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* Fix bitmap AND/OR scans on the inside of a nestloop partition-wise join.Tom Lane2020-07-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | reparameterize_path_by_child() failed to reparameterize BitmapAnd and BitmapOr paths. This matters only if such a path is chosen as the inside of a nestloop partition-wise join, where we have to pass in parameters from the outside of the nestloop. If that did happen, we generated a bad plan that would likely lead to crashes at execution. This is not entirely reparameterize_path_by_child()'s fault though; it's the victim of an ancient decision (my ancient decision, I think) to not bother filling in param_info in BitmapAnd/Or path nodes. That caused the function to believe that such nodes and their children contain no parameter references and so need not be processed. In hindsight that decision looks pretty penny-wise and pound-foolish: while it saves a few cycles during path node setup, we do commonly need the information later. In particular, by reversing the decision and requiring valid param_info data in all nodes of a bitmap path tree, we can get rid of indxpath.c's get_bitmap_tree_required_outer() function, which computed the data on-demand. It's not unlikely that that nets out as a savings of cycles in many scenarios. A couple of other things in indxpath.c can be simplified as well. While here, get rid of some cases in reparameterize_path_by_child() that are visibly dead or useless, given that we only care about reparameterizing paths that can be on the inside of a parameterized nestloop. This case reminds one of the maxim that untested code probably does not work, so I'm unwilling to leave unreachable code in this function. (I did leave the T_Gather case in place even though it's not reached in the regression tests. It's not very clear to me when the planner might prefer to put Gather below rather than above a nestloop, but at least in principle the case might be interesting.) Per bug #16536, originally from Arne Roland but with a test case by Andrew Gierth. Back-patch to v11 where this code came in. Discussion: https://postgr.es/m/16536-2213ee0b3aad41fd@postgresql.org
* Update copyrights for 2020Bruce Momjian2020-01-01
| | | | Backpatch-through: update all files in master, backpatch legal files through 9.4
* Rationalize use of list_concat + list_copy combinations.Tom Lane2019-08-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | In the wake of commit 1cff1b95a, the result of list_concat no longer shares the ListCells of the second input. Therefore, we can replace "list_concat(x, list_copy(y))" with just "list_concat(x, y)". To improve call sites that were list_copy'ing the first argument, or both arguments, invent "list_concat_copy()" which produces a new list sharing no ListCells with either input. (This is a bit faster than "list_concat(list_copy(x), y)" because it makes the result list the right size to start with.) In call sites that were not list_copy'ing the second argument, the new semantics mean that we are usually leaking the second List's storage, since typically there is no remaining pointer to it. We considered inventing another list_copy variant that would list_free the second input, but concluded that for most call sites it isn't worth worrying about, given the relative compactness of the new List representation. (Note that in cases where such leakage would happen, the old code already leaked the second List's header; so we're only discussing the size of the leak not whether there is one. I did adjust two or three places that had been troubling to free that header so that they manually free the whole second List.) Patch by me; thanks to David Rowley for review. Discussion: https://postgr.es/m/11587.1550975080@sss.pgh.pa.us
* Represent Lists as expansible arrays, not chains of cons-cells.Tom Lane2019-07-15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Originally, Postgres Lists were a more or less exact reimplementation of Lisp lists, which consist of chains of separately-allocated cons cells, each having a value and a next-cell link. We'd hacked that once before (commit d0b4399d8) to add a separate List header, but the data was still in cons cells. That makes some operations -- notably list_nth() -- O(N), and it's bulky because of the next-cell pointers and per-cell palloc overhead, and it's very cache-unfriendly if the cons cells end up scattered around rather than being adjacent. In this rewrite, we still have List headers, but the data is in a resizable array of values, with no next-cell links. Now we need at most two palloc's per List, and often only one, since we can allocate some values in the same palloc call as the List header. (Of course, extending an existing List may require repalloc's to enlarge the array. But this involves just O(log N) allocations not O(N).) Of course this is not without downsides. The key difficulty is that addition or deletion of a list entry may now cause other entries to move, which it did not before. For example, that breaks foreach() and sister macros, which historically used a pointer to the current cons-cell as loop state. We can repair those macros transparently by making their actual loop state be an integer list index; the exposed "ListCell *" pointer is no longer state carried across loop iterations, but is just a derived value. (In practice, modern compilers can optimize things back to having just one loop state value, at least for simple cases with inline loop bodies.) In principle, this is a semantics change for cases where the loop body inserts or deletes list entries ahead of the current loop index; but I found no such cases in the Postgres code. The change is not at all transparent for code that doesn't use foreach() but chases lists "by hand" using lnext(). The largest share of such code in the backend is in loops that were maintaining "prev" and "next" variables in addition to the current-cell pointer, in order to delete list cells efficiently using list_delete_cell(). However, we no longer need a previous-cell pointer to delete a list cell