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* Add some infrastructure for contrib/pg_stat_statements.Tom Lane2012-03-27
| | | | | | | | | | | | | | | | | | | | Add a queryId field to Query and PlannedStmt. This is not used by the core backend, except for being copied around at appropriate times. It's meant to allow plug-ins to track a particular query forward from parse analysis to execution. The queryId is intentionally not dumped into stored rules (and hence this commit doesn't bump catversion). You could argue that choice either way, but it seems better that stored rule strings not have any dependency on plug-ins that might or might not be present. Also, add a post_parse_analyze_hook that gets invoked at the end of parse analysis (but only for top-level analysis of complete queries, not cases such as analyzing a domain's default-value expression). This is mainly meant to be used to compute and assign a queryId, but it could have other applications. Peter Geoghegan
* New GUC, track_iotiming, to track I/O timings.Robert Haas2012-03-27
| | | | | | | | Currently, the only way to see the numbers this gathers is via EXPLAIN (ANALYZE, BUFFERS), but the plan is to add visibility through the stats collector and pg_stat_statements in subsequent patches. Ants Aasma, reviewed by Greg Smith, with some further changes by me.
* Code cleanup for heap_freeze_tuple.Robert Haas2012-03-26
| | | | | | | It used to be case that lazy vacuum could call this function with only a shared lock on the buffer, but neither lazy vacuum nor any other code path does that any more. Simplify the code accordingly and clean up some related, obsolete comments.
* Replace empty locale name with implied value in CREATE DATABASE and initdb.Tom Lane2012-03-25
| | | | | | | | | | | | | | | | | | | | | | | | | setlocale() accepts locale name "" as meaning "the locale specified by the process's environment variables". Historically we've accepted that for Postgres' locale settings, too. However, it's fairly unsafe to store an empty string in a new database's pg_database.datcollate or datctype fields, because then the interpretation could vary across postmaster restarts, possibly resulting in index corruption and other unpleasantness. Instead, we should expand "" to whatever it means at the moment of calling CREATE DATABASE, which we can do by saving the value returned by setlocale(). For consistency, make initdb set up the initial lc_xxx parameter values the same way. initdb was already doing the right thing for empty locale names, but it did not replace non-empty names with setlocale results. On a platform where setlocale chooses to canonicalize the spellings of locale names, this would result in annoying inconsistency. (It seems that popular implementations of setlocale don't do such canonicalization, which is a pity, but the POSIX spec certainly allows it to be done.) The same risk of inconsistency leads me to not venture back-patching this, although it could certainly be seen as a longstanding bug. Per report from Jeff Davis, though this is not his proposed patch.
* Fix planner's handling of outer PlaceHolderVars within subqueries.Tom Lane2012-03-24
| | | | | | | | | | | | | | | | | | | | | | | For some reason, in the original coding of the PlaceHolderVar mechanism I had supposed that PlaceHolderVars couldn't propagate into subqueries. That is of course entirely possible. When it happens, we need to treat an outer-level PlaceHolderVar much like an outer Var or Aggref, that is SS_replace_correlation_vars() needs to replace the PlaceHolderVar with a Param, and then when building the finished SubPlan we have to provide the PlaceHolderVar expression as an actual parameter for the SubPlan. The handling of the contained expression is a bit delicate but it can be treated exactly like an Aggref's expression. In addition to the missing logic in subselect.c, prepjointree.c was failing to search subqueries for PlaceHolderVars that need their relids adjusted during subquery pullup. It looks like everyplace else that touches PlaceHolderVars got it right, though. Per report from Mark Murawski. In 9.1 and HEAD, queries affected by this oversight would fail with "ERROR: Upper-level PlaceHolderVar found where not expected". But in 9.0 and 8.4, you'd silently get possibly-wrong answers, since the value transmitted into the subquery wouldn't go to null when it should.
* Code review for protransform patches.Tom Lane2012-03-23
| | | | | | | | | | | | | | | | | Fix loss of previous expression-simplification work when a transform function fires: we must not simply revert to untransformed input tree. Instead build a dummy FuncExpr node to pass to the transform function. This has the additional advantage of providing a simpler, more uniform API for transform functions. Move documentation to a somewhat less buried spot, relocate some poorly-placed code, be more wary of null constants and invalid typmod values, add an opr_sanity check on protransform function signatures, and some other minor cosmetic adjustments. Note: although this patch touches pg_proc.h, no need for catversion bump, because the changes are cosmetic and don't actually change the intended catalog contents.
