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* 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
* Remove unnecessary escaping in C character literalsPeter Eisentraut2015-12-22
| | | | '\"' is more commonly written simply as '"'.
* 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
* Get rid of the planner's LateralJoinInfo data structure.Tom Lane2015-12-11
| | | | | | | | | | | | | | | | | | | | I originally modeled this data structure on SpecialJoinInfo, but after commit acfcd45cacb6df23 that looks like a pretty poor decision. All we really need is relid sets identifying laterally-referenced rels; and most of the time, what we want to know about includes indirect lateral references, a case the LateralJoinInfo data was unsuited to compute with any efficiency. The previous commit redefined RelOptInfo.lateral_relids as the transitive closure of lateral references, so that it easily supports checking indirect references. For the places where we really do want just direct references, add a new RelOptInfo field direct_lateral_relids, which is easily set up as a copy of lateral_relids before we perform the transitive closure calculation. Then we can just drop lateral_info_list and LateralJoinInfo and the supporting code. This makes the planner's handling of lateral references noticeably more efficient, and shorter too. Such a change can't be back-patched into stable branches for fear of breaking extensions that might be looking at the planner's data structures; but it seems not too late to push it into 9.5, so I've done so.
* Allow foreign and custom joins to handle EvalPlanQual rechecks.Robert Haas2015-12-08
| | | | | | | | | | | | | | | | | | | | | | | Commit e7cb7ee14555cc9c5773e2c102efd6371f6f2005 provided basic infrastructure for allowing a foreign data wrapper or custom scan provider to replace a join of one or more tables with a scan. However, this infrastructure failed to take into account the need for possible EvalPlanQual rechecks, and ExecScanFetch would fail an assertion (or just overwrite memory) if such a check was attempted for a plan containing a pushed-down join. To fix, adjust the EPQ machinery to skip some processing steps when scanrelid == 0, making those the responsibility of scan's recheck method, which also has the responsibility in this case of correctly populating the relevant slot. To allow foreign scans to gain control in the right place to make use of this new facility, add a new, optional RecheckForeignScan method. Also, allow a foreign scan to have a child plan, which can be used to correctly populate the slot (or perhaps for something else, but this is the only use currently envisioned). KaiGai Kohei, reviewed by Robert Haas, Etsuro Fujita, and Kyotaro Horiguchi.
* Simplify LATERAL-related calculations within add_paths_to_joinrel().Tom Lane2015-12-07
| | | | | | | | | | | | | | | | | While convincing myself that commit 7e19db0c09719d79 would solve both of the problems recently reported by Andreas Seltenreich, I realized that add_paths_to_joinrel's handling of LATERAL restrictions could be made noticeably simpler and faster if we were to retain the minimum possible parameterization for each joinrel (that is, the set of relids supplying unsatisfied lateral references in it). We already retain that for baserels, in RelOptInfo.lateral_relids, so we can use that field for joinrels too. I re-pgindent'd the files touched here, which affects some unrelated comments. This is, I believe, just a minor optimization not a bug fix, so no back-patch.
* Provide readfuncs support for custom scans.Robert Haas2015-11-12
| | | | | | | | | | Commit a0d9f6e434bb56f7e5441b7988f3982feead33b3 added this support for all other plan node types; this fills in the gap. Since TextOutCustomScan complicates this and is pretty well useless, remove it. KaiGai Kohei, with some modifications by me.
