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* Remove unnecessary (char *) casts [xlog]Peter Eisentraut2025-02-13
| | | | | | | | Remove (char *) casts no longer needed after XLogRegisterData() and XLogRegisterBufData() argument type change. Reviewed-by: Dagfinn Ilmari Mannsåker <ilmari@ilmari.org> Discussion: https://www.postgresql.org/message-id/flat/fd1fcedb-3492-4fc8-9e3e-74b97f2db6c7%40eisentraut.org
* Update copyright for 2025Bruce Momjian2025-01-01
| | | | Backpatch-through: 13
* Remove unused #include's from backend .c filesPeter Eisentraut2024-03-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | as determined by include-what-you-use (IWYU) While IWYU also suggests to *add* a bunch of #include's (which is its main purpose), this patch does not do that. In some cases, a more specific #include replaces another less specific one. Some manual adjustments of the automatic result: - IWYU currently doesn't know about includes that provide global variable declarations (like -Wmissing-variable-declarations), so those includes are being kept manually. - All includes for port(ability) headers are being kept for now, to play it safe. - No changes of catalog/pg_foo.h to catalog/pg_foo_d.h, to keep the patch from exploding in size. Note that this patch touches just *.c files, so nothing declared in header files changes in hidden ways. As a small example, in src/backend/access/transam/rmgr.c, some IWYU pragma annotations are added to handle a special case there. Discussion: https://www.postgresql.org/message-id/flat/af837490-6b2f-46df-ba05-37ea6a6653fc%40eisentraut.org
* Update copyright for 2024Bruce Momjian2024-01-03
| | | | | | | | Reported-by: Michael Paquier Discussion: https://postgr.es/m/ZZKTDPxBBMt3C0J9@paquier.xyz Backpatch-through: 12
* Assert that buffers are marked dirty before XLogRegisterBuffer().Jeff Davis2023-10-23
| | | | | | | | | | | Enforce the rule from transam/README in XLogRegisterBuffer(), and update callers to follow the rule. Hash indexes sometimes register clean pages as a part of the locking protocol, so provide a REGBUF_NO_CHANGE flag to support that use. Discussion: https://postgr.es/m/c84114f8-c7f1-5b57-f85a-3adc31e1a904@iki.fi Reviewed-by: Heikki Linnakangas
* Update copyright for 2023Bruce Momjian2023-01-02
| | | | Backpatch-through: 11
* Update copyright for 2022Bruce Momjian2022-01-07
| | | | Backpatch-through: 10
* Update copyright for 2021Bruce Momjian2021-01-02
| | | | Backpatch-through: 9.5
* Update copyrights for 2020Bruce Momjian2020-01-01
| | | | Backpatch-through: update all files in master, backpatch legal files 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
* Avoid using potentially-under-aligned page buffers.Tom Lane2018-09-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | There's a project policy against using plain "char buf[BLCKSZ]" local or static variables as page buffers; preferred style is to palloc or malloc each buffer to ensure it is MAXALIGN'd. However, that policy's been ignored in an increasing number of places. We've apparently got away with it so far, probably because (a) relatively few people use platforms on which misalignment causes core dumps and/or (b) the variables chance to be sufficiently aligned anyway. But this is not something to rely on. Moreover, even if we don't get a core dump, we might be paying a lot of cycles for misaligned accesses. To fix, invent new union types PGAlignedBlock and PGAlignedXLogBlock that the compiler must allocate with sufficient alignment, and use those in place of plain char arrays. I used these types even for variables where there's no risk of a misaligned access, since ensuring proper alignment should make kernel data transfers faster. I also changed some places where we had been palloc'ing short-lived buffers, for coding style uniformity and to save palloc/pfree overhead. Since this seems to be a live portability hazard (despite the lack of field reports), back-patch to all supported versions. Patch by me; thanks to Michael Paquier for review. Discussion: https://postgr.es/m/1535618100.1286.3.camel@credativ.de
* 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>
* Phase 3 of pgindent updates.Tom Lane2017-06-21
| | | | | | | | | | | | | | | | | | | | | | | | | Don't move parenthesized lines to the left, even if that means they flow past the right margin. By default, BSD indent lines up statement continuation lines that are within parentheses so that they start just to the right of the preceding left parenthesis. However, traditionally, if that resulted in the continuation line extending to the right of the desired right margin, then indent would push it left just far enough to not overrun the margin, if it could do so without making the continuation line start to the left of the current statement indent. That makes for a weird mix of indentations unless one has been completely rigid about never violating the 80-column limit. This behavior has been pretty universally panned by Postgres developers. Hence, disable it with indent's new -lpl switch, so that parenthesized lines are always lined up with the preceding left paren. This patch is much less interesting than the first round of indent changes, but also bulkier, so I thought it best to separate the effects. Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
* 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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* 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
* 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.