* Clean up compiler warnings from unused variables with asserts disabledPeter Eisentraut2012-03-21
| | | | | | For those variables only used when asserts are enabled, use a new macro PG_USED_FOR_ASSERTS_ONLY, which expands to __attribute__((unused)) when asserts are not enabled.
* Restructure SELECT INTO's parsetree representation into CreateTableAsStmt.Tom Lane2012-03-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | Making this operation look like a utility statement seems generally a good idea, and particularly so in light of the desire to provide command triggers for utility statements. The original choice of representing it as SELECT with an IntoClause appendage had metastasized into rather a lot of places, unfortunately, so that this patch is a great deal more complicated than one might at first expect. In particular, keeping EXPLAIN working for SELECT INTO and CREATE TABLE AS subcommands required restructuring some EXPLAIN-related APIs. Add-on code that calls ExplainOnePlan or ExplainOneUtility, or uses ExplainOneQuery_hook, will need adjustment. Also, the cases PREPARE ... SELECT INTO and CREATE RULE ... SELECT INTO, which formerly were accepted though undocumented, are no longer accepted. The PREPARE case can be replaced with use of CREATE TABLE AS EXECUTE. The CREATE RULE case doesn't seem to have much real-world use (since the rule would work only once before failing with "table already exists"), so we'll not bother with that one. Both SELECT INTO and CREATE TABLE AS still return a command tag of "SELECT nnnn". There was some discussion of returning "CREATE TABLE nnnn", but for the moment backwards compatibility wins the day. Andres Freund and Tom Lane
* Revisit handling of UNION ALL subqueries with non-Var output columns.Tom Lane2012-03-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In commit 57664ed25e5dea117158a2e663c29e60b3546e1c I tried to fix a bug reported by Teodor Sigaev by making non-simple-Var output columns distinct (by wrapping their expressions with dummy PlaceHolderVar nodes). This did not work too well. Commit b28ffd0fcc583c1811e5295279e7d4366c3cae6c fixed some ensuing problems with matching to child indexes, but per a recent report from Claus Stadler, constraint exclusion of UNION ALL subqueries was still broken, because constant-simplification didn't handle the injected PlaceHolderVars well either. On reflection, the original patch was quite misguided: there is no reason to expect that EquivalenceClass child members will be distinct. So instead of trying to make them so, we should ensure that we can cope with the situation when they're not. Accordingly, this patch reverts the code changes in the above-mentioned commits (though the regression test cases they added stay). Instead, I've added assorted defenses to make sure that duplicate EC child members don't cause any problems. Teodor's original problem ("MergeAppend child's targetlist doesn't match MergeAppend") is addressed more directly by revising prepare_sort_from_pathkeys to let the parent MergeAppend's sort list guide creation of each child's sort list. In passing, get rid of add_sort_column; as far as I can tell, testing for duplicate sort keys at this stage is dead code. Certainly it doesn't trigger often enough to be worth expending cycles on in ordinary queries. And keeping the test would've greatly complicated the new logic in prepare_sort_from_pathkeys, because comparing pathkey list entries against a previous output array requires that we not skip any entries in the list. Back-patch to 9.1, like the previous patches. The only known issue in this area that wasn't caused by the ill-advised previous patches was the MergeAppend planning failure, which of course is not relevant before 9.1. It's possible that we need some of the new defenses against duplicate child EC entries in older branches, but until there's some clear evidence of that I'm going to refrain from back-patching further.
* Add comments explaining why our Itanium spinlock implementation is safe.Heikki Linnakangas2012-03-16
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* Add const qualifier to tzn returned by timestamp2tm()Peter Eisentraut2012-03-15
| | | | | The tzn value might come from tm->tm_zone, which libc declares as const, so it's prudent that the upper layers know about this as well.
* Improve EncodeDateTime and EncodeTimeOnly APIsPeter Eisentraut2012-03-14
| | | | | Use an explicit argument to tell whether to include the time zone in the output, rather than using some undocumented pointer magic.