* Generate parallel sequential scan plans in simple cases.Robert Haas2015-11-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a new flag, consider_parallel, to each RelOptInfo, indicating whether a plan for that relation could conceivably be run inside of a parallel worker. Right now, we're pretty conservative: for example, it might be possible to defer applying a parallel-restricted qual in a worker, and later do it in the leader, but right now we just don't try to parallelize access to that relation. That's probably the right decision in most cases, anyway. Using the new flag, generate parallel sequential scan plans for plain baserels, meaning that we now have parallel sequential scan in PostgreSQL. The logic here is pretty unsophisticated right now: the costing model probably isn't right in detail, and we can't push joins beneath Gather nodes, so the number of plans that can actually benefit from this is pretty limited right now. Lots more work is needed. Nevertheless, it seems time to enable this functionality so that all this code can actually be tested easily by users and developers. Note that, if you wish to test this functionality, it will be necessary to set max_parallel_degree to a value greater than the default of 0. Once a few more loose ends have been tidied up here, we might want to consider changing the default value of this GUC, but I'm leaving it alone for now. Along the way, fix a bug in cost_gather: the previous coding thought that a Gather node's transfer overhead should be costed on the basis of the relation size rather than the number of tuples that actually need to be passed off to the leader. Patch by me, reviewed in earlier versions by Amit Kapila.
* Make sequential scans parallel-aware.Robert Haas2015-11-11
| | | | | | | | | | | | | | In addition, this path fills in a number of missing bits and pieces in the parallel infrastructure. Paths and plans now have a parallel_aware flag indicating whether whatever parallel-aware logic they have should be engaged. It is believed that we will need this flag for a number of path/plan types, not just sequential scans, which is why the flag is generic rather than part of the SeqScan structures specifically. Also, execParallel.c now gives parallel nodes a chance to initialize their PlanState nodes from the DSM during parallel worker startup. Amit Kapila, with a fair amount of adjustment by me. Review of previous patch versions by Haribabu Kommi and others.
* Add outfuncs.c support for GatherPath.Robert Haas2015-11-11
| | | | | I dunno how commit 3bd909b220930f21d6e15833a17947be749e7fde missed this, but it evidently did.
* Fix problems with ParamListInfo serialization mechanism.Robert Haas2015-11-02
| | | | | | | | | | | | | | | | | | | | | | Commit d1b7c1ffe72e86932b5395f29e006c3f503bc53d introduced a mechanism for serializing a ParamListInfo structure to be passed to a parallel worker. However, this mechanism failed to handle external expanded values, as pointed out by Noah Misch. Repair. Moreover, plpgsql_param_fetch requires adjustment because the serialization mechanism needs it to skip evaluating unused parameters just as we would do when it is called from copyParamList, but params == estate->paramLI in that case. To fix, make the bms_is_member test in that function unconditional. Finally, have setup_param_list set a new ParamListInfo field, paramMask, to the parameters actually used in the expression, so that we don't try to fetch those that are not needed when serializing a parameter list. This isn't necessary for correctness, but it makes the performance of the parallel executor code comparable to what we do for cases involving cursors. Design suggestions and extensive review by Noah Misch. Patch by me.
* Allow FDWs to push down quals without breaking EvalPlanQual rechecks.Robert Haas2015-10-15
| | | | | | | | | | | | | | | | | This fixes a long-standing bug which was discovered while investigating the interaction between the new join pushdown code and the EvalPlanQual machinery: if a ForeignScan appears on the inner side of a paramaterized nestloop, an EPQ recheck would re-return the original tuple even if it no longer satisfied the pushed-down quals due to changed parameter values. This fix adds a new member to ForeignScan and ForeignScanState and a new argument to make_foreignscan, and requires changes to FDWs which push down quals to populate that new argument with a list of quals they have chosen to push down. Therefore, I'm only back-patching to 9.5, even though the bug is not new in 9.5. Etsuro Fujita, reviewed by me and by Kyotaro Horiguchi.
* Do not write out WCOs in QueryStephen Frost2015-10-05
| | | | | | | | | | The WithCheckOptions list in Query are only populated during rewrite and do not need to be written out or read in as part of a Query structure. Further, move WithCheckOptions to the bottom and add comments to clarify that it is only populated during rewrite. Back-patch to 9.5 with a catversion bump, as we are still in alpha.
* Fix readfuncs/outfuncs problems in last night's Gather patch.Robert Haas2015-10-01
| | | | KaiGai Kohei, with one correction by me.
