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path: root/src/backend/access/gin/ginbtree.c
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* Fix locking when fixing an incomplete split of a GIN internal pageHeikki Linnakangas2024-01-29
| | | | | | | | | | | | | | | | | ginFinishSplit() expects the caller to hold an exclusive lock on the buffer, but when finishing an earlier "leftover" incomplete split of an internal page, the caller held a shared lock. That caused an assertion failure in MarkBufferDirty(). Without assertions, it could lead to corruption if two backends tried to complete the split at the same time. On master, add a test case using the new injection point facility. Report and analysis by Fei Changhong. Backpatch the fix to all supported versions. Reviewed-by: Fei Changhong, Michael Paquier Discussion: https://www.postgresql.org/message-id/tencent_A3CE810F59132D8E230475A5F0F7A08C8307@qq.com
* Don't release index root page pin in ginFindParents().Tom Lane2023-11-13
| | | | | | | | | | | | | | | | | | | | | It's clearly stated in the comments that ginFindParents() must keep the pin on the index's root page that's associated with the topmost GinBtreeStack item. However, the code path for the case that the desired downlink has been pushed down to the next index level ignored this proviso, and would release the pin anyway if we were still examining the root level. That led to an assertion failure or "buffer NNNN is not owned by resource owner" error later, when we try to release the pin again at the end of the insertion. This is quite hard to reproduce, since it can only happen if an index root page split occurs concurrently with our own insertion. Thanks to Jeff Janes for finding a test case that triggers it often enough to allow investigation. This has been there since the beginning of GIN, so back-patch to all supported branches. Discussion: https://postgr.es/m/CAMkU=1yCAKtv86dMrD__Ja-7KzjE=uMeKX8y__cx5W-OEWy2ow@mail.gmail.com
* Fix traversing to the deleted GIN page via downlinkAlexander Korotkov2019-11-20
| | | | | | | | | | | | | | | Current GIN code appears to don't handle traversing to the deleted page via downlink. This commit fixes that by stepping right from the delete page like we do in nbtree. This commit also fixes setting 'deleted' flag to the GIN pages. Now other page flags are not erased once page is deleted. That helps to keep our assertions true if we arrive deleted page via downlink. Discussion: https://postgr.es/m/CAPpHfdvMvsw-NcE5bRS7R1BbvA4BxoDnVVjkXC5W0Czvy9LVrg%40mail.gmail.com Author: Alexander Korotkov Reviewed-by: Peter Geoghegan Backpatch-through: 9.4
* 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
* Generate less WAL during GiST, GIN and SP-GiST index build.Heikki Linnakangas2019-04-03
| | | | | | | | | | | | | | | | | | | | Instead of WAL-logging every modification during the build separately, first build the index without any WAL-logging, and make a separate pass through the index at the end, to write all pages to the WAL. This significantly reduces the amount of WAL generated, and is usually also faster, despite the extra I/O needed for the extra scan through the index. WAL generated this way is also faster to replay. For GiST, the LSN-NSN interlock makes this a little tricky. All pages must be marked with a valid (i.e. non-zero) LSN, so that the parent-child LSN-NSN interlock works correctly. We now use magic value 1 for that during index build. Change the fake LSN counter to begin from 1000, so that 1 is safely smaller than any real or fake LSN. 2 would've been enough for our purposes, but let's reserve a bigger range, in case we need more special values in the future. Author: Anastasia Lubennikova, Andrey V. Lepikhov Reviewed-by: Heikki Linnakangas, Dmitry Dolgov
* Update copyright for 2019Bruce Momjian2019-01-02
| | | | Backpatch-through: certain files through 9.4
* Remove entry tree root conflict checking from GIN predicate lockingAlexander Korotkov2018-12-27
| | | | | | | | | | | | | | According to README we acquire predicate locks on entry tree leafs and posting tree roots. However, when ginFindLeafPage() is going to lock leaf in exclusive mode, then it checks root for conflicts regardless whether it's a entry or posting tree. Assuming that we never place predicate lock on entry tree root (excluding corner case when root is leaf), this check is redundant. This commit removes this check. Now, root conflict checking is controlled by separate argument of ginFindLeafPage(). Discussion: https://postgr.es/m/CAPpHfdv7rrDyy%3DMgsaK-L9kk0AH7az0B-mdC3w3p0FSb9uoyEg%40mail.gmail.com Author: Alexander Korotkov Backpatch-through: 11
* Remove duplicated words split across lines in commentsMichael Paquier2018-09-08
| | | | | | | | This has been detected using some interesting tricks with sed, and the method used is mentioned in details in the discussion below. Author: Justin Pryzby Discussion: https://postgr.es/m/20180908013109.GB15350@telsasoft.com