efficiently. Keeping a next-cell pointer doesn't work, as explained above, but we can improve matters by changing such code to use a regular foreach() loop and then using the new macro foreach_delete_current() to delete the current cell. (This macro knows how to update the associated foreach loop's state so that no cells will be missed in the traversal.) There remains a nontrivial risk of code assuming that a ListCell * pointer will remain good over an operation that could now move the list contents. To help catch such errors, list.c can be compiled with a new define symbol DEBUG_LIST_MEMORY_USAGE that forcibly moves list contents whenever that could possibly happen. This makes list operations significantly more expensive so it's not normally turned on (though it is on by default if USE_VALGRIND is on). There are two notable API differences from the previous code: * lnext() now requires the List's header pointer in addition to the current cell's address. * list_delete_cell() no longer requires a previous-cell argument. These changes are somewhat unfortunate, but on the other hand code using either function needs inspection to see if it is assuming anything it shouldn't, so it's not all bad. Programmers should be aware of these significant performance changes: * list_nth() and related functions are now O(1); so there's no major access-speed difference between a list and an array. * Inserting or deleting a list element now takes time proportional to the distance to the end of the list, due to moving the array elements. (However, it typically *doesn't* require palloc or pfree, so except in long lists it's probably still faster than before.) Notably, lcons() used to be about the same cost as lappend(), but that's no longer true if the list is long. Code that uses lcons() and list_delete_first() to maintain a stack might usefully be rewritten to push and pop at the end of the list rather than the beginning. * There are now list_insert_nth...() and list_delete_nth...() functions that add or remove a list cell identified by index. These have the data-movement penalty explained above, but there's no search penalty. * list_concat() and variants now copy the second list's data into storage belonging to the first list, so there is no longer any sharing of cells between the input lists. The second argument is now declared "const List *" to reflect that it isn't changed. This patch just does the minimum needed to get the new implementation in place and fix bugs exposed by the regression tests. As suggested by the foregoing, there's a fair amount of followup work remaining to do. Also, the ENABLE_LIST_COMPAT macros are finally removed in this commit. Code using those should have been gone a dozen years ago. Patch by me; thanks to David Rowley, Jesper Pedersen, and others for review. Discussion: https://postgr.es/m/11587.1550975080@sss.pgh.pa.us
* Phase 2 pgindent run for v12.Tom Lane2019-05-22
| | | | | | | | | Switch to 2.1 version of pg_bsd_indent. This formats multiline function declarations "correctly", that is with additional lines of parameter declarations indented to match where the first line's left parenthesis is. Discussion: https://postgr.es/m/CAEepm=0P3FeTXRcU5B2W3jv3PgRVZ-kGUXLGfd42FFhUROO3ug@mail.gmail.com
* Simplify the planner's new representation of indexable clauses a little.Tom Lane2019-02-14
| | | | | | | | | | | | | | | | | | | | | | In commit 1a8d5afb0, I thought it'd be a good idea to define IndexClause.indexquals as NIL in the most common case where the given clause (IndexClause.rinfo) is usable exactly as-is. It'd be more consistent to define the indexquals in that case as being a one-element list containing IndexClause.rinfo, but I thought saving the palloc overhead for making such a list would be worthwhile. In hindsight, that was a great example of "premature optimization is the root of all evil": it's complicated everyplace that needs to deal with the indexquals, requiring duplicative code to handle both the simple case and the not-simple case. I'd initially found that tolerable but it's getting less so as I mop up some areas that I'd not touched in 1a8d5afb0. In any case, two more pallocs during a planner run are surely at the noise level (a conclusion confirmed by a bit of microbenchmarking). So let's change this decision before it becomes set in stone, and insist that IndexClause.indexquals always be a valid list of the actual index quals for the clause. Discussion: https://postgr.es/m/24586.1550106354@sss.pgh.pa.us
* Clean up planner confusion between ncolumns and nkeycolumns.Tom Lane2019-02-12
| | | | | | | | | | | | | | | | | | | | | | | | | We're only going to consider key columns when creating indexquals, so there is no point in having the outer loops in indxpath.c iterate further than nkeycolumns. Doing so in match_pathkeys_to_index() is actually wrong, and would have caused crashes by now, except that we have no index AMs supporting both amcanorderbyop and amcaninclude. It's also wrong in relation_has_unique_index_for(). The effect there is to fail to prove uniqueness even when the index does prove it, if there are extra columns. Also future-proof examine_variable() for the day when extra columns can be expressions, and fix what's either a thinko or just an oversight in btcostestimate(): we should consider the number of key columns, not the total, when deciding whether to derate correlation. None of these things seemed important enough to risk changing in a just-before-wrap patch, but since we're past the release wrap window, time to fix 'em. Discussion: https://postgr.es/m/25526.1549847928@sss.pgh.pa.us
* Allow extensions to generate lossy index conditions.Tom Lane2019-02-11