* Add a Gather executor node.Robert Haas2015-09-30
| | | | | | | | | | | | | | | | | | | | | | | | A Gather executor node runs any number of copies of a plan in an equal number of workers and merges all of the results into a single tuple stream. It can also run the plan itself, if the workers are unavailable or haven't started up yet. It is intended to work with the Partial Seq Scan node which will be added in future commits. It could also be used to implement parallel query of a different sort by itself, without help from Partial Seq Scan, if the single_copy mode is used. In that mode, a worker executes the plan, and the parallel leader does not, merely collecting the worker's results. So, a Gather node could be inserted into a plan to split the execution of that plan across two processes. Nested Gather nodes aren't currently supported, but we might want to add support for that in the future. There's nothing in the planner to actually generate Gather nodes yet, so it's not quite time to break out the champagne. But we're getting close. Amit Kapila. Some designs suggestions were provided by me, and I also reviewed the patch. Single-copy mode, documentation, and other minor changes also by me.
* Parallel executor support.Robert Haas2015-09-28
| | | | | | | | | | | | | This code provides infrastructure for a parallel leader to start up parallel workers to execute subtrees of the plan tree being executed in the master. User-supplied parameters from ParamListInfo are passed down, but PARAM_EXEC parameters are not. Various other constructs, such as initplans, subplans, and CTEs, are also not currently shared. Nevertheless, there's enough here to support a basic implementation of parallel query, and we can lift some of the current restrictions as needed. Amit Kapila and Robert Haas
* Don't zero opfuncid when reading nodes.Robert Haas2015-09-24
| | | | | | | | | | | | | | The comments here stated that this was just in case we ever had an ALTER OPERATOR command that could remap an operator to a different function. But those comments have been here for a long time, and no such command has come about. In the absence of such a feature, forcing the pg_proc OID to be looked up again each time we reread a stored rule or similar is just a waste of cycles. Moreover, parallel query needs a way to reread the exact same node tree that was written out, not one that has been slightly stomped on. So just get rid of this for now. Per discussion with Tom Lane.
* Add readfuncs.c support for plan nodes.Robert Haas2015-09-23
| | | | | | | | | | | | | | | | For parallel query, we need to be able to pass a Plan to a worker, so that it knows what it's supposed to do. We could invent our own way of serializing plans for that purpose, but piggybacking on the existing node infrastructure seems like a much better idea. Initially, we'll probably only support a limited number of nodes within parallel workers, but this commit adds support for everything in plannodes.h except CustomScan, because doing it all at once seems easier than doing it piecemeal, and it makes testing this code easier, too. CustomScan is excluded because making that work requires a larger rework of that facility. Amit Kapila, reviewed and slightly revised by me.
* Print a MergeJoin's mergeNullsFirst array as bool, not int.Robert Haas2015-09-23
| | | | | | | | | It's declared as being an array of bool, but it's printed differently from the way bool and arrays of bool are handled elsewhere. Patch by Amit Kapila. Anomaly noted independently by Amit Kapila and KaiGai Kohei.
* Teach planstate_tree_walker about custom scans.Robert Haas2015-09-22
| | | | | | | | This logic was missing from ExplainPreScanNode, from which I derived planstate_tree_walker. But it shouldn't be missing, especially not from a generic walker function, so add it. KaiGai Kohei
* Add new function planstate_tree_walker.Robert Haas2015-09-17
| | | | | | | | | ExplainPreScanNode knows how to iterate over a generic tree of plan states; factor that logic out into a separate walker function so that other code, such as upcoming patches for parallel query, can also use it. Patch by me, reviewed by Tom Lane.
* 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.
* RLS refactoringStephen Frost2015-09-15
| | | | | | | | | | | | | | | | This refactors rewrite/rowsecurity.c to simplify the handling of the default deny case (reducing the number of places where we check for and add the default deny policy from three to one) by splitting up the retrival of the policies from the application of them. This also allowed us to do away with the policy_id field. A policy_name field was added for WithCheckOption policies and is used in error reporting, when available. Patch by Dean Rasheed, with various mostly cosmetic changes by me. Back-patch to 9.5 where RLS was introduced to avoid unnecessary differences, since we're still in alpha, per discussion with Robert.