* Re-think predicate locking on GIN indexes.Teodor Sigaev2018-05-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The principle behind the locking was not very well thought-out, and not documented. Add a section in the README to explain how it's supposed to work, and change the code so that it actually works that way. This fixes two bugs: 1. If fast update was turned on concurrently, subsequent inserts to the pending list would not conflict with predicate locks that were acquired earlier, on entry pages. The included 'predicate-gin-fastupdate' test demonstrates that. To fix, make all scans acquire a predicate lock on the metapage. That lock represents a scan of the pending list, whether or not there is a pending list at the moment. Forget about the optimization to skip locking/checking for locks, when fastupdate=off. 2. If a scan finds no match, it still needs to lock the entry page. The point of predicate locks is to lock the gabs between values, whether or not there is a match. The included 'predicate-gin-nomatch' test tests that case. In addition to those two bug fixes, this removes some unnecessary locking, following the principle laid out in the README. Because all items in a posting tree have the same key value, a lock on the posting tree root is enough to cover all the items. (With a very large posting tree, it would possibly be better to lock the posting tree leaf pages instead, so that a "skip scan" with a query like "A & B", you could avoid unnecessary conflict if a new tuple is inserted with A but !B. But let's keep this simple.) Also, some spelling fixes. Author: Heikki Linnakangas with some editorization by me Review: Andrey Borodin, Alexander Korotkov Discussion: https://www.postgresql.org/message-id/0b3ad2c2-2692-62a9-3a04-5724f2af9114@iki.fi
* Post-feature-freeze pgindent run.Tom Lane2018-04-26
| | | | Discussion: https://postgr.es/m/15719.1523984266@sss.pgh.pa.us
* Predicate locking in GIN indexTeodor Sigaev2018-03-30
| | | | | | | | | | | Predicate locks are used on per page basis only if fastupdate = off, in opposite case predicate lock on pending list will effectively lock whole index, to reduce locking overhead, just lock a relation. Entry and posting trees are essentially B-tree, so locks are acquired on leaf pages only. Author: Shubham Barai with some editorization by me and Dmitry Ivanov Review by: Alexander Korotkov, Dmitry Ivanov, Fedor Sigaev Discussion: https://www.postgresql.org/message-id/flat/CALxAEPt5sWW+EwTaKUGFL5_XFcZ0MuGBcyJ70oqbWqr42YKR8Q@mail.gmail.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>
* Reduce page locking in GIN vacuumTeodor Sigaev2017-03-23
| | | | | | | | | | | | | GIN vacuum during cleaning posting tree can lock this whole tree for a long time with by holding LockBufferForCleanup() on root. Patch changes it with two ways: first, cleanup lock will be taken only if there is an empty page (which should be deleted) and, second, it tries to lock only subtree, not the whole posting tree. Author: Andrey Borodin with minor editorization by me Reviewed-by: Jeff Davis, me https://commitfest.postgresql.org/13/896/
* Split index xlog headers from other private index headers.Robert Haas2017-02-14
| | | | | | | | | | | | | The xlog-specific headers need to be included in both frontend code - specifically, pg_waldump - and the backend, but the remainder of the private headers for each index are only needed by the backend. By splitting the xlog stuff out into separate headers, pg_waldump pulls in fewer backend headers, which is a good thing. Patch by me, reviewed by Michael Paquier and Andres Freund, per a complaint from Dilip Kumar. Discussion: http://postgr.es/m/CA+TgmoZ=F=GkxV0YEv-A8tb+AEGy_Qa7GSiJ8deBKFATnzfEug@mail.gmail.com
* Update copyright via script for 2017Bruce Momjian2017-01-03
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* Add macros to make AllocSetContextCreate() calls simpler and safer.Tom Lane2016-08-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I found that half a dozen (nearly 5%) of our AllocSetContextCreate calls had typos in the context-sizing parameters. While none of these led to especially significant problems, they did create minor inefficiencies, and it's now clear that expecting people to copy-and-paste those calls accurately is not a great idea. Let's reduce the risk of future errors by introducing single macros that encapsulate the common use-cases. Three such macros are enough to cover all but two special-purpose contexts; those two calls can be left as-is, I think. While this patch doesn't in itself improve matters for third-party extensions, it doesn't break anything for them either, and they can gradually adopt the simplified notation over time. In passing, change TopMemoryContext to use the default allocation parameters. Formerly it could only be extended 8K at a time. That was probably reasonable when this code was written; but nowadays we create many more contexts than we did then, so that it's not unusual to have a couple hundred K in TopMemoryContext, even without considering various dubious code that sticks other things there. There seems no good reason not to let it use growing blocks like most other contexts. Back-patch to 9.6, mostly because that's still close enough to HEAD that it's easy to do so, and keeping the branches in sync can be expected to avoid some future back-patching pain. The bugs fixed by these changes don't seem to be significant enough to justify fixing them further back. Discussion: <21072.1472321324@sss.pgh.pa.us>