| | | | | | | | | | | | | | | | | | | | | | | | For a long time, indxpath.c has had the ability to extract derived (lossy) index conditions from certain operators such as LIKE. For just as long, it's been obvious that we really ought to make that capability available to extensions. This commit finally accomplishes that, by adding another API for planner support functions that lets them create derived index conditions for their functions. As proof of concept, the hardwired "special index operator" code formerly present in indxpath.c is pushed out to planner support functions attached to LIKE and other relevant operators. A weak spot in this design is that an extension needs to know OIDs for the operators, datatypes, and opfamilies involved in the transformation it wants to make. The core-code prototypes use hard-wired OID references but extensions don't have that option for their own operators etc. It's usually possible to look up the required info, but that may be slow and inconvenient. However, improving that situation is a separate task. I want to do some additional refactorization around selfuncs.c, but that also seems like a separate task. Discussion: https://postgr.es/m/15193.1548028093@sss.pgh.pa.us
* Fix indexable-row-comparison logic to account for covering indexes.Tom Lane2019-02-10
| | | | | | | | | | | | | | | | | | indxpath.c needs a good deal more attention for covering indexes than it's gotten. But so far as I can tell, the only really awful breakage is in expand_indexqual_rowcompare (nee adjust_rowcompare_for_index), which was only half fixed in c266ed31a. The other problems aren't bad enough to take the risk of a just-before-wrap fix. The problem here is that if the leading column of a row comparison matches an index (allowing this code to be reached), and some later column doesn't match the index, it'll nonetheless believe that that column matches the first included index column. Typically that'll lead to an error like "operator M is not a member of opfamily N" as a result of fetching a garbage opfamily OID. But with enough bad luck, maybe a broken plan would be generated. Discussion: https://postgr.es/m/25526.1549847928@sss.pgh.pa.us
* Refactor the representation of indexable clauses in IndexPaths.Tom Lane2019-02-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In place of three separate but interrelated lists (indexclauses, indexquals, and indexqualcols), an IndexPath now has one list "indexclauses" of IndexClause nodes. This holds basically the same information as before, but in a more useful format: in particular, there is now a clear connection between an indexclause (an original restriction clause from WHERE or JOIN/ON) and the indexquals (directly usable index conditions) derived from it. We also change the ground rules a bit by mandating that clause commutation, if needed, be done up-front so that what is stored in the indexquals list is always directly usable as an index condition. This gets rid of repeated re-determination of which side of the clause is the indexkey during costing and plan generation, as well as repeated lookups of the commutator operator. To minimize the added up-front cost, the typical case of commuting a plain OpExpr is handled by a new special-purpose function commute_restrictinfo(). For RowCompareExprs, generating the new clause properly commuted to begin with is not really any more complex than before, it's just different --- and we can save doing that work twice, as the pretty-klugy original implementation did. Tracking the connection between original and derived clauses lets us also track explicitly whether the derived clauses are an exact or lossy translation of the original. This provides a cheap solution to getting rid of unnecessary rechecks of boolean index clauses, which previously seemed like it'd be more expensive than it was worth. Another pleasant (IMO) side-effect is that EXPLAIN now always shows index clauses with the indexkey on the left; this seems less confusing. This commit leaves expand_indexqual_conditions() and some related functions in a slightly messy state. I didn't bother to change them any more than minimally necessary to work with the new data structure, because all that code is going to be refactored out of existence in a follow-on patch. Discussion: https://postgr.es/m/22182.1549124950@sss.pgh.pa.us
* Refactor planner's header files.Tom Lane2019-01-29
| | | | | | | | | | | | | | | | | | | | | | | | Create a new header optimizer/optimizer.h, which exposes just the planner functions that can be used "at arm's length", without need to access Paths or the other planner-internal data structures defined in nodes/relation.h. This is intended to provide the whole planner API seen by most of the rest of the system; although FDWs still need to use additional stuff, and more thought is also needed about just what selfuncs.c should rely on. The main point of doing this now is to limit the amount of new #include baggage that will be needed by "planner support functions", which I expect to introduce later, and which will be in relevant datatype modules rather than anywhere near the planner. This commit just moves relevant declarations into optimizer.h from other header files (a couple of which go away because everything got moved), and adjusts #include lists to match. There's further cleanup that could be done if we want to decide that some stuff being exposed by optimizer.h doesn't belong in the planner at all, but I'll leave that for another day. Discussion: https://postgr.es/m/11460.1548706639@sss.pgh.pa.us
* Make some small planner API cleanups.Tom Lane2019-01-29
| | | | | | | | | | | | | | | | | | | | | | Move a few very simple node-creation and node-type-testing functions from the planner's clauses.c to nodes/makefuncs and nodes/nodeFuncs. There's nothing planner-specific about them, as evidenced by the number of other places that were using them. While at it, rename and_clause() etc to is_andclause() etc, to clarify that they are node-type-testing functions not node-creation functions. And use "static inline" implementations for the shortest ones. Also, modify flatten_join_alias_vars() and some subsidiary functions to take a Query not a PlannerInfo to define the join structure that Vars should be translated according to. They were only using the "parse" field of the PlannerInfo anyway, so this just requires removing one level of indirection. The advantage is that now parse_agg.c can use flatten_join_alias_vars() without the horrid kluge of creating an incomplete PlannerInfo, which will allow that file to be decoupled from relation.h in a subsequent patch. Discussion: https://postgr.es/m/11460.1548706639@sss.pgh.pa.us