* 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.
* Postpone extParam/allParam calculations until the very end of planning.Tom Lane2015-08-11
| | | | | | | | | | | | | | | | | | | | | | | | Until now we computed these Param ID sets at the end of subquery_planner, but that approach depends on subquery_planner returning a concrete Plan tree. We would like to switch over to returning one or more Paths for a subquery, and in that representation the necessary details aren't fully fleshed out (not to mention that we don't really want to do this work for Paths that end up getting discarded). Hence, refactor so that we can compute the param ID sets at the end of planning, just before set_plan_references is run. The main change necessary to make this work is that we need to capture the set of outer-level Param IDs available to the current query level before exiting subquery_planner, since the outer levels' plan_params lists are transient. (That's not going to pose a problem for returning Paths, since all the work involved in producing that data is part of expression preprocessing, which will continue to happen before Paths are produced.) On the plus side, this change gets rid of several existing kluges. Eventually I'd like to get rid of SS_finalize_plan altogether in favor of doing this work during set_plan_references, but that will require some complex rejiggering because SS_finalize_plan needs to visit subplans and initplans before the main plan. So leave that idea for another day.
* Reconcile nodes/*funcs.c with recent work.Noah Misch2015-08-05
| | | | | | | | | A few of the discrepancies had semantic significance, but I did not track down the resulting user-visible bugs, if any. Back-patch to 9.5, where all but one discrepancy appeared. The _equalCreateEventTrigStmt() situation dates to 9.3 but does not affect semantics. catversion bump due to readfuncs.c field order changes.
* Rely on inline functions even if that causes warnings in older compilers.Andres Freund2015-08-05
| | | | | | | | | | | | | | | | | | | | | | | | | So far we have worked around the fact that some very old compilers do not support 'inline' functions by only using inline functions conditionally (or not at all). Since such compilers are very rare by now, we have decided to rely on inline functions from 9.6 onwards. To avoid breaking these old compilers inline is defined away when not supported. That'll cause "function x defined but not used" type of warnings, but since nobody develops on such compilers anymore that's ok. This change in policy will allow us to more easily employ inline functions. I chose to remove code previously conditional on PG_USE_INLINE as it seemed confusing to have code dependent on a define that's always defined. Blacklisting of compilers, like in c53f73879f, now has to be done differently. A platform template can define PG_FORCE_DISABLE_INLINE to force inline to be defined empty. Discussion: 20150701161447.GB30708@awork2.anarazel.de
* 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.
* 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.
* Fix bogus range_table_mutator() logic for RangeTblEntry.tablesample.Tom Lane2015-06-19
| | | | | | | Must make a copy of the TableSampleClause node; the previous coding modified the input data structure in-place. Petr Jelinek
* Fix planner's cost estimation for SEMI/ANTI joins with inner indexscans.Tom Lane2015-06-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When the inner side of a nestloop SEMI or ANTI join is an indexscan that uses all the join clauses as indexquals, it can be presumed that both matched and unmatched outer rows will be processed very quickly: for matched rows, we'll stop after fetching one row from the indexscan, while for unmatched rows we'll have an indexscan that finds no matching index entries, which should also be quick. The planner already knew about this, but it was nonetheless charging for at least one full run of the inner indexscan, as a consequence of concerns about the behavior of materialized inner scans --- but those concerns don't apply in the fast case. If the inner side has low cardinality (many matching rows) this could make an indexscan plan look far more expensive than it actually is. To fix, rearrange the work in initial_cost_nestloop/final_cost_nestloop so that we don't add the inner scan cost until we've inspected the indexquals, and then we can add either the full-run cost or just the first tuple's cost as appropriate. Experimentation with this fix uncovered another problem: add_path and friends were coded to disregard cheap startup cost when considering parameterized paths. That's usually okay (and desirable, because it thins the path herd faster); but in this fast case for SEMI/ANTI joins, it could result in throwing away the desired plain indexscan path in favor of a bitmap scan path before we ever get to the join costing logic. In the many-matching-rows cases of interest here, a bitmap scan will do a lot more work than required, so this is a problem. To fix, add a per-relation flag consider_param_startup that works like the existing consider_startup flag, but applies to parameterized paths, and set it for relations that are the inside of a SEMI or ANTI join. To make this patch reasonably safe to back-patch, care has been taken to avoid changing the planner's behavior except in the very narrow case of SEMI/ANTI joins with inner indexscans. There are places in compare_path_costs_fuzzily and add_path_precheck that are not terribly consistent with the new approach, but changing them will affect planner decisions at the margins in other cases, so we'll leave that for a HEAD-only fix. Back-patch to 9.3; before that, the consider_startup flag didn't exist, meaning that the second aspect of the patch would be too invasive. Per a complaint from Peter Holzer and analysis by Tomas Vondra.
