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2011-10-23Don't trust deferred-unique indexes for join removal.Tom Lane
The uniqueness condition might fail to hold intra-transaction, and assuming it does can give incorrect query results. Per report from Marti Raudsepp, though this is not his proposed patch. Back-patch to 9.0, where both these features were introduced. In the released branches, add the new IndexOptInfo field to the end of the struct, to try to minimize ABI breakage for third-party code that may be examining that struct.
2011-10-14Measure the number of all-visible pages for use in index-only scan costing.Tom Lane
Add a column pg_class.relallvisible to remember the number of pages that were all-visible according to the visibility map as of the last VACUUM (or ANALYZE, or some other operations that update pg_class.relpages). Use relallvisible/relpages, instead of an arbitrary constant, to estimate how many heap page fetches can be avoided during an index-only scan. This is pretty primitive and will no doubt see refinements once we've acquired more field experience with the index-only scan mechanism, but it's way better than using a constant. Note: I had to adjust an underspecified query in the window.sql regression test, because it was changing answers when the plan changed to use an index-only scan. Some of the adjacent tests perhaps should be adjusted as well, but I didn't do that here.
2011-10-11Rearrange the implementation of index-only scans.Tom Lane
This commit changes index-only scans so that data is read directly from the index tuple without first generating a faux heap tuple. The only immediate benefit is that indexes on system columns (such as OID) can be used in index-only scans, but this is necessary infrastructure if we are ever to support index-only scans on expression indexes. The executor is now ready for that, though the planner still needs substantial work to recognize the possibility. To do this, Vars in index-only plan nodes have to refer to index columns not heap columns. I introduced a new special varno, INDEX_VAR, to mark such Vars to avoid confusion. (In passing, this commit renames the two existing special varnos to OUTER_VAR and INNER_VAR.) This allows ruleutils.c to handle them with logic similar to what we use for subplan reference Vars. Since index-only scans are now fundamentally different from regular indexscans so far as their expression subtrees are concerned, I also chose to change them to have their own plan node type (and hence, their own executor source file).
2011-10-07Support index-only scans using the visibility map to avoid heap fetches.Tom Lane
When a btree index contains all columns required by the query, and the visibility map shows that all tuples on a target heap page are visible-to-all, we don't need to fetch that heap page. This patch depends on the previous patches that made the visibility map reliable. There's a fair amount left to do here, notably trying to figure out a less chintzy way of estimating the cost of an index-only scan, but the core functionality seems ready to commit. Robert Haas and Ibrar Ahmed, with some previous work by Heikki Linnakangas.
2011-09-11Remove many -Wcast-qual warningsPeter Eisentraut
This addresses only those cases that are easy to fix by adding or moving a const qualifier or removing an unnecessary cast. There are many more complicated cases remaining.
2011-09-04Can't print PlannerGlobal's subroots list in outfuncs.Tom Lane
Since the subroots will surely link back to the same glob struct, this necessarily leads to infinite recursion. Doh. Found while trying to debug some other code.
2011-09-03Rearrange planner to save the whole PlannerInfo (subroot) for a subquery.Tom Lane
Formerly, set_subquery_pathlist and other creators of plans for subqueries saved only the rangetable and rowMarks lists from the lower-level PlannerInfo. But there's no reason not to remember the whole PlannerInfo, and indeed this turns out to simplify matters in a number of places. The immediate reason for doing this was so that the subroot will still be accessible when we're trying to extract column statistics out of an already-planned subquery. But now that I've done it, it seems like a good code-beautification effort in its own right. I also chose to get rid of the transient subrtable and subrowmark fields in SubqueryScan nodes, in favor of having setrefs.c look up the subquery's RelOptInfo. That required changing all the APIs in setrefs.c to pass PlannerInfo not PlannerGlobal, which was a large but quite mechanical transformation. One side-effect not foreseen at the beginning is that this finally broke inheritance_planner's assumption that replanning the same subquery RTE N times would necessarily give interchangeable results each time. That assumption was always pretty risky, but now we really have to make a separate RTE for each instance so that there's a place to carry the separate subroots.