* Fix memory leak and other bugs in ginPlaceToPage() & subroutines.Tom Lane2016-04-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 36a35c550ac114ca turned the interface between ginPlaceToPage and its subroutines in gindatapage.c and ginentrypage.c into a royal mess: page-update critical sections were started in one place and finished in another place not even in the same file, and the very same subroutine might return having started a critical section or not. Subsequent patches band-aided over some of the problems with this design by making things even messier. One user-visible resulting problem is memory leaks caused by the need for the subroutines to allocate storage that would survive until ginPlaceToPage calls XLogInsert (as reported by Julien Rouhaud). This would not typically be noticeable during retail index updates. It could be visible in a GIN index build, in the form of memory consumption swelling to several times the commanded maintenance_work_mem. Another rather nasty problem is that in the internal-page-splitting code path, we would clear the child page's GIN_INCOMPLETE_SPLIT flag well before entering the critical section that it's supposed to be cleared in; a failure in between would leave the index in a corrupt state. There were also assorted coding-rule violations with little immediate consequence but possible long-term hazards, such as beginning an XLogInsert sequence before entering a critical section, or calling elog(DEBUG) inside a critical section. To fix, redefine the API between ginPlaceToPage() and its subroutines by splitting the subroutines into two parts. The "beginPlaceToPage" subroutine does what can be done outside a critical section, including full computation of the result pages into temporary storage when we're going to split the target page. The "execPlaceToPage" subroutine is called within a critical section established by ginPlaceToPage(), and it handles the actual page update in the non-split code path. The critical section, as well as the XLOG insertion call sequence, are both now always started and finished in ginPlaceToPage(). Also, make ginPlaceToPage() create and work in a short-lived memory context to eliminate the leakage problem. (Since a short-lived memory context had been getting created in the most common code path in the subroutines, this shouldn't cause any noticeable performance penalty; we're just moving the overhead up one call level.) In passing, fix a bunch of comments that had gone unmaintained throughout all this klugery. Report: <571276DD.5050303@dalibo.com>
* Revert no-op changes to BufferGetPage()Kevin Grittner2016-04-20
| | | | | | | | | | | | | | | | | | The reverted changes were intended to force a choice of whether any newly-added BufferGetPage() calls needed to be accompanied by a test of the snapshot age, to support the "snapshot too old" feature. Such an accompanying test is needed in about 7% of the cases, where the page is being used as part of a scan rather than positioning for other purposes (such as DML or vacuuming). The additional effort required for back-patching, and the doubt whether the intended benefit would really be there, have indicated it is best just to rely on developers to do the right thing based on comments and existing usage, as we do with many other conventions. This change should have little or no effect on generated executable code. Motivated by the back-patching pain of Tom Lane and Robert Haas
* Add the "snapshot too old" featureKevin Grittner2016-04-08
| | | | | | | | | | | | | | | | This feature is controlled by a new old_snapshot_threshold GUC. A value of -1 disables the feature, and that is the default. The value of 0 is just intended for testing. Above that it is the number of minutes a snapshot can reach before pruning and vacuum are allowed to remove dead tuples which the snapshot would otherwise protect. The xmin associated with a transaction ID does still protect dead tuples. A connection which is using an "old" snapshot does not get an error unless it accesses a page modified recently enough that it might not be able to produce accurate results. This is similar to the Oracle feature, and we use the same SQLSTATE and error message for compatibility.