* pgindent run for 9.5Bruce Momjian2015-05-23
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* Remove the new UPSERT command tag and use INSERT instead.Andres Freund2015-05-23
| | | | | | | | | | | | | | | | | Previously, INSERT with ON CONFLICT DO UPDATE specified used a new command tag -- UPSERT. It was introduced out of concern that INSERT as a command tag would be a misrepresentation for ON CONFLICT DO UPDATE, as some affected rows may actually have been updated. Alvaro Herrera noticed that the implementation of that new command tag was incomplete; in subsequent discussion we concluded that having it doesn't provide benefits that are in line with the compatibility breaks it requires. Catversion bump due to the removal of PlannedStmt->isUpsert. Author: Peter Geoghegan Discussion: 20150520215816.GI5885@postgresql.org
* Refactor ON CONFLICT index inference parse tree representation.Andres Freund2015-05-19
| | | | | | | | | | | | | | Defer lookup of opfamily and input type of a of a user specified opclass until the optimizer selects among available unique indexes; and store the opclass in the parse analyzed tree instead. The primary reason for doing this is that for rule deparsing it's easier to use the opclass than the previous representation. While at it also rename a variable in the inference code to better fit it's purpose. This is separate from the actual fixes for deparsing to make review easier.
* Fix failure to copy IndexScan.indexorderbyops in copyfuncs.c.Tom Lane2015-05-17
| | | | | | | | | | | | | | | This oversight results in a crash at executor startup if the plan has been copied. outfuncs.c was missed as well. While we could probably have taught both those files to cope with the originally chosen representation of an Oid array, it would have been painful, not least because there'd be no easy way to verify the array length. An Oid List is far easier to work with. And AFAICS, there is no particular notational benefit to using an array rather than a list in the existing parts of the patch either. So just change it to a list. Error in commit 35fcb1b3d038a501f3f4c87c05630095abaaadab, which is new, so no need for back-patch.
* Support GROUPING SETS, CUBE and ROLLUP.Andres Freund2015-05-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This SQL standard functionality allows to aggregate data by different GROUP BY clauses at once. Each grouping set returns rows with columns grouped by in other sets set to NULL. This could previously be achieved by doing each grouping as a separate query, conjoined by UNION ALLs. Besides being considerably more concise, grouping sets will in many cases be faster, requiring only one scan over the underlying data. The current implementation of grouping sets only supports using sorting for input. Individual sets that share a sort order are computed in one pass. If there are sets that don't share a sort order, additional sort & aggregation steps are performed. These additional passes are sourced by the previous sort step; thus avoiding repeated scans of the source data. The code is structured in a way that adding support for purely using hash aggregation or a mix of hashing and sorting is possible. Sorting was chosen to be supported first, as it is the most generic method of implementation. Instead of, as in an earlier versions of the patch, representing the chain