* Teach SPGiST to store nulls and do whole-index scans.Tom Lane2012-03-11
| | | | | | | | | | | | | | | | | | | | | This patch fixes the other major compatibility-breaking limitation of SPGiST, that it didn't store anything for null values of the indexed column, and so could not support whole-index scans or "x IS NULL" tests. The approach is to create a wholly separate search tree for the null entries, and use fixed "allTheSame" insertion and search rules when processing this tree, instead of calling the index opclass methods. This way the opclass methods do not need to worry about dealing with nulls. Catversion bump is for pg_am updates as well as the change in on-disk format of SPGiST indexes; there are some tweaks in SPGiST WAL records as well. Heavily rewritten version of a patch by Oleg Bartunov and Teodor Sigaev. (The original also stored nulls separately, but it reused GIN code to do so; which required undesirable compromises in the on-disk format, and would likely lead to bugs due to the GIN code being required to work in two very different contexts.)
* Restructure SPGiST opclass interface API to support whole-index scans.Tom Lane2012-03-10
| | | | | | | | | | | | | | | | | | | | The original API definition was incapable of supporting whole-index scans because there was no way to invoke leaf-value reconstruction without checking any qual conditions. Also, it was inefficient for multiple-qual-condition scans because value reconstruction got done over again for each qual condition, and because other internal work in the consistent functions likewise had to be done for each qual. To fix these issues, pass the whole scankey array to the opclass consistent functions, instead of only letting them see one item at a time. (Essentially, the loop over scankey entries is now inside the consistent functions not outside them. This makes the consistent functions a bit more complicated, but not unreasonably so.) In itself this commit does nothing except save a few cycles in multiple-qual-condition index scans, since we can't support whole-index scans on SPGiST indexes until nulls are included in the index. However, I consider this a must-fix for 9.2 because once we release it will get very much harder to change the opclass API definition.
* Add support for renaming constraintsPeter Eisentraut2012-03-10
| | | | reviewed by Josh Berkus and Dimitri Fontaine
* Extend object access hook framework to support arguments, and DROP.Robert Haas2012-03-09
| | | | | | | | | This allows loadable modules to get control at drop time, perhaps for the purpose of performing additional security checks or to log the event. The initial purpose of this code is to support sepgsql, but other applications should be possible as well. KaiGai Kohei, reviewed by me.
* Revise FDW planning API, again.Tom Lane2012-03-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Further reflection shows that a single callback isn't very workable if we desire to let FDWs generate multiple Paths, because that forces the FDW to do all work necessary to generate a valid Plan node for each Path. Instead split the former PlanForeignScan API into three steps: GetForeignRelSize, GetForeignPaths, GetForeignPlan. We had already bit the bullet of breaking the 9.1 FDW API for 9.2, so this shouldn't cause very much additional pain, and it's substantially more flexible for complex FDWs. Add an fdw_private field to RelOptInfo so that the new functions can save state there rather than possibly having to recalculate information two or three times. In addition, we'd not thought through what would be needed to allow an FDW to set up subexpressions of its choice for runtime execution. We could treat ForeignScan.fdw_private as an executable expression but that seems likely to break existing FDWs unnecessarily (in particular, it would restrict the set of node types allowable in fdw_private to those supported by expression_tree_walker). Instead, invent a separate field fdw_exprs which will receive the postprocessing appropriate for expression trees. (One field is enough since it can be a list of expressions; also, we assume the corresponding expression state tree(s) will be held within fdw_state, so we don't need to add anything to ForeignScanState.) Per review of Hanada Shigeru's pgsql_fdw patch. We may need to tweak this further as we continue to work on that patch, but to me it feels a lot closer to being right now.
* Fix some issues with temp/transient tables in extension scripts.Tom Lane2012-03-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Phil Sorber reported that a rewriting ALTER TABLE within an extension update script failed, because it creates and then drops a placeholder table; the drop was being disallowed because the table was marked as an extension member. We could hack that specific case but it seems likely that there might be related cases now or in the future, so the most practical solution seems to be to create an exception to the general rule that extension member objects can only be dropped by dropping the owning extension. To wit: if the DROP is issued within the extension's own creation or update scripts, we'll allow it, implicitly performing an "ALTER EXTENSION DROP object" first. This will simplify cases such as extension downgrade scripts anyway. No docs change since we don't seem to have documented the idea that you would need ALTER EXTENSION DROP for such an action to begin with. Also, arrange for explicitly temporary tables to not get linked as extension members in the first place, and the same for the magic pg_temp_nnn schemas that are created to hold them. This prevents assorted unpleasant results if an extension script creates a temp table: the forced drop at session end would either fail or remove the entire extension, and neither of those outcomes is desirable. Note that this doesn't fix the ALTER TABLE scenario, since the placeholder table is not temp (unless the table being rewritten is). Back-patch to 9.1.