* Modify BufferGetPage() to prepare for "snapshot too old" featureKevin Grittner2016-04-08
| | | | | | | | | | | This patch is a no-op patch which is intended to reduce the chances of failures of omission once the functional part of the "snapshot too old" patch goes in. It adds parameters for snapshot, relation, and an enum to specify whether the snapshot age check needs to be done for the page at this point. This initial patch passes NULL for the first two new parameters and BGP_NO_SNAPSHOT_TEST for the third. The follow-on patch will change the places where the test needs to be made.
* Update copyright for 2016Bruce Momjian2016-01-02
| | | | Backpatch certain files through 9.1
* Fix double-XLogBeginInsert call in GIN page splits.Heikki Linnakangas2015-06-28
| | | | | | | | | | | | | | If data checksums or wal_log_hints is on, and a GIN page is split, the code to find a new, empty, block was called after having already called XLogBeginInsert(). That causes an assertion failure or PANIC, if finding the new block involves updating a FSM page that had not been modified since last checkpoint, because that update is WAL-logged, which calls XLogBeginInsert again. Nested XLogBeginInsert calls are not supported. To fix, rearrange GIN code so that XLogBeginInsert is called later, after finding the victim buffers. Reported by Jeff Janes.
* 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.
* Update copyright for 2015Bruce Momjian2015-01-06
| | | | Backpatch certain files through 9.0
* Revamp the WAL record format.Heikki Linnakangas2014-11-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Each WAL record now carries information about the modified relation and block(s) in a standardized format. That makes it easier to write tools that need that information, like pg_rewind, prefetching the blocks to speed up recovery, etc. There's a whole new API for building WAL records, replacing the XLogRecData chains used previously. The new API consists of XLogRegister* functions, which are called for each buffer and chunk of data that is added to the record. The new API also gives more control over when a full-page image is written, by passing flags to the XLogRegisterBuffer function. This also simplifies the XLogReadBufferForRedo() calls. The function can dig the relation and block number from the WAL record, so they no longer need to be passed as arguments. For the convenience of redo routines, XLogReader now disects each WAL record after reading it, copying the main data part and the per-block data into MAXALIGNed buffers. The data chunks are not aligned within the WAL record, but the redo routines can assume that the pointers returned by XLogRecGet* functions are. Redo routines are now passed the XLogReaderState, which contains the record in the already-disected format, instead of the plain XLogRecord. The new record format also makes the fixed size XLogRecord header smaller, by removing the xl_len field. The length of the "main data" portion is now stored at the end of the WAL record, and there's a separate header after XLogRecord for it. The alignment padding at the end of XLogRecord is also removed. This compansates for the fact that the new format would otherwise be more bulky than the old format. Reviewed by Andres Freund, Amit Kapila, Michael Paquier, Alvaro Herrera, Fujii Masao.
* Move the backup-block logic from XLogInsert to a new file, xloginsert.c.Heikki Linnakangas2014-11-06
| | | | | | | | | | | | xlog.c is huge, this makes it a little bit smaller, which is nice. Functions related to putting together the WAL record are in xloginsert.c, and the lower level stuff for managing WAL buffers and such are in xlog.c. Also move the definition of XLogRecord to a separate header file. This causes churn in the #includes of all the files that write WAL records, and redo routines, but it avoids pulling in xlog.h into most places. Reviewed by Michael Paquier, Alvaro Herrera, Andres Freund and Amit Kapila.
* pgindent run for 9.4Bruce Momjian2014-05-06
| | | | | This includes removing tabs after periods in C comments, which was applied to back branches, so this change should not effect backpatching.
* Fix bug in the new GIN incomplete-split code.Heikki Linnakangas2014-04-01
| | | | | | | | Inserting a downlink to an internal page clears the incomplete-split flag of the child's left sibling, so the left sibling's LSN also needs to be updated and it needs to be marked dirty. The codepath for an insertion got this right, but the case where the internal node is split because of inserting the new downlink missed that.
* Silence compiler warning.Heikki Linnakangas2014-01-23
| | | | Not all compilers understand that elog(ERROR, ...) never returns.