* Update copyright for 2019Bruce Momjian2019-01-02
| | | | Backpatch-through: certain files through 9.4
* Add text-vs-name cross-type operators, and unify name_ops with text_ops.Tom Lane2018-12-19
| | | | | | | | | | | | | | | | | | | Now that name comparison has effectively the same behavior as text comparison, we might as well merge the name_ops opfamily into text_ops, allowing cross-type comparisons to be processed without forcing a datatype coercion first. We need do little more than add cross-type operators to make the opfamily complete, and fix one or two places in the planner that assumed text_ops was a single-datatype opfamily. I chose to unify hash name_ops into hash text_ops as well, since the types have compatible hashing semantics. This allows marking the new cross-type equality operators as oprcanhash. (Note: this doesn't remove the name_ops opclasses, so there's no breakage of index definitions. Those opclasses are just reparented into the text_ops opfamily.) Discussion: https://postgr.es/m/15938.1544377821@sss.pgh.pa.us
* Make type "name" collation-aware.Tom Lane2018-12-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | The "name" comparison operators now all support collations, making them functionally equivalent to "text" comparisons, except for the different physical representation of the datatype. They do, in fact, mostly share the varstr_cmp and varstr_sortsupport infrastructure, which has been slightly enlarged to handle the case. To avoid changes in the default behavior of the datatype, set name's typcollation to C_COLLATION_OID not DEFAULT_COLLATION_OID, so that by default comparisons to a name value will continue to use strcmp semantics. (This would have been the case for system catalog columns anyway, because of commit 6b0faf723, but doing this makes it true for user-created name columns as well. In particular, this avoids locale-dependent changes in our regression test results.) In consequence, tweak a couple of places that made assumptions about collatable base types always having typcollation DEFAULT_COLLATION_OID. I have not, however, attempted to relax the restriction that user- defined collatable types must have that. Hence, "name" doesn't behave quite like a user-defined type; it acts more like a domain with COLLATE "C". (Conceivably, if we ever get rid of the need for catalog name columns to be fixed-length, "name" could actually become such a domain over text. But that'd be a pretty massive undertaking, and I'm not volunteering.) Discussion: https://postgr.es/m/15938.1544377821@sss.pgh.pa.us
* Limit the number of index clauses considered in choose_bitmap_and().Tom Lane2018-11-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | classify_index_clause_usage() is O(N^2) in the number of distinct index qual clauses it considers, because of its use of a simple search list to store them. For nearly all queries, that's fine because only a few clauses will be considered. But Alexander Kuzmenkov reported a machine-generated query with 80000 (!) index qual clauses, which caused this code to take forever. Somewhat remarkably, this is the only O(N^2) behavior we now have for such a query, so let's fix it. We can get rid of the O(N^2) runtime for cases like this without much damage to the functionality of choose_bitmap_and() by separating out paths with "too many" qual or pred clauses, and deeming them to always be nonredundant with other paths. Then their clauses needn't go into the search list, so it doesn't get too long, but we don't lose the ability to consider bitmap AND plans altogether. I set the threshold for "too many" to be 100 clauses per path, which should be plenty to ensure no change in planning behavior for normal queries. There are other things we could do to make this go faster, but it's not clear that it's worth any additional effort. 80000 qual clauses require a whole lot of work in many other places, too. The code's been like this for a long time, so back-patch to all supported branches. The troublesome query only works back to 9.5 (in 9.4 it fails with stack overflow in the parser); so I'm not sure that fixing this in 9.4 has any real-world benefit, but perhaps it does. Discussion: https://postgr.es/m/90c5bdfa-d633-dabe-9889-3cf3e1acd443@postgrespro.ru
* Post-feature-freeze pgindent run.Tom Lane2018-04-26
| | | | Discussion: https://postgr.es/m/15719.1523984266@sss.pgh.pa.us
* Cleanup covering infrastructureTeodor Sigaev2018-04-12
| | | | | | | | | | | - Explicitly forbids opclass, collation and indoptions (like DESC/ASC etc) for including columns. Throw an error if user points that. - Truncated storage arrays for such attributes to store only key atrributes, added assertion checks. - Do not check opfamily and collation for including columns in CompareIndexInfo() Discussion: https://www.postgresql.org/message-id/5ee72852-3c4e-ee35-e2ed-c1d053d45c08@sigaev.ru
* match_clause_to_index should check only key columnsTeodor Sigaev2018-04-08
| | | | | Alexander Korotkov per gripe from Tom Lane noticed on valgrind-enabled buildfarm members
* Indexes with INCLUDE columns and their support in B-treeTeodor Sigaev2018-04-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch introduces INCLUDE clause to index definition. This clause specifies a list of columns which will be included as a non-key part in the index. The INCLUDE columns exist solely to allow more queries to benefit from index-only scans. Also, such columns don't need to have appropriate operator classes. Expressions are not supported as INCLUDE columns since they cannot be used in index-only scans. Index access methods supporting INCLUDE are indicated by amcaninclude flag in IndexAmRoutine. For now, only B-tree indexes support INCLUDE clause. In B-tree indexes INCLUDE columns are truncated from pivot index tuples (tuples located in non-leaf pages and high keys). Therefore, B-tree indexes now might have variable number of attributes. This patch also provides generic facility to support that: pivot tuples contain number of their attributes in t_tid.ip_posid. Free 13th bit of t_info is used for indicating that. This facility will simplify further support of index suffix truncation. The changes of above are backward-compatible, pg_upgrade doesn't need special handling of B-tree indexes for that. Bump catalog version Author: Anastasia Lubennikova with contribition by Alexander Korotkov and me Reviewed by: Peter Geoghegan, Tomas Vondra, Antonin Houska, Jeff Janes, David Rowley, Alexander Korotkov Discussion: https://www.postgresql.org/message-id/flat/56168952.4010101@postgrespro.ru