* Add GetForeignColumnOptions() to foreign.c, and add some documentation.Tom Lane2012-03-07
| | | | | | | | | | | | | | | | GetForeignColumnOptions provides some abstraction for accessing column-specific FDW options, on a par with the access functions that were already provided here for other FDW-related information. Adjust file_fdw.c to use GetForeignColumnOptions instead of equivalent hand-rolled code. In addition, add some SGML documentation for the functions exported by foreign.c that are meant for use by FDW authors. (This is the fdw_helper portion of the proposed pgsql_fdw patch.) Hanada Shigeru, reviewed by KaiGai Kohei
* Expose an API for calculating catcache hash values.Tom Lane2012-03-07
| | | | | | | | | | | Now that cache invalidation callbacks get only a hash value, and not a tuple TID (per commits 632ae6829f7abda34e15082c91d9dfb3fc0f298b and b5282aa893e565b7844f8237462cb843438cdd5e), the only way they can restrict what they invalidate is to know what the hash values mean. setrefs.c was doing this via a hard-wired assumption but that seems pretty grotty, and it'll only get worse as more cases come up. So let's expose a calculation function that takes the same parameters as SearchSysCache. Per complaint from Marko Kreen.
* Add a hook for processing messages due to be sent to the server log.Tom Lane2012-03-06
| | | | | | | | | | | | Use-cases for this include custom log filtering rules and custom log message transmission mechanisms (for instance, lossy log message collection, which has been discussed several times recently). As is our common practice for hooks, there's no regression test nor user-facing documentation for this, though the author did exhibit a sample module using the hook. Martin Pihlak, reviewed by Marti Raudsepp
* Redesign PlanForeignScan API to allow multiple paths for a foreign table.Tom Lane2012-03-05
| | | | | | | | | | | The original API specification only allowed an FDW to create a single access path, which doesn't seem like a terribly good idea in hindsight. Instead, move the responsibility for building the Path node and calling add_path() into the FDW's PlanForeignScan function. Now, it can do that more than once if appropriate. There is no longer any need for the transient FdwPlan struct, so get rid of that. Etsuro Fujita, Shigeru Hanada, Tom Lane
* Add function pg_xlog_location_diff to help comparisonsMagnus Hagander2012-03-04
| | | | | | | | Comparing two xlog locations are useful for example when calculating replication lag. Euler Taveira de Oliveira, reviewed by Fujii Masao, and some cleanups from me
* Collect and use element-frequency statistics for arrays.Tom Lane2012-03-03
| | | | | | | | | | | | | | | | | | | | | | | | This patch improves selectivity estimation for the array <@, &&, and @> (containment and overlaps) operators. It enables collection of statistics about individual array element values by ANALYZE, and introduces operator-specific estimators that use these stats. In addition, ScalarArrayOpExpr constructs of the forms "const = ANY/ALL (array_column)" and "const <> ANY/ALL (array_column)" are estimated by treating them as variants of the containment operators. Since we still collect scalar-style stats about the array values as a whole, the pg_stats view is expanded to show both these stats and the array-style stats in separate columns. This creates an incompatible change in how stats for tsvector columns are displayed in pg_stats: the stats about lexemes are now displayed in the array-related columns instead of the original scalar-related columns. There are a few loose ends here, notably that it'd be nice to be able to suppress either the scalar-style stats or the array-element stats for columns for which they're not useful. But the patch is in good enough shape to commit for wider testing. Alexander Korotkov, reviewed by Noah Misch and Nathan Boley
* Add COLLATION FOR expressionPeter Eisentraut2012-03-02
| | | | reviewed by Jaime Casanova
* Remove TOAST table from pg_databaseAlvaro Herrera2012-03-01
| | | | | | | | | The only toastable column now is datacl, but we don't really support long ACLs anyway. The TOAST table should have been removed when the pg_db_role_setting catalog was introduced in commit 2eda8dfb52ed9962920282d8384da8bb4c22514d, but I forgot to do that. Per -hackers discussion on March 2011.