2011-09-01Remove unnecessary #include references, per pgrminclude script.Bruce Momjian
2011-08-20Fix performance problem when building a lossy tidbitmap.Tom Lane
As pointed out by Sergey Koposov, repeated invocations of tbm_lossify can make building a large tidbitmap into an O(N^2) operation. To fix, make sure we remove more than the minimum amount of information per call, and add a fallback path to behave sanely if we're unable to fit the bitmap within the requested amount of memory. This has been wrong since the tidbitmap code was written, so back-patch to all supported branches.
2011-08-16Revise sinval code to remove no-longer-used tuple TID from inval messages.Tom Lane
This requires adjusting the API for syscache callback functions: they now get a hash value, not a TID, to identify the target tuple. Most of them weren't paying any attention to that argument anyway, but plancache did require a small amount of fixing. Also, improve performance a trifle by avoiding sending duplicate inval messages when a heap_update isn't changing the catcache lookup columns.
2011-08-05Allow per-column foreign data wrapper options.Robert Haas
Shigeru Hanada, with fairly minor editing by me.
2011-07-18Avoid index rebuild for no-rewrite ALTER TABLE .. ALTER TYPE.Robert Haas
Noah Misch. Review and minor cosmetic changes by me.
2011-07-16Replace errdetail("%s", ...) with errdetail_internal("%s", ...).Tom Lane
There may be some other places where we should use errdetail_internal, but they'll have to be evaluated case-by-case. This commit just hits a bunch of places where invoking gettext is obviously a waste of cycles.
2011-06-16Avoid compiler warnings due to possibly unused variablesPeter Eisentraut
gcc 4.6 complains about these because of the new option -Wunused-but-set-variable which comes in with -Wall, so cast them to void, which avoids the warning.
2011-04-18Fix handling of collations in multi-row VALUES constructs.Tom Lane
Per spec we ought to apply select_common_collation() across the expressions in each column of the VALUES table. The original coding was just taking the first row and assuming it was representative. This patch adds a field to struct RangeTblEntry to carry the resolved collations, so initdb is forced for changes in stored rule representation.
2011-04-10pgindent run before PG 9.1 beta 1.Bruce Momjian
2011-03-26More collations cleanup, from trawling for missed collation assignments.Tom Lane
Mostly cosmetic, though I did find that generateClonedIndexStmt failed to clone the index's collations.
2011-03-25Pass collation to makeConst() instead of looking it up internally.Tom Lane
In nearly all cases, the caller already knows the correct collation, and in a number of places, the value the caller has handy is more correct than the default for the type would be. (In particular, this patch makes it significantly less likely that eval_const_expressions will result in changing the exposed collation of an expression.) So an internal lookup is both expensive and wrong.
2011-03-22Make FKs valid at creation when added as column constraints.Simon Riggs
Bug report from Alvaro Herrera
2011-03-22Reimplement planner's handling of MIN/MAX aggregate optimization (again).Tom Lane
Instead of playing cute games with pathkeys, just build a direct representation of the intended sub-select, and feed it through query_planner to get a Path for the index access. This is a bit slower than 9.1's previous method, since we'll duplicate most of the overhead of query_planner; but since the whole optimization only applies to rather simple single-table queries, that probably won't be much of a problem in practice. The advantage is that we get to do the right thing when there's a partial index that needs the implicit IS NOT NULL clause to be usable. Also, although this makes planagg.c be a bit more closely tied to the ordering of operations in grouping_planner, we can get rid of some coupling to lower-level parts of the planner. Per complaint from Marti Raudsepp.
2011-03-19Revise collation derivation method and expression-tree representation.Tom Lane
All expression nodes now have an explicit output-collation field, unless they are known to only return a noncollatable data type (such as boolean or record). Also, nodes that can invoke collation-aware functions store a separate field that is the collation value to pass to the function. This avoids confusion that arises when a function has collatable inputs and noncollatable output type, or vice versa. Also, replace the parser's on-the-fly collation assignment method with a post-pass over the completed expression tree. This allows us to use a more complex (and hopefully more nearly spec-compliant) assignment rule without paying for it in extra storage in every expression node. Fix assorted bugs in the planner's handling of collations by making collation one of the defining properties of an EquivalenceClass and by converting CollateExprs into discardable RelabelType nodes during expression preprocessing.