* Faster partition pruningAlvaro Herrera2018-04-06
| | | | | | | | | | | | | | | | | | | | | Add a new module backend/partitioning/partprune.c, implementing a more sophisticated algorithm for partition pruning. The new module uses each partition's "boundinfo" for pruning instead of constraint exclusion, based on an idea proposed by Robert Haas of a "pruning program": a list of steps generated from the query quals which are run iteratively to obtain a list of partitions that must be scanned in order to satisfy those quals. At present, this targets planner-time partition pruning, but there exist further patches to apply partition pruning at execution time as well. This commit also moves some definitions from include/catalog/partition.h to a new file include/partitioning/partbounds.h, in an attempt to rationalize partitioning related code. Authors: Amit Langote, David Rowley, Dilip Kumar Reviewers: Robert Haas, Kyotaro Horiguchi, Ashutosh Bapat, Jesper Pedersen. Discussion: https://postgr.es/m/098b9c71-1915-1a2a-8d52-1a7a50ce79e8@lab.ntt.co.jp
* Fix IOS planning when only some index columns can return an attribute.Tom Lane2018-03-01
| | | | | | | | | | | | | | | | | | | | | | | Since 9.5, it's possible that some but not all columns of an index support returning the indexed value for index-only scans. If the same indexed column appears in index columns that behave both ways, check_index_only() supposed that it'd be OK to do an index-only scan testing that column; but that fails if we have to recheck the indexed condition on one of the columns that doesn't support this. In principle we could make this work by remapping the recheck expressions to pull the value from a column that does support returning the indexed value. But such cases are so weird and rare that, at least for now, it doesn't seem worth the trouble. Instead, just teach check_index_only that a value is returnable only if all the index columns containing it are returnable, rather than any of them. Per report from David Pereiro Lagares. Back-patch to 9.5 where the possibility of this situation appeared. Kyotaro Horiguchi Discussion: https://postgr.es/m/1516210494.1798.16.camel@nlpgo.com
* Update copyright for 2018Bruce Momjian2018-01-02
| | | | Backpatch-through: certain files through 9.3
* Change TRUE/FALSE to true/falsePeter Eisentraut2017-11-08
| | | | | | | | | | | | | | The lower case spellings are C and C++ standard and are used in most parts of the PostgreSQL sources. The upper case spellings are only used in some files/modules. So standardize on the standard spellings. The APIs for ICU, Perl, and Windows define their own TRUE and FALSE, so those are left as is when using those APIs. In code comments, we use the lower-case spelling for the C concepts and keep the upper-case spelling for the SQL concepts. Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
* Be more consistent about errors for opfamily member lookup failures.Tom Lane2017-07-24
| | | | | | | | | | | | | | | Add error checks in some places that were calling get_opfamily_member or get_opfamily_proc and just assuming that the call could never fail. Also, standardize the wording for such errors in some other places. None of these errors are expected in normal use, hence they're just elog not ereport. But they may be handy for diagnosing omissions in custom opclasses. Rushabh Lathia found the oversight in RelationBuildPartitionKey(); I found the others by grepping for all callers of these functions. Discussion: https://postgr.es/m/CAGPqQf2R9Nk8htpv0FFi+FP776EwMyGuORpc9zYkZKC8sFQE3g@mail.gmail.com
* Phase 3 of pgindent updates.Tom Lane2017-06-21
| | | | | | | | | | | | | | | | | | | | | | | | | Don't move parenthesized lines to the left, even if that means they flow past the right margin. By default, BSD indent lines up statement continuation lines that are within parentheses so that they start just to the right of the preceding left parenthesis. However, traditionally, if that resulted in the continuation line extending to the right of the desired right margin, then indent would push it left just far enough to not overrun the margin, if it could do so without making the continuation line start to the left of the current statement indent. That makes for a weird mix of indentations unless one has been completely rigid about never violating the 80-column limit. This behavior has been pretty universally panned by Postgres developers. Hence, disable it with indent's new -lpl switch, so that parenthesized lines are always lined up with the preceding left paren. This patch is much less interesting than the first round of indent changes, but also bulkier, so I thought it best to separate the effects. Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