* Fix typo in commentAlvaro Herrera2012-02-28
| | | | Haifeng Liu
* Move CRC tables to libpgport, and provide them in a separate include file.Tom Lane2012-02-28
| | | | | | | | | | | | | | | | | | This makes it much more convenient to build tools for Postgres that are separately compiled and require a matching CRC implementation. To prevent multiple copies of the CRC polynomial tables being introduced into the postgres binaries, they are now included in the static library libpgport that is mainly meant for replacement system functions. That seems like a bit of a kludge, but there's no better place. This cleans up building of the tools pg_controldata and pg_resetxlog, which previously had to build their own copies of pg_crc.o. In the future, external programs that need access to the CRC tables can include the tables directly from the new header file pg_crc_tables.h. Daniel Farina, reviewed by Abhijit Menon-Sen and Tom Lane
* Add const qualifiers where they are accidentally cast awayPeter Eisentraut2012-02-28
| | | | | This only produces warnings under -Wcast-qual, but it's more correct and consistent in any case.
* ALTER TABLE: skip FK validation when it's safe to do soAlvaro Herrera2012-02-27
| | | | | | | | | | | | | | | | | | | | | | | | | We already skip rewriting the table in these cases, but we still force a whole table scan to validate the data. This can be skipped, and thus we can make the whole ALTER TABLE operation just do some catalog touches instead of scanning the table, when these two conditions hold: (a) Old and new pg_constraint.conpfeqop match exactly. This is actually stronger than needed; we could loosen things by way of operator families, but it'd require a lot more effort. (b) The functions, if any, implementing a cast from the foreign type to the primary opcintype are the same. For this purpose, we can consider a binary coercion equivalent to an exact type match. When the opcintype is polymorphic, require that the old and new foreign types match exactly. (Since ri_triggers.c does use the executor, the stronger check for polymorphic types is no mere future-proofing. However, no core type exercises its necessity.) Author: Noah Misch Committer's note: catalog version bumped due to change of the Constraint node. I can't actually find any way to have such a node in a stored rule, but given that we have "out" support for them, better be safe.
* Remove useless const qualifierPeter Eisentraut2012-02-26
| | | | | | | Claiming that the typevar argument to DefineCompositeType() is const was a plain lie. A similar case in DefineVirtualRelation() was already changed in passing in commit 1575fbcb. Also clean up the now unnecessary casts that used to cast away the const.
* Avoid repeated creation/freeing of per-subre DFAs during regex search.Tom Lane2012-02-24
| | | | | | | | | | | | In nested sub-regex trees, lower-level nodes created DFAs and then destroyed them again before exiting, which is a bit dumb considering that the recursive search is likely to call those nodes again later. Instead cache each created DFA until the end of pg_regexec(). This is basically a space for time tradeoff, in that it might increase the maximum memory usage. However, in most regex patterns there are not all that many subre nodes, so not that many DFAs --- and in any case, the peak usage occurs when reaching the bottom recursion level, and except for alternation cases that's going to be the same anyway.
* Remove useless "retry memory" logic within regex engine.Tom Lane2012-02-24
| | | | | | | | | | | | | | | | | | Apparently some primordial version of Spencer's engine needed cdissect() and child functions to be able to continue matching from a previous position when re-called. That is dead code, though, since trivial inspection shows that cdissect can never be entered without having previously done zapmem which resets the relevant retry counter. I have also verified experimentally that no case in the Tcl regression tests reaches cdissect with a nonzero retry value. Accordingly, remove that logic. This doesn't really save any noticeable number of cycles in itself, but it is one step towards making dissect() and cdissect() equivalent, which will allow removing hundreds of lines of near-duplicated code. Since struct subre's "retry" field is no longer particularly related to any kind of retry, rename it to "id". As of this commit it's only used for identifying a subre node in debug printouts, so you might think we should get rid of the field entirely; but I have a plan for another use.