2011-03-11Split CollateClause into separate raw and analyzed node types.Tom Lane
CollateClause is now used only in raw grammar output, and CollateExpr after parse analysis. This is for clarity and to avoid carrying collation names in post-analysis parse trees: that's both wasteful and possibly misleading, since the collation's name could be changed while the parsetree still exists. Also, clean up assorted infelicities and omissions in processing of the node type.
2011-03-09Remove collation information from TypeName, where it does not belong.Tom Lane
The initial collations patch treated a COLLATE spec as part of a TypeName, following what can only be described as brain fade on the part of the SQL committee. It's a lot more reasonable to treat COLLATE as a syntactically separate object, so that it can be added in only the productions where it actually belongs, rather than needing to reject it in a boatload of places where it doesn't belong (something the original patch mostly failed to do). In addition this change lets us meet the spec's requirement to allow COLLATE anywhere in the clauses of a ColumnDef, and it avoids unfriendly behavior for constructs such as "foo::type COLLATE collation". To do this, pull collation information out of TypeName and put it in ColumnDef instead, thus reverting most of the collation-related changes in parse_type.c's API. I made one additional structural change, which was to use a ColumnDef as an intermediate node in AT_AlterColumnType AlterTableCmd nodes. This provides enough room to get rid of the "transform" wart in AlterTableCmd too, since the ColumnDef can carry the USING expression easily enough. Also fix some other minor bugs that have crept in in the same areas, like failure to copy recently-added fields of ColumnDef in copyfuncs.c. While at it, document the formerly secret ability to specify a collation in ALTER TABLE ALTER COLUMN TYPE, ALTER TYPE ADD ATTRIBUTE, and ALTER TYPE ALTER ATTRIBUTE TYPE; and correct some misstatements about what the default collation selection will be when COLLATE is omitted. BTW, the three-parameter form of format_type() should go away too, since it just contributes to the confusion in this area; but I'll do that in a separate patch.
2011-03-04Allow non-superusers to create (some) extensions.Tom Lane
Remove the unconditional superuser permissions check in CREATE EXTENSION, and instead define a "superuser" extension property, which when false (not the default) skips the superuser permissions check. In this case the calling user only needs enough permissions to execute the commands in the extension's installation script. The superuser property is also enforced in the same way for ALTER EXTENSION UPDATE cases. In other ALTER EXTENSION cases and DROP EXTENSION, test ownership of the extension rather than superuserness. ALTER EXTENSION ADD/DROP needs to insist on ownership of the target object as well; to do that without duplicating code, refactor comment.c's big switch for permissions checks into a separate function in objectaddress.c. I also removed the superuserness checks in pg_available_extensions and related functions; there's no strong reason why everybody shouldn't be able to see that info. Also invent an IF NOT EXISTS variant of CREATE EXTENSION, and use that in pg_dump, so that dumps won't fail for installed-by-default extensions. We don't have any of those yet, but we will soon. This is all per discussion of wrapping the standard procedural languages into extensions. I'll make those changes in a separate commit; this is just putting the core infrastructure in place.
2011-02-25Support data-modifying commands (INSERT/UPDATE/DELETE) in WITH.Tom Lane
This patch implements data-modifying WITH queries according to the semantics that the updates all happen with the same command counter value, and in an unspecified order. Therefore one WITH clause can't see the effects of another, nor can the outer query see the effects other than through the RETURNING values. And attempts to do conflicting updates will have unpredictable results. We'll need to document all that. This commit just fixes the code; documentation updates are waiting on author. Marko Tiikkaja and Hitoshi Harada
2011-02-22Add a relkind field to RangeTblEntry to avoid some syscache lookups.Tom Lane
The recent additions for FDW support required checking foreign-table-ness in several places in the parse/plan chain. While it's not clear whether that would really result in a noticeable slowdown, it seems best to avoid any performance risk by keeping a copy of the relation's relkind in RangeTblEntry. That might have some other uses later, anyway. Per discussion.