* Phase 2 of pgindent updates.Tom Lane2017-06-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Change pg_bsd_indent to follow upstream rules for placement of comments to the right of code, and remove pgindent hack that caused comments following #endif to not obey the general rule. Commit e3860ffa4dd0dad0dd9eea4be9cc1412373a8c89 wasn't actually using the published version of pg_bsd_indent, but a hacked-up version that tried to minimize the amount of movement of comments to the right of code. The situation of interest is where such a comment has to be moved to the right of its default placement at column 33 because there's code there. BSD indent has always moved right in units of tab stops in such cases --- but in the previous incarnation, indent was working in 8-space tab stops, while now it knows we use 4-space tabs. So the net result is that in about half the cases, such comments are placed one tab stop left of before. This is better all around: it leaves more room on the line for comment text, and it means that in such cases the comment uniformly starts at the next 4-space tab stop after the code, rather than sometimes one and sometimes two tabs after. Also, ensure that comments following #endif are indented the same as comments following other preprocessor commands such as #else. That inconsistency turns out to have been self-inflicted damage from a poorly-thought-through post-indent "fixup" in pgindent. This patch is much less interesting than the first round of indent changes, but also bulkier, so I thought it best to separate the effects. Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
* Teach predtest.c about CHECK clauses to fix partitioning bugs.Robert Haas2017-06-14
| | | | | | | | | | | | | | | | | | In a CHECK clause, a null result means true, whereas in a WHERE clause it means false. predtest.c provided different functions depending on which set of semantics applied to the predicate being proved, but had no option to control what a null meant in the clauses provided as axioms. Add one. Use that in the partitioning code when figuring out whether the validation scan on a new partition can be skipped. Rip out the old logic that attempted (not very successfully) to compensate for the absence of the necessary support in predtest.c. Ashutosh Bapat and Robert Haas, reviewed by Amit Langote and incorporating feedback from Tom Lane. Discussion: http://postgr.es/m/CAFjFpReT_kq_uwU_B8aWDxR7jNGE=P0iELycdq5oupi=xSQTOw@mail.gmail.com
* Post-PG 10 beta1 pgindent runBruce Momjian2017-05-17
| | | | perltidy run not included.
* Improve castNode notation by introducing list-extraction-specific variants.Tom Lane2017-04-10
| | | | | | | | | | | | | | | | | This extends the castNode() notation introduced by commit 5bcab1114 to provide, in one step, extraction of a list cell's pointer and coercion to a concrete node type. For example, "lfirst_node(Foo, lc)" is the same as "castNode(Foo, lfirst(lc))". Almost half of the uses of castNode that have appeared so far include a list extraction call, so this is pretty widely useful, and it saves a few more keystrokes compared to the old way. As with the previous patch, back-patch the addition of these macros to pg_list.h, so that the notation will be available when back-patching. Patch by me, after an idea of Andrew Gierth's. Discussion: https://postgr.es/m/14197.1491841216@sss.pgh.pa.us
* Abstract logic to allow for multiple kinds of child rels.Robert Haas2017-04-03
| | | | | | | | | | | | | | | | | | | | | | Currently, the only type of child relation is an "other member rel", which is the child of a baserel, but in the future joins and even upper relations may have child rels. To facilitate that, introduce macros that test to test for particular RelOptKind values, and use them in various places where they help to clarify the sense of a test. (For example, a test may allow RELOPT_OTHER_MEMBER_REL either because it intends to allow child rels, or because it intends to allow simple rels.) Also, remove find_childrel_top_parent, which will not work for a child rel that is not a baserel. Instead, add a new RelOptInfo member top_parent_relids to track the same kind of information in a more generic manner. Ashutosh Bapat, slightly tweaked by me. Review and testing of the patch set from which this was taken by Rajkumar Raghuwanshi and Rafia Sabih. Discussion: http://postgr.es/m/CA+TgmoagTnF2yqR3PT2rv=om=wJiZ4-A+ATwdnriTGku1CLYxA@mail.gmail.com
* Cast result of copyObject() to correct typePeter Eisentraut2017-03-28
| | | | | | | | | | | | | | copyObject() is declared to return void *, which allows easily assigning the result independent of the input, but it loses all type checking. If the compiler supports typeof or something similar, cast the result to the input type. This creates a greater amount of type safety. In some cases, where the result is assigned to a generic type such as Node * or Expr *, new casts are now necessary, but in general casts are now unnecessary in the normal case and indicate that something unusual is happening. Reviewed-by: Mark Dilger <hornschnorter@gmail.com>
* Support parallel bitmap heap scans.Robert Haas2017-03-08
| | | | | | | | | | | | | | | The index is scanned by a single process, but then all cooperating processes can iterate jointly over the resulting set of heap blocks. In the future, we might also want to support using a parallel bitmap index scan to set up for a parallel bitmap heap scan, but that's a job for another day. Dilip Kumar, with some corrections and cosmetic changes by me. The larger patch set of which this is a part has been reviewed and tested by (at least) Andres Freund, Amit Khandekar, Tushar Ahuja, Rafia Sabih, Haribabu Kommi, Thomas Munro, and me. Discussion: http://postgr.es/m/CAFiTN-uc4=0WxRGfCzs-xfkMYcSEWUC-Fon6thkJGjkh9i=13A@mail.gmail.com
* Suppress unused-variable warning.Tom Lane2017-02-21
| | | | | | Rearrange so we don't have an unused variable in disable-cassert case. Discussion: https://postgr.es/m/CAMkU=1x63f2QyFTeas83xJqD+Hm1PBuok1LrzYzS-OngDzYOVA@mail.gmail.com
* Make more use of castNode()Peter Eisentraut2017-02-21
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* Add optimizer and executor support for parallel index-only scans.Robert Haas2017-02-19
| | | | | | | | | | | | | Commit 5262f7a4fc44f651241d2ff1fa688dd664a34874 added similar support for parallel index scans; this extends that work to index-only scans. As with parallel index scans, this requires support from the index AM, so currently parallel index-only scans will only be possible for btree indexes. Rafia Sabih, reviewed and tested by Rahila Syed, Tushar Ahuja, and Amit Kapila Discussion: http://postgr.es/m/CAOGQiiPEAs4C=TBp0XShxBvnWXuzGL2u++Hm1=qnCpd6_Mf8Fw@mail.gmail.com
* Add optimizer and executor support for parallel index scans.Robert Haas2017-02-15