* Compress GIN posting lists, for smaller index size.Heikki Linnakangas2014-01-22
| | | | | | | | | | | | | | | | | | | | | GIN posting lists are now encoded using varbyte-encoding, which allows them to fit in much smaller space than the straight ItemPointer array format used before. The new encoding is used for both the lists stored in-line in entry tree items, and in posting tree leaf pages. To maintain backwards-compatibility and keep pg_upgrade working, the code can still read old-style pages and tuples. Posting tree leaf pages in the new format are flagged with GIN_COMPRESSED flag, to distinguish old and new format pages. Likewise, entry tree tuples in the new format have a GIN_ITUP_COMPRESSED flag set in a bit that was previously unused. This patch bumps GIN_CURRENT_VERSION from 1 to 2. New indexes created with version 9.4 will therefore have version number 2 in the metapage, while old pg_upgraded indexes will have version 1. The code treats them the same, but it might be come handy in the future, if we want to drop support for the uncompressed format. Alexander Korotkov and me. Reviewed by Tomas Vondra and Amit Langote.
* Update copyright for 2014Bruce Momjian2014-01-07
| | | | | Update all files in head, and files COPYRIGHT and legal.sgml in all back branches.
* Get rid of the post-recovery cleanup step of GIN page splits.Heikki Linnakangas2013-11-27
| | | | | | | | | | | | | | | | | | Replace it with an approach similar to what GiST uses: when a page is split, the left sibling is marked with a flag indicating that the parent hasn't been updated yet. When the parent is updated, the flag is cleared. If an insertion steps on a page with the flag set, it will finish split before proceeding with the insertion. The post-recovery cleanup mechanism was never totally reliable, as insertion to the parent could fail e.g because of running out of memory or disk space, leaving the tree in an inconsistent state. This also divides the responsibility of WAL-logging more clearly between the generic ginbtree.c code, and the parts specific to entry and posting trees. There is now a common WAL record format for insertions and deletions, which is written by ginbtree.c, followed by tree-specific payload, which is returned by the placetopage- and split- callbacks.
* More GIN refactoring.Heikki Linnakangas2013-11-27
| | | | | | | | | | | | Separate the insertion payload from the more static portions of GinBtree. GinBtree now only contains information related to searching the tree, and the information of what to insert is passed separately. Add root block number to GinBtree, instead of passing it around all the functions as argument. Split off ginFinishSplit() from ginInsertValue(). ginFinishSplit is responsible for finding the parent and inserting the downlink to it.
* More GIN refactoring.Heikki Linnakangas2013-11-20
| | | | | | | | | | | Split off the portion of ginInsertValue that inserts the tuple to current level into a separate function, ginPlaceToPage. ginInsertValue's charter is now to recurse up the tree to insert the downlink, when a page split is required. This is in preparation for a patch to change the way incomplete splits are handled, which will need to do these operations separately. And IMHO makes the code more readable anyway.
* Refactor the internal GIN B-tree interface for forming a downlink.Heikki Linnakangas2013-11-20
| | | | | | This creates a new gin-btree callback function for creating a downlink for a page. Previously, ginxlog.c duplicated the logic used during normal operation.
* Further GIN refactoring.Heikki Linnakangas2013-11-20
| | | | | Merge some functions that were always called together. Makes the code little bit more readable.
* Fix race condition in GIN posting tree page deletion.Heikki Linnakangas2013-11-08
| | | | | | | | | | | | | | | | | | If a page is deleted, and reused for something else, just as a search is following a rightlink to it from its left sibling, the search would continue scanning whatever the new contents of the page are. That could lead to incorrect query results, or even something more curious if the page is reused for a different kind of a page. To fix, modify the search algorithm to lock the next page before releasing the previous one, and refrain from deleting pages from the leftmost branch of the tree. Add a new Concurrency section to the README, explaining why this works. There is a lot more one could say about concurrency in GIN, but that's for another patch. Backpatch to all supported versions.
* Misc GIN refactoring.Heikki Linnakangas2013-11-06
| | | | | | | | | | | | | | | Merge the isEnoughSpace and placeToPage functions in the b-tree interface into one function that tries to put a tuple on page, and returns false if it doesn't fit. Move createPostingTree function to gindatapage.c, and change its contract so that it can be passed more items than fit on the root page. It's in a better position than the callers to know how many items fit. Move ginMergeItemPointers out of gindatapage.c, into a separate file. These changes make no difference now, but reduce the footprint of Alexander Korotkov's upcoming patch to pack item pointers more tightly.