* Fix the general case of quantified regex back-references.Tom Lane2012-02-24
| | | | | | | | | | | | | | Cases where a back-reference is part of a larger subexpression that is quantified have never worked in Spencer's regex engine, because he used a compile-time transformation that neglected the need to check the back-reference match in iterations before the last one. (That was okay for capturing parens, and we still do it if the regex has *only* capturing parens ... but it's not okay for backrefs.) To make this work properly, we have to add an "iteration" node type to the regex engine's vocabulary of sub-regex nodes. Since this is a moderately large change with a fair risk of introducing new bugs of its own, apply to HEAD only, even though it's a fix for a longstanding bug.
* Remove arbitrary limitation on length of common name in SSL certificates.Tom Lane2012-02-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Both libpq and the backend would truncate a common name extracted from a certificate at 32 bytes. Replace that fixed-size buffer with dynamically allocated string so that there is no hard limit. While at it, remove the code for extracting peer_dn, which we weren't using for anything; and don't bother to store peer_cn longer than we need it in libpq. This limit was not so terribly unreasonable when the code was written, because we weren't using the result for anything critical, just logging it. But now that there are options for checking the common name against the server host name (in libpq) or using it as the user's name (in the server), this could result in undesirable failures. In the worst case it even seems possible to spoof a server name or user name, if the correct name is exactly 32 bytes and the attacker can persuade a trusted CA to issue a certificate in which that string is a prefix of the certificate's common name. (To exploit this for a server name, he'd also have to send the connection astray via phony DNS data or some such.) The case that this is a realistic security threat is a bit thin, but nonetheless we'll treat it as one. Back-patch to 8.4. Older releases contain the faulty code, but it's not a security problem because the common name wasn't used for anything interesting. Reported and patched by Heikki Linnakangas Security: CVE-2012-0867
* Allow MinGW builds to use standardly-named OpenSSL libraries.Tom Lane2012-02-23
| | | | | | | | In the Fedora variant of MinGW, the openssl libraries have their normal names, not libeay32 and libssleay32. Adjust configure probes to allow that, per bug #6486. Tomasz Ostrowski
* Make EXPLAIN (BUFFERS) track blocks dirtied, as well as those written.Robert Haas2012-02-22
| | | | | | Also expose the new counters through pg_stat_statements. Patch by me. Review by Fujii Masao and Greg Smith.
* Add parameters for controlling locations of server-side SSL filesPeter Eisentraut2012-02-22
| | | | | | | | | | | | This allows changing the location of the files that were previously hard-coded to server.crt, server.key, root.crt, root.crl. server.crt and server.key continue to be the default settings and are thus required to be present by default if SSL is enabled. But the settings for the server-side CA and CRL are now empty by default, and if they are set, the files are required to be present. This replaces the previous behavior of ignoring the functionality if the files were not found.
* REASSIGN OWNED: Support foreign data wrappers and serversAlvaro Herrera2012-02-22
| | | | | | | This was overlooked when implementing those kinds of objects, in commit cae565e503c42a0942ca1771665243b4453c5770. Per report from Pawel Casperek.
* Cosmetic cleanup for commit a760893dbda9934e287789d54bbd3c4ca3914ce0.Tom Lane2012-02-21
| | | | Mostly, fixing overlooked comments.
* Create the beginnings of internals documentation for the regex code.Tom Lane2012-02-19
| | | | | | | | | | Create src/backend/regex/README to hold an implementation overview of the regex package, and fill it in with some preliminary notes about the code's DFA/NFA processing and colormap management. Much more to do there of course. Also, improve some code comments around the colormap and cvec code. No functional changes except to add one missing assert.
* Improve pretty printing of viewdefs.Andrew Dunstan2012-02-19
| | | | | | | | | Some line feeds are added to target lists and from lists to make them more readable. By default they wrap at 80 columns if possible, but the wrap column is also selectable - if 0 it wraps after every item. Andrew Dunstan, reviewed by Hitoshi Harada.
* Improve statistics estimation to make some use of DISTINCT in sub-queries.Tom Lane2012-02-16
| | | | | | | | | | | | | | | | Formerly, we just punted when trying to estimate stats for variables coming out of sub-queries using DISTINCT, on the grounds that whatever stats we might have for underlying table columns would be inapplicable. But if the sub-query has only one DISTINCT column, we can consider its output variable as being unique, which is useful information all by itself. The scope of this improvement is pretty narrow, but it costs nearly nothing, so we might as well do it. Per discussion with Andres Freund. This patch differs from the draft I submitted yesterday in updating various comments about vardata.isunique (to reflect its extended meaning) and in tweaking the interaction with security_barrier views. There does not seem to be a reason why we can't use this sort of knowledge even when the sub-query is such a view.