| | | | | | | | | | | | In combination with 569174f1be92be93f5366212cc46960d28a5c5cd, which taught the btree AM how to perform parallel index scans, this allows parallel index scan plans on btree indexes. This infrastructure should be general enough to support parallel index scans for other index AMs as well, if someone updates them to support parallel scans. Amit Kapila, reviewed and tested by Anastasia Lubennikova, Tushar Ahuja, and Haribabu Kommi, and me.
* Improve RLS planning by marking individual quals with security levels.Tom Lane2017-01-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In an RLS query, we must ensure that security filter quals are evaluated before ordinary query quals, in case the latter contain "leaky" functions that could expose the contents of sensitive rows. The original implementation of RLS planning ensured this by pushing the scan of a secured table into a sub-query that it marked as a security-barrier view. Unfortunately this results in very inefficient plans in many cases, because the sub-query cannot be flattened and gets planned independently of the rest of the query. To fix, drop the use of sub-queries to enforce RLS qual order, and instead mark each qual (RestrictInfo) with a security_level field establishing its priority for evaluation. Quals must be evaluated in security_level order, except that "leakproof" quals can be allowed to go ahead of quals of lower security_level, if it's helpful to do so. This has to be enforced within the ordering of any one list of quals to be evaluated at a table scan node, and we also have to ensure that quals are not chosen for early evaluation (i.e., use as an index qual or TID scan qual) if they're not allowed to go ahead of other quals at the scan node. This is sufficient to fix the problem for RLS quals, since we only support RLS policies on simple tables and thus RLS quals will always exist at the table scan level only. Eventually these qual ordering rules should be enforced for join quals as well, which would permit improving planning for explicit security-barrier views; but that's a task for another patch. Note that FDWs would need to be aware of these rules --- and not, for example, send an insecure qual for remote execution --- but since we do not yet allow RLS policies on foreign tables, the case doesn't arise. This will need to be addressed before we can allow such policies. Patch by me, reviewed by Stephen Frost and Dean Rasheed. Discussion: https://postgr.es/m/8185.1477432701@sss.pgh.pa.us
* Fix matching of boolean index columns to sort ordering.Tom Lane2017-01-15
| | | | | | | | | | | | | | | | | | Normally, if we have a WHERE clause like "indexcol = constant", the planner will figure out that that index column can be ignored when determining whether the index has a desired sort ordering. But this failed to work for boolean index columns, because a condition like "boolcol = true" is canonicalized to just "boolcol" which does not give rise to an EquivalenceClass. Add a check to allow the same type of deduction to be made in this case too. Per a complaint from Dima Pavlov. Arguably this is a bug, but given the limited impact and the small number of complaints so far, I won't risk destabilizing plans in stable branches by back-patching. Patch by me, reviewed by Michael Paquier Discussion: https://postgr.es/m/1788.1481605684@sss.pgh.pa.us
* Update copyright via script for 2017Bruce Momjian2017-01-03
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* 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
* Support using index-only scans with partial indexes in more cases.Tom Lane2016-03-31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Previously, the planner would reject an index-only scan if any restriction clause for its table used a column not available from the index, even if that restriction clause would later be dropped from the plan entirely because it's implied by the index's predicate. This is a fairly common situation for partial indexes because predicates using columns not included in the index are often the most useful kind of predicate, and we have to duplicate (or at least imply) the predicate in the WHERE clause in order to get the index to be considered at all. So index-only scans were essentially unavailable with such partial indexes. To fix, we have to do detection of implied-by-predicate clauses much earlier in the planner. This patch puts it in check_index_predicates (nee check_partial_indexes), meaning it gets done for every partial index, whereas we previously only considered this issue at createplan time, so that the work was only done for an index actually selected for use. That could result in a noticeable planning slowdown for queries against tables with many partial indexes. However, testing suggested that there isn't really a significant cost, especially not with reasonable numbers of partial indexes. We do get a small additional benefit, which is that cost_index is more accurate since it correctly discounts the evaluation cost of clauses that will be removed. We can also avoid considering such clauses as potential indexquals, which saves useless matching cycles in the case where the predicate columns aren't in the index, and prevents generating bogus plans that double-count the clause's selectivity when the columns are in the index. Tomas Vondra and Kyotaro Horiguchi, reviewed by Kevin Grittner and Konstantin Knizhnik, and whacked around a little by me
* Rethink representation of PathTargets.Tom Lane2016-03-14
| | | | | | | | | | | | | | In commit 19a541143a09c067 I did not make PathTarget a subtype of Node, and embedded a RelOptInfo's reltarget directly into it rather than having a separately-allocated Node. In hindsight that was misguided micro-optimization, enabled by the fact that at that point we didn't have any Paths with custom PathTargets. Now that PathTarget processing has been fleshed out some more, it's easier to see that it's better to have PathTarget as an indepedent Node type, even if it does cost us one more palloc to create a RelOptInfo. So change it while we still can. This commit just changes the representation, without doing anything more interesting than that.