of sort and aggregation steps as full blown planner and executor nodes, all but the first sort are performed inside the aggregation node itself. This avoids the need to do some unusual gymnastics to handle having to return aggregated and non-aggregated tuples from underlying nodes, as well as having to shut down underlying nodes early to limit memory usage. The optimizer still builds Sort/Agg node to describe each phase, but they're not part of the plan tree, but instead additional data for the aggregation node. They're a convenient and preexisting way to describe aggregation and sorting. The first (and possibly only) sort step is still performed as a separate execution step. That retains similarity with existing group by plans, makes rescans fairly simple, avoids very deep plans (leading to slow explains) and easily allows to avoid the sorting step if the underlying data is sorted by other means. A somewhat ugly side of this patch is having to deal with a grammar ambiguity between the new CUBE keyword and the cube extension/functions named cube (and rollup). To avoid breaking existing deployments of the cube extension it has not been renamed, neither has cube been made a reserved keyword. Instead precedence hacking is used to make GROUP BY cube(..) refer to the CUBE grouping sets feature, and not the function cube(). To actually group by a function cube(), unlikely as that might be, the function name has to be quoted. Needs a catversion bump because stored rules may change. Author: Andrew Gierth and Atri Sharma, with contributions from Andres Freund Reviewed-By: Andres Freund, Noah Misch, Tom Lane, Svenne Krap, Tomas Vondra, Erik Rijkers, Marti Raudsepp, Pavel Stehule Discussion: CAOeZVidmVRe2jU6aMk_5qkxnB7dfmPROzM7Ur8JPW5j8Y5X-Lw@mail.gmail.com
* TABLESAMPLE, SQL Standard and extensibleSimon Riggs2015-05-15
| | | | | | | | | | | | | | Add a TABLESAMPLE clause to SELECT statements that allows user to specify random BERNOULLI sampling or block level SYSTEM sampling. Implementation allows for extensible sampling functions to be written, using a standard API. Basic version follows SQLStandard exactly. Usable concrete use cases for the sampling API follow in later commits. Petr Jelinek Reviewed by Michael Paquier and Simon Riggs
* Support VERBOSE option in REINDEX command.Fujii Masao2015-05-15
| | | | | | | | | | | | | | | | When this option is specified, a progress report is printed as each index is reindexed. Per discussion, we agreed on the following syntax for the extensibility of the options. REINDEX (flexible options) { INDEX | ... } name Sawada Masahiko. Reviewed by Robert Haas, Fabrízio Mello, Alvaro Herrera, Kyotaro Horiguchi, Jim Nasby and me. Discussion: CAD21AoA0pK3YcOZAFzMae+2fcc3oGp5zoRggDyMNg5zoaWDhdQ@mail.gmail.com
* Fix ON CONFLICT bugs that manifest when used in rules.Andres Freund2015-05-13
| | | | | | | | | | | | | | Specifically the tlist and rti of the pseudo "excluded" relation weren't properly treated by expression_tree_walker, which lead to errors when excluded was referenced inside a rule because the varnos where not properly adjusted. Similar omissions in OffsetVarNodes and expression_tree_mutator had less impact, but should obviously be fixed nonetheless. A couple tests of for ON CONFLICT UPDATE into INSERT rule bearing relations have been added. In passing I updated a couple comments.