2011-02-20Implement an API to let foreign-data wrappers actually be functional.Tom Lane
This commit provides the core code and documentation needed. A contrib module test case will follow shortly. Shigeru Hanada, Jan Urbanski, Heikki Linnakangas
2011-02-19Create the catalog infrastructure for foreign-data-wrapper handlers.Tom Lane
Add a fdwhandler column to pg_foreign_data_wrapper, plus HANDLER options in the CREATE FOREIGN DATA WRAPPER and ALTER FOREIGN DATA WRAPPER commands, plus pg_dump support for same. Also invent a new pseudotype fdw_handler with properties similar to language_handler. This is split out of the "FDW API" patch for ease of review; it's all stuff we will certainly need, regardless of any other details of the FDW API. FDW handler functions will not actually get called yet. In passing, fix some omissions and infelicities in foreigncmds.c. Shigeru Hanada, Jan Urbanski, Heikki Linnakangas
2011-02-16Fix bogus test for hypothetical indexes in get_actual_variable_range().Tom Lane
That function was supposing that indexoid == 0 for a hypothetical index, but that is not likely to be true in any non-toy implementation of an index adviser, since assigning a fake OID is the only way to know at EXPLAIN time which hypothetical index got selected. Fix by adding a flag to IndexOptInfo to mark hypothetical indexes. Back-patch to 9.0 where get_actual_variable_range() was added. Gurjeet Singh
2011-02-11Add support for multiple versions of an extension and ALTER EXTENSION UPDATE.Tom Lane
This follows recent discussions, so it's quite a bit different from Dimitri's original. There will probably be more changes once we get a bit of experience with it, but let's get it in and start playing with it. This is still just core code. I'll start converting contrib modules shortly. Dimitri Fontaine and Tom Lane
2011-02-10Extend "ALTER EXTENSION ADD object" to permit "DROP object" as well.Tom Lane
Per discussion, this is something we should have sooner rather than later, and it doesn't take much additional code to support it.
2011-02-09Fix improper matching of resjunk column names for FOR UPDATE in subselect.Tom Lane
Flattening of subquery range tables during setrefs.c could lead to the rangetable indexes in PlanRowMark nodes not matching up with the column names previously assigned to the corresponding resjunk ctid (resp. tableoid or wholerow) columns. Typical symptom would be either a "cannot extract system attribute from virtual tuple" error or an Assert failure. This wasn't a problem before 9.0 because we didn't support FOR UPDATE below the top query level, and so the final flattening could never renumber an RTE that was relevant to FOR UPDATE. Fix by using a plan-tree-wide unique number for each PlanRowMark to label the associated resjunk columns, so that the number need not change during flattening. Per report from David Johnston (though I'm darned if I can see how this got past initial testing of the relevant code). Back-patch to 9.0.
2011-02-09Implement "ALTER EXTENSION ADD object".Tom Lane
This is an essential component of making the extension feature usable; first because it's needed in the process of converting an existing installation containing "loose" objects of an old contrib module into the extension-based world, and second because we'll have to use it in pg_dump --binary-upgrade, as per recent discussion. Loosely based on part of Dimitri Fontaine's ALTER EXTENSION UPGRADE patch.