* Add an explicit representation of the output targetlist to Paths.Tom Lane2016-02-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Up to now, there's been an assumption that all Paths for a given relation compute the same output column set (targetlist). However, there are good reasons to remove that assumption. For example, an indexscan on an expression index might be able to return the value of an expensive function "for free". While we have the ability to generate such a plan today in simple cases, we don't have a way to model that it's cheaper than a plan that computes the function from scratch, nor a way to create such a plan in join cases (where the function computation would normally happen at the topmost join node). Also, we need this so that we can have Paths representing post-scan/join steps, where the targetlist may well change from one step to the next. Therefore, invent a "struct PathTarget" representing the columns we expect a plan step to emit. It's convenient to include the output tuple width and tlist evaluation cost in this struct, and there will likely be additional fields in future. While Path nodes that actually do have custom outputs will need their own PathTargets, it will still be true that most Paths for a given relation will compute the same tlist. To reduce the overhead added by this patch, keep a "default PathTarget" in RelOptInfo, and allow Paths that compute that column set to just point to their parent RelOptInfo's reltarget. (In the patch as committed, actually every Path is like that, since we do not yet have any cases of custom PathTargets.) I took this opportunity to provide some more-honest costing of PlaceHolderVar evaluation. Up to now, the assumption that "scan/join reltargetlists have cost zero" was applied not only to Vars, where it's reasonable, but also PlaceHolderVars where it isn't. Now, we add the eval cost of a PlaceHolderVar's expression to the first plan level where it can be computed, by including it in the PathTarget cost field and adding that to the cost estimates for Paths. This isn't perfect yet but it's much better than before, and there is a way forward to improve it more. This costing change affects the join order chosen for a couple of the regression tests, changing expected row ordering.
* Update copyright for 2016Bruce Momjian2016-01-02
| | | | Backpatch certain files through 9.1
* Collection of typo fixes.Heikki Linnakangas2015-05-20
| | | | | | | | | | | | | | | Use "a" and "an" correctly, mostly in comments. Two error messages were also fixed (they were just elogs, so no translation work required). Two function comments in pg_proc.h were also fixed. Etsuro Fujita reported one of these, but I found a lot more with grep. Also fix a few other typos spotted while grepping for the a/an typos. For example, "consists out of ..." -> "consists of ...". Plus a "though"/ "through" mixup reported by Euler Taveira. Many of these typos were in old code, which would be nice to backpatch to make future backpatching easier. But much of the code was new, and I didn't feel like crafting separate patches for each branch. So no backpatching.
* 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
* Move strategy numbers to include/access/stratnum.hAlvaro Herrera2015-05-15
| | | | | | | | | | | | | | | | | | | | For upcoming BRIN opclasses, it's convenient to have strategy numbers defined in a single place. Since there's nothing appropriate, create it. The StrategyNumber typedef now lives there, as well as existing strategy numbers for B-trees (from skey.h) and R-tree-and-friends (from gist.h). skey.h is forced to include stratnum.h because of the StrategyNumber typedef, but gist.h is not; extensions that currently rely on gist.h for rtree strategy numbers might need to add a new A few .c files can stop including skey.h and/or gist.h, which is a nice side benefit. Per discussion: https://www.postgresql.org/message-id/20150514232132.GZ2523@alvh.no-ip.org Authored by Emre Hasegeli and Álvaro. (It's not clear to me why bootscanner.l has any #include lines at all.)
* Add support for index-only scans in GiST.Heikki Linnakangas2015-03-26
| | | | | | | | | | | | | | This adds a new GiST opclass method, 'fetch', which is used to reconstruct the original Datum from the value stored in the index. Also, the 'canreturn' index AM interface function gains a new 'attno' argument. That makes it possible to use index-only scans on a multi-column index where some of the opclasses support index-only scans but some do not. This patch adds support in the box and point opclasses. Other opclasses can added later as follow-on patches (btree_gist would be particularly interesting). Anastasia Lubennikova, with additional fixes and modifications by me.