* Run a portal's cleanup hook immediately when pushing it to FAILED state.Tom Lane2012-02-15
| | | | | | | | | | | | | | | | This extends the changes of commit 6252c4f9e201f619e5eebda12fa867acd4e4200e so that we run the cleanup hook earlier for failure cases as well as success cases. As before, the point is to avoid an assertion failure from an Assert I added in commit a874fe7b4c890d1fe3455215a83ca777867beadd, which was meant to check that no user-written code can be called during portal cleanup. This fixes a case reported by Pavan Deolasee in which the Assert could be triggered during backend exit (see the new regression test case), and also prevents the possibility that the cleanup hook is run after portions of the portal's state have already been recycled. That doesn't really matter in current usage, but it foreseeably could matter in the future. Back-patch to 9.1 where the Assert in question was added.
* Preserve column names in the execution-time tupledesc for a RowExpr.Tom Lane2012-02-14
| | | | | | | | | | | | | | | The hstore and json datatypes both have record-conversion functions that pay attention to column names in the composite values they're handed. We used to not worry about inserting correct field names into tuple descriptors generated at runtime, but given these examples it seems useful to do so. Observe the nicer-looking results in the regression tests whose results changed. catversion bump because there is a subtle change in requirements for stored rule parsetrees: RowExprs from ROW() constructs now have to include field names. Andrew Dunstan and Tom Lane
* Allow LEAKPROOF functions for better performance of security views.Robert Haas2012-02-13
| | | | | | | | | | | | | | | | We don't normally allow quals to be pushed down into a view created with the security_barrier option, but functions without side effects are an exception: they're OK. This allows much better performance in common cases, such as when using an equality operator (that might even be indexable). There is an outstanding issue here with the CREATE FUNCTION / ALTER FUNCTION syntax: there's no way to use ALTER FUNCTION to unset the leakproof flag. But I'm committing this as-is so that it doesn't have to be rebased again; we can fix up the grammar in a future commit. KaiGai Kohei, with some wordsmithing by me.
* Support min/max index optimizations on boolean columns.Tom Lane2012-02-08
| | | | | | | | | | | | Since bool_and() is equivalent to min(), and bool_or() to max(), we might as well let them be index-optimized in the same way. The practical value of this is debatable at best, but it seems nearly cost-free to enable it. Code-wise, we need only adjust the entries in pg_aggregate. There is a measurable planning speed penalty for a query involving one of these aggregates, but it is only a few percent in simple cases, so that seems acceptable. Marti Raudsepp, reviewed by Abhijit Menon-Sen
* Mark some more I/O-conversion-invoking functions as stable not volatile.Tom Lane2012-02-08
| | | | | | | | | | | | | | | | | | | | | When written, textanycat, anytextcat, quote_literal, and quote_nullable were marked volatile, because they could invoke arbitrary type-specific output functions as part of casting their anyelement arguments to text. Since then, we have defined a project policy that I/O functions must not be volatile, as per commit aab353a60b95aadc00f81da0c6d99bde696c4b75. So these functions can safely be downgraded to stable. Most of the time this makes no difference since they'll get inlined anyway, but as noted by Andrew Dunstan, there are cases where the volatile marking prevents optimizations that the planner does before function inlining. (I think I might have overlooked these functions in the earlier commit on the grounds that inlining would make it moot, but not so --- tgl) This change results in a change in the expected output of the json regression tests, because the planner can now flatten a sub-select that it failed to before. The old output is preferable, but getting that back will require some as-yet-unfinished work on RowExpr handling. Marti Raudsepp
* Add transform functions for various temporal typmod coercisions.Robert Haas2012-02-08
| | | | | | This enables ALTER TABLE to skip table and index rebuilds in some cases. Noah Misch, with trivial changes by me.
* Rename LWLockWaitUntilFree to LWLockAcquireOrWait.Heikki Linnakangas2012-02-08
| | | | | LWLockAcquireOrWait makes it more clear that the lock is acquired if it's free.