2011-02-08Core support for "extensions", which are packages of SQL objects.Tom Lane
This patch adds the server infrastructure to support extensions. There is still one significant loose end, namely how to make it play nice with pg_upgrade, so I am not yet committing the changes that would make all the contrib modules depend on this feature. In passing, fix a disturbingly large amount of breakage in AlterObjectNamespace() and callers. Dimitri Fontaine, reviewed by Anssi Kääriäinen, Itagaki Takahiro, Tom Lane, and numerous others
2011-02-08Per-column collation supportPeter Eisentraut
This adds collation support for columns and domains, a COLLATE clause to override it per expression, and B-tree index support. Peter Eisentraut reviewed by Pavel Stehule, Itagaki Takahiro, Robert Haas, Noah Misch
2011-01-25Implement ALTER TABLE ADD UNIQUE/PRIMARY KEY USING INDEX.Tom Lane
This feature allows a unique or pkey constraint to be created using an already-existing unique index. While the constraint isn't very functionally different from the bare index, it's nice to be able to do that for documentation purposes. The main advantage over just issuing a plain ALTER TABLE ADD UNIQUE/PRIMARY KEY is that the index can be created with CREATE INDEX CONCURRENTLY, so that there is not a long interval where the table is locked against updates. On the way, refactor some of the code in DefineIndex() and index_create() so that we don't have to pass through those functions in order to create the index constraint's catalog entries. Also, in parse_utilcmd.c, pass around the ParseState pointer in struct CreateStmtContext to save on notation, and add error location pointers to some error reports that didn't have one before. Gurjeet Singh, reviewed by Steve Singer and Tom Lane
2011-01-12Fix PlanRowMark/ExecRowMark structures to handle inheritance correctly.Tom Lane
In an inherited UPDATE/DELETE, each target table has its own subplan, because it might have a column set different from other targets. This means that the resjunk columns we add to support EvalPlanQual might be at different physical column numbers in each subplan. The EvalPlanQual rewrite I did for 9.0 failed to account for this, resulting in possible misbehavior or even crashes during concurrent updates to the same row, as seen in a recent report from Gordon Shannon. Revise the data structure so that we track resjunk column numbers separately for each subplan. I also chose to move responsibility for identifying the physical column numbers back to executor startup, instead of assuming that numbers derived during preprocess_targetlist would stay valid throughout subsequent massaging of the plan. That's a bit slower, so we might want to consider undoing it someday; but it would complicate the patch considerably and didn't seem justifiable in a bug fix that has to be back-patched to 9.0.
2011-01-01Basic foreign table support.Robert Haas
Foreign tables are a core component of SQL/MED. This commit does not provide a working SQL/MED infrastructure, because foreign tables cannot yet be queried. Support for foreign table scans will need to be added in a future patch. However, this patch creates the necessary system catalog structure, syntax support, and support for ancillary operations such as COMMENT and SECURITY LABEL. Shigeru Hanada, heavily revised by Robert Haas
2011-01-01Stamp copyrights for year 2011.Bruce Momjian
2010-12-21Use memcmp() rather than strncmp() when shorter string length is known.Robert Haas
It appears that this will be faster for all but the shortest strings; at least one some platforms, memcmp() can use word-at-a-time comparisons. Noah Misch, somewhat pared down.
2010-12-13Generalize concept of temporary relations to "relation persistence".Robert Haas
This commit replaces pg_class.relistemp with pg_class.relpersistence; and also modifies the RangeVar node type to carry relpersistence rather than istemp. It also removes removes rd_istemp from RelationData and instead performs the correct computation based on relpersistence. For clarity, we add three new macros: RelationNeedsWAL(), RelationUsesLocalBuffers(), and RelationUsesTempNamespace(), so that we can clarify the purpose of each check that previous depended on rd_istemp. This is intended as infrastructure for the upcoming unlogged tables patch, as well as for future possible work on global temporary tables.
2010-12-06Add a stack overflow check to copyObject().Tom Lane
There are some code paths, such as SPI_execute(), where we invoke copyObject() on raw parse trees before doing parse analysis on them. Since the bison grammar is capable of building heavily nested parsetrees while itself using only minimal stack depth, this means that copyObject() can be the front-line function that hits stack overflow before anything else does. Accordingly, it had better have a check_stack_depth() call. I did a bit of performance testing and found that this slows down copyObject() by only a few percent, so the hit ought to be negligible in the context of complete processing of a query. Per off-list report from Toshihide Katayama. Back-patch to all supported branches.
