inserts into system catalogs are not an acceptable thing to do, because we can't undo them during DROP EXTENSION, nor will pg_upgrade behave sanely.) Instead adopt an API more like procedural language handlers or foreign data wrappers, wherein the only SQL-level support object needed is a single handler function identified by having a special return type. This lets us get rid of the supporting catalog altogether, so that no custom DDL support is needed for the feature. Adjust the API so that it can support non-constant tablesample arguments (the original coding assumed we could evaluate the argument expressions at ExecInitSampleScan time, which is undesirable even if it weren't outright unsafe), and discourage sampling methods from looking at invisible tuples. Make sure that the BERNOULLI and SYSTEM methods are genuinely repeatable within and across queries, as required by the SQL standard, and deal more honestly with methods that can't support that requirement. Make a full code-review pass over the tablesample additions, and fix assorted bugs, omissions, infelicities, and cosmetic issues (such as failure to put the added code stanzas in a consistent ordering). Improve EXPLAIN's output of tablesample plans, too. Back-patch to 9.5 so that we don't have to support the original API in production.
* Fix bug around assignment expressions containing indirections.Andres Freund2015-07-24
| | | | | | | | | | | | | | | | | | Handling of assigned-to expressions with indirection (e.g. set f1[1] = 3) was broken for ON CONFLICT DO UPDATE. The problem was that ParseState was consulted to determine if an INSERT-appropriate or UPDATE-appropriate behavior should be used when transforming expressions with indirections. When the wrong path was taken the old row was substituted with NULL, leading to wrong results.. To fix remove p_is_update and only use p_is_insert to decide how to transform the assignment expression, and uset p_is_insert while parsing the on conflict statement. This isn't particularly pretty, but it's not any worse than before. Author: Peter Geoghegan, slightly edited by me Discussion: CAM3SWZS8RPvA=KFxADZWw3wAHnnbxMxDzkEC6fNaFc7zSm411w@mail.gmail.com Backpatch: 9.5, where the feature was introduced
* Add ALTER OPERATOR command, for changing selectivity estimator functions.Heikki Linnakangas2015-07-14
| | | | | | | | | Other options cannot be changed, as it's not totally clear if cached plans would need to be invalidated if one of the other options change. Selectivity estimator functions only change plan costs, not correctness of plans, so those should be safe. Original patch by Uriy Zhuravlev, heavily edited by me.