* Allow on-the-fly capture of DDL event detailsAlvaro Herrera2015-05-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This feature lets user code inspect and take action on DDL events. Whenever a ddl_command_end event trigger is installed, DDL actions executed are saved to a list which can be inspected during execution of a function attached to ddl_command_end. The set-returning function pg_event_trigger_ddl_commands can be used to list actions so captured; it returns data about the type of command executed, as well as the affected object. This is sufficient for many uses of this feature. For the cases where it is not, we also provide a "command" column of a new pseudo-type pg_ddl_command, which is a pointer to a C structure that can be accessed by C code. The struct contains all the info necessary to completely inspect and even reconstruct the executed command. There is no actual deparse code here; that's expected to come later. What we have is enough infrastructure that the deparsing can be done in an external extension. The intention is that we will add some deparsing code in a later release, as an in-core extension. A new test module is included. It's probably insufficient as is, but it should be sufficient as a starting point for a more complete and future-proof approach. Authors: Álvaro Herrera, with some help from Andres Freund, Ian Barwick, Abhijit Menon-Sen. Reviews by Andres Freund, Robert Haas, Amit Kapila, Michael Paquier, Craig Ringer, David Steele. Additional input from Chris Browne, Dimitri Fontaine, Stephen Frost, Petr Jelínek, Tom Lane, Jim Nasby, Steven Singer, Pavel Stěhule. Based on original work by Dimitri Fontaine, though I didn't use his code. Discussion: https://www.postgresql.org/message-id/m2txrsdzxa.fsf@2ndQuadrant.fr https://www.postgresql.org/message-id/20131108153322.GU5809@eldon.alvh.no-ip.org https://www.postgresql.org/message-id/20150215044814.GL3391@alvh.no-ip.org
* Code review for foreign/custom join pushdown patch.Tom Lane2015-05-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit e7cb7ee14555cc9c5773e2c102efd6371f6f2005 included some design decisions that seem pretty questionable to me, and there was quite a lot of stuff not to like about the documentation and comments. Clean up as follows: * Consider foreign joins only between foreign tables on the same server, rather than between any two foreign tables with the same underlying FDW handler function. In most if not all cases, the FDW would simply have had to apply the same-server restriction itself (far more expensively, both for lack of caching and because it would be repeated for each combination of input sub-joins), or else risk nasty bugs. Anyone who's really intent on doing something outside this restriction can always use the set_join_pathlist_hook. * Rename fdw_ps_tlist/custom_ps_tlist to fdw_scan_tlist/custom_scan_tlist to better reflect what they're for, and allow these custom scan tlists to be used even for base relations. * Change make_foreignscan() API to include passing the fdw_scan_tlist value, since the FDW is required to set that. Backwards compatibility doesn't seem like an adequate reason to expect FDWs to set it in some ad-hoc extra step, and anyway existing FDWs can just pass NIL. * Change the API of path-generating subroutines of add_paths_to_joinrel, and in particular that of GetForeignJoinPaths and set_join_pathlist_hook, so that various less-used parameters are passed in a struct rather than as separate parameter-list entries. The objective here is to reduce the probability that future additions to those parameter lists will result in source-level API breaks for users of these hooks. It's possible that this is even a small win for the core code, since most CPU architectures can't pass more than half a dozen parameters efficiently anyway. I kept root, joinrel, outerrel, innerrel, and jointype as separate parameters to reduce code churn in joinpath.c --- in particular, putting jointype into the struct would have been problematic because of the subroutines' habit of changing their local copies of that variable. * Avoid ad-hocery in ExecAssignScanProjectionInfo. It was probably all right for it to know about IndexOnlyScan, but if the list is to grow we should refactor the knowledge out to the callers. * Restore nodeForeignscan.c's previous use of the relcache to avoid extra GetFdwRoutine lookups for base-relation scans. * Lots of cleanup of documentation and missed comments. Re-order some code additions into more logical places.
* Add support for INSERT ... ON CONFLICT DO NOTHING/UPDATE.Andres Freund2015-05-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The newly added ON CONFLICT clause allows to specify an alternative to raising a unique or exclusion constraint violation error when inserting. ON CONFLICT refers to constraints that can either be specified using a inference clause (by specifying the columns of a unique constraint) or by naming a unique or exclusion constraint. DO NOTHING avoids the constraint violation, without touching the pre-existing row. DO UPDATE SET ... [WHERE ...] updates the pre-existing tuple, and has access to both the tuple proposed for insertion and the existing tuple; the optional WHERE clause can be used to prevent an update from being executed. The UPDATE SET and WHERE clauses have access to the tuple proposed for insertion using the "magic" EXCLUDED alias, and to the pre-existing tuple using the table name or its alias. This feature is often referred to as upsert. This is implemented using a new infrastructure called "speculative insertion". It is an optimistic variant of regular insertion that first does a pre-check for existing tuples and then attempts an insert. If a violating tuple was inserted concurrently, the speculatively inserted tuple is deleted and a new attempt is made. If the pre-check finds a matching tuple the alternative DO NOTHING or DO UPDATE action is taken. If the insertion succeeds without detecting a conflict, the tuple is deemed inserted. To handle the possible ambiguity between the excluded alias and a table named excluded, and for convenience with long relation names, INSERT INTO now can alias its target table. Bumps catversion as stored rules change. Author: Peter Geoghegan, with significant contributions from Heikki Linnakangas and Andres Freund. Testing infrastructure by Jeff Janes. Reviewed-By: Heikki Linnakangas, Andres Freund, Robert Haas, Simon Riggs, Dean Rasheed, Stephen Frost and many others.