2010-12-02Create core infrastructure for KNNGIST.Tom Lane
This is a heavily revised version of builtin_knngist_core-0.9. The ordering operators are no longer mixed in with actual quals, which would have confused not only humans but significant parts of the planner. Instead, ordering operators are carried separately throughout planning and execution. Since the API for ambeginscan and amrescan functions had to be changed anyway, this commit takes the opportunity to rationalize that a bit. RelationGetIndexScan no longer forces a premature index_rescan call; instead, callers of index_beginscan must call index_rescan too. Aside from making the AM-side initialization logic a bit less peculiar, this has the advantage that we do not make a useless extra am_rescan call when there are runtime key values. AMs formerly could not assume that the key values passed to amrescan were actually valid; now they can. Teodor Sigaev and Tom Lane
2010-11-24Create the system catalog infrastructure needed for KNNGIST.Tom Lane
This commit adds columns amoppurpose and amopsortfamily to pg_amop, and column amcanorderbyop to pg_am. For the moment all the entries in amcanorderbyop are "false", since the underlying support isn't there yet. Also, extend the CREATE OPERATOR CLASS/ALTER OPERATOR FAMILY commands with [ FOR SEARCH | FOR ORDER BY sort_operator_family ] clauses to allow the new columns of pg_amop to be populated, and create pg_dump support for dumping that information. I also added some documentation, although it's perhaps a bit premature given that the feature doesn't do anything useful yet. Teodor Sigaev, Robert Haas, Tom Lane
2010-11-23Propagate ALTER TYPE operations to typed tablesPeter Eisentraut
This adds RESTRICT/CASCADE flags to ALTER TYPE ... ADD/DROP/ALTER/ RENAME ATTRIBUTE to control whether to alter typed tables as well.
2010-11-23Remove useless whitespace at end of linesPeter Eisentraut
2010-11-18Further fallout from the MergeAppend patch.Tom Lane
Fix things so that top-N sorting can be used in child Sort nodes of a MergeAppend node, when there is a LIMIT and no intervening joins or grouping. Actually doing this on the executor side isn't too bad, but it's a bit messier to get the planner to cost it properly. Per gripe from Robert Haas. In passing, fix an oversight in the original top-N-sorting patch: query_planner should not assume that a LIMIT can be used to make an explicit sort cheaper when there will be grouping or aggregation in between. Possibly this should be back-patched, but I'm not sure the mistake is serious enough to be a real problem in practice.
2010-11-13Add missing outfuncs.c support for struct InhRelation.Tom Lane
This is needed to support debug_print_parse, per report from Jon Nelson. Cursory testing via the regression tests suggests we aren't missing anything else.
2010-11-04Reimplement planner's handling of MIN/MAX aggregate optimization.Tom Lane
Per my recent proposal, get rid of all the direct inspection of indexes and manual generation of paths in planagg.c. Instead, set up EquivalenceClasses for the aggregate argument expressions, and let the regular path generation logic deal with creating paths that can satisfy those sort orders. This makes planagg.c a bit more visible to the rest of the planner than it was originally, but the approach is basically a lot cleaner than before. A major advantage of doing it this way is that we get MIN/MAX optimization on inheritance trees (using MergeAppend of indexscans) practically for free, whereas in the old way we'd have had to add a whole lot more duplicative logic. One small disadvantage of this approach is that MIN/MAX aggregates can no longer exploit partial indexes having an "x IS NOT NULL" predicate, unless that restriction or something that implies it is specified in the query. The previous implementation was able to use the added "x IS NOT NULL" condition as an extra predicate proof condition, but in this version we rely entirely on indexes that are considered usable by the main planning process. That seems a fair tradeoff for the simplicity and functionality gained.
2010-10-30Provide hashing support for arrays.Tom Lane
The core of this patch is hash_array() and associated typcache infrastructure, which works just about exactly like the existing support for array comparison. In addition I did some work to ensure that the planner won't think that an array type is hashable unless its element type is hashable, and similarly for sorting. This includes adding a datatype parameter to op_hashjoinable and op_mergejoinable, and adding an explicit "hashable" flag to SortGroupClause. The lack of a cross-check on the element type was a pre-existing bug in mergejoin support --- but it didn't matter so much before, because if you couldn't sort the element type there wasn't any good alternative to failing anyhow. Now that we have the alternative of hashing the array type, there are cases where we can avoid a failure by being picky at the planner stage, so it's time to be picky. The issue of exactly how to combine the per-element hash values to produce an array hash is still open for discussion, but the rest of this is pretty solid, so I'll commit it as-is.