* pgindent run for release 9.3Bruce Momjian2013-05-29
| | | | | This is the first run of the Perl-based pgindent script. Also update pgindent instructions.
* Remove PageSetTLI and rename pd_tli to pd_checksumSimon Riggs2013-03-18
| | | | | | | | | | | | | | Remove use of PageSetTLI() from all page manipulation functions and adjust README to indicate change in the way we make changes to pages. Repurpose those bytes into the pd_checksum field and explain how that works in comments about page header. Refactoring ahead of actual feature patch which would make use of the checksum field, arriving later. Jeff Davis, with comments and doc changes by Simon Riggs Direction suggested by Robert Haas; many others providing review comments.
* Update copyrights for 2013Bruce Momjian2013-01-01
| | | | | Fully update git head, and update back branches in ./COPYRIGHT and legal.sgml files.
* Remove unreachable codePeter Eisentraut2012-07-16
| | | | | | | The Solaris Studio compiler warns about these instances, unlike more mainstream compilers such as gcc. But manual inspection showed that the code is clearly not reachable, and we hope no worthy compiler will complain about removing this code.
* Cosmetic cleanup of ginInsertValue().Tom Lane2012-07-13
| | | | | | | | Make it clearer that the passed stack mustn't be empty, and that we are not supposed to fall off the end of the stack in the main loop. Tighten the loop that extracts the root block number, too. Markus Wanner and Tom Lane
* Update copyright notices for year 2012.Bruce Momjian2012-01-01
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* Remove unnecessary #include references, per pgrminclude script.Bruce Momjian2011-09-01
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* Fix GIN to support null keys, empty and null items, and full index scans.Tom Lane2011-01-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Per my recent proposal(s). Null key datums can now be returned by extractValue and extractQuery functions, and will be stored in the index. Also, placeholder entries are made for indexable items that are NULL or contain no keys according to extractValue. This means that the index is now always complete, having at least one entry for every indexed heap TID, and so we can get rid of the prohibition on full-index scans. A full-index scan is implemented much the same way as partial-match scans were already: we build a bitmap representing all the TIDs found in the index, and then drive the results off that. Also, introduce a concept of a "search mode" that can be requested by extractQuery when the operator requires matching to empty items (this is just as cheap as matching to a single key) or requires a full index scan (which is not so cheap, but it sure beats failing or giving wrong answers). The behavior remains backward compatible for opclasses that don't return any null keys or request a non-default search mode. Using these features, we can now make the GIN index opclass for anyarray behave in a way that matches the actual anyarray operators for &&, <@, @>, and = ... which it failed to do before in assorted corner cases. This commit fixes the core GIN code and ginarrayprocs.c, updates the documentation, and adds some simple regression test cases for the new behaviors using the array operators. The tsearch and contrib GIN opclass support functions still need to be looked over and probably fixed. Another thing I intend to fix separately is that this is pretty inefficient for cases where more than one scan condition needs a full-index search: we'll run duplicate GinScanEntrys, each one of which builds a large bitmap. There is some existing logic to merge duplicate GinScanEntrys but it needs refactoring to make it work for entries belonging to different scan keys. Note that most of gin.h has been split out into a new file gin_private.h, so that gin.h doesn't export anything that's not supposed to be used by GIN opclasses or the rest of the backend. I did quite a bit of other code beautification work as well, mostly fixing comments and choosing more appropriate names for things.
* Stamp copyrights for year 2011.Bruce Momjian2011-01-01
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* Generalize concept of temporary relations to "relation persistence".Robert Haas2010-12-13
| | | | | | | | | | | | | | | 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.
* Fix a passel of inappropriately-named global functions in GIN.Tom Lane2010-10-17
| | | | | | | | | | | | | | | | The GIN code has absolutely no business exporting GIN-specific functions with names as generic as compareItemPointers() or newScanKey(); that's just trouble waiting to happen. I got annoyed about this again just now and decided to fix it. This commit ensures that all global symbols defined in access/gin/ have names including "gin" or "Gin". There were a couple of cases, like names involving "PostingItem", where arguably the names were already sufficiently nongeneric; but I figured as long as I was risking creating merge problems for unapplied GIN patches I might as well impose a uniform policy. I didn't touch any static symbol names. There might be some places where it'd be appropriate to rename some static functions to match siblings that are exported, but I'll leave that for another time.
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