* Represent columns requiring insert and update privileges indentently.Andres Freund2015-05-08
| | | | | | | | | | | | | | | | | | | Previously, relation range table entries used a single Bitmapset field representing which columns required either UPDATE or INSERT privileges, despite the fact that INSERT and UPDATE privileges are separately cataloged, and may be independently held. As statements so far required either insert or update privileges but never both, that was sufficient. The required permission could be inferred from the top level statement run. The upcoming INSERT ... ON CONFLICT UPDATE feature needs to independently check for both privileges in one statement though, so that is not sufficient anymore. Bumps catversion as stored rules change. Author: Peter Geoghegan Reviewed-By: Andres Freund
* Allow FDWs and custom scan providers to replace joins with scans.Robert Haas2015-05-01
| | | | | | | | | | | | | | | | | Foreign data wrappers can use this capability for so-called "join pushdown"; that is, instead of executing two separate foreign scans and then joining the results locally, they can generate a path which performs the join on the remote server and then is scanned locally. This commit does not extend postgres_fdw to take advantage of this capability; it just provides the infrastructure. Custom scan providers can use this in a similar way. Previously, it was only possible for a custom scan provider to scan a single relation. Now, it can scan an entire join tree, provided of course that it knows how to produce the same results that the join would have produced if executed normally. KaiGai Kohei, reviewed by Shigeru Hanada, Ashutosh Bapat, and me.
* Add transforms featurePeter Eisentraut2015-04-26
| | | | | | | | This provides a mechanism for specifying conversions between SQL data types and procedural languages. As examples, there are transforms for hstore and ltree for PL/Perl and PL/Python. reviews by Pavel Stěhule and Andres Freund
* Perform RLS WITH CHECK before constraints, etcStephen Frost2015-04-24
| | | | | | | | | | | | | | | | | | | | | | | The RLS capability is built on top of the WITH CHECK OPTION system which was added for auto-updatable views, however, unlike WCOs on views (which are mandated by the SQL spec to not fire until after all other constraints and checks are done), it makes much more sense for RLS checks to happen earlier than constraint and uniqueness checks. This patch reworks the structure which holds the WCOs a bit to be explicitly either VIEW or RLS checks and the RLS-related checks are done prior to the constraint and uniqueness checks. This also allows better error reporting as we are now reporting when a violation is due to a WITH CHECK OPTION and when it's due to an RLS policy violation, which was independently noted by Craig Ringer as being confusing. The documentation is also updated to include a paragraph about when RLS WITH CHECK handling is performed, as there have been a number of questions regarding that and the documentation was previously silent on the matter. Author: Dean Rasheed, with some kabitzing and comment changes by me.
* Rationalize vacuuming options and parametersAlvaro Herrera2015-03-18
| | | | | | | | | | | | | | | | | | | We were involving the parser too much in setting up initial vacuuming parameters. This patch moves that responsibility elsewhere to simplify code, and also to make future additions easier. To do this, create a new struct VacuumParams which is filled just prior to vacuum execution, instead of at parse time; for user-invoked vacuuming this is set up in a new function ExecVacuum, while autovacuum sets it up by itself. While at it, add a new member VACOPT_SKIPTOAST to enum VacuumOption, only set by autovacuum, which is used to disable vacuuming of the toast table instead of the old do_toast parameter; this relieves the argument list of vacuum() and some callees a bit. This partially makes up for having added more arguments in an effort to avoid having autovacuum from constructing a VacuumStmt parse node. Author: Michael Paquier. Some tweaks by Álvaro Reviewed by: Robert Haas, Stephen Frost, Álvaro Herrera