* 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.
* GIN entry pages follow the standard page layout - tell XLogInsert.Heikki Linnakangas2014-04-14
| | | | | | The entry B-tree pages all follow the standard page layout. The 9.3 code has this right. I inadvertently changed this at some point during the big refactorings in git master.
* Allow use of "z" flag in our printf calls, and use it where appropriate.Tom Lane2014-01-23
| | | | | | | | | | | | | | | | | | | | | | | | | Since C99, it's been standard for printf and friends to accept a "z" size modifier, meaning "whatever size size_t has". Up to now we've generally dealt with printing size_t values by explicitly casting them to unsigned long and using the "l" modifier; but this is really the wrong thing on platforms where pointers are wider than longs (such as Win64). So let's start using "z" instead. To ensure we can do that on all platforms, teach src/port/snprintf.c to understand "z", and add a configure test to force use of that implementation when the platform's version doesn't handle "z". Having done that, modify a bunch of places that were using the unsigned-long hack to use "z" instead. This patch doesn't pretend to have gotten everyplace that could benefit, but it catches many of them. I made an effort in particular to ensure that all uses of the same error message text were updated together, so as not to increase the number of translatable strings. It's possible that this change will result in format-string warnings from pre-C99 compilers. We might have to reconsider if there are any popular compilers that will warn about this; but let's start by seeing what the buildfarm thinks. Andres Freund, with a little additional work by me
* Fix alignment of GIN in-line posting lists stored in entry tuples.Heikki Linnakangas2014-01-23
| | | | | | | | | | | | The Sparc machines in the buildfarm are crashing because of misaligned access to posting lists stored in entry tuples. I accidentally removed a critical SHORTALIGN() from ginFormTuple, as part of the packed posting lists patch. Perhaps I thought it was unnecessary, because the index_form_tuple() call above the SHORTALIGN already aligned the size, missing the fact that the null-category byte makes it misaligned again (I think the SHORTALIGN is indeed unnecessary if there's no null- category byte, but let's just play it safe...)
* 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.
* Fix full-page writes of internal GIN pages.Heikki Linnakangas2013-12-03
| | | | | | | | | | | | | | | Insertion to a non-leaf GIN page didn't make a full-page image of the page, which is wrong. The code used to do it correctly, but was changed (commit 853d1c3103fa961ae6219f0281885b345593d101) because the redo-routine didn't track incomplete splits correctly when the page was restored from a full page image. Of course, that was not right way to fix it, the redo routine should've been fixed instead. The redo-routine was surreptitiously fixed in 2010 (commit 4016bdef8aded77b4903c457050622a5a1815c16), so all we need to do now is revert the code that creates the record to its original form. This doesn't change the format of the WAL record. Backpatch to all supported versions.
* 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.
* 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.
* 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.
* Initialize pad bytes in GinFormTuple().Noah Misch2013-06-26
| | | | | | | Every other core buffer page consumer initializes the bytes it furnishes to PageAddItem(). For consistency, do the same here. No back-patch; regardless, we couldn't count on the fix so long as binary upgrade can carry forward affected index builds.
* Update copyrights for 2013Bruce Momjian2013-01-01
| | | | | Fully update git head, and update back branches in ./COPYRIGHT and legal.sgml files.
* Lots of doc corrections.Robert Haas2012-04-23
| | | | Josh Kupershmidt
* 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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* pgindent run before PG 9.1 beta 1.Bruce Momjian2011-04-10
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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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* 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.
* Improve GIN indexscan cost estimation.Tom Lane2010-10-17
| | | | | | | | | | | | | The better estimate requires more statistics than we previously stored: in particular, counts of "entry" versus "data" pages within the index, as well as knowledge of the number of distinct key values. We collect this information during initial index build and update it during VACUUM, storing the info in new fields on the index metapage. No initdb is required because these fields will read as zeroes in a pre-existing index, and the new gincostestimate code is coded to behave (reasonably) sanely if they are zeroes. Teodor Sigaev, reviewed by Jan Urbanski, Tom Lane, and Itagaki Takahiro.
* Remove cvs keywords from all files.Magnus Hagander2010-09-20
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* Rewrite the rbtree routines so that an RBNode is the first field of theTom Lane2010-08-01
| | | | | | | | | | | | | | | | | | | | struct representing a tree entry, rather than being a separately allocated piece of storage. This API is at least as clean as the old one (if not more so --- there were some bizarre choices in there) and it permits a very substantial memory savings, on the order of 2X in ginbulk.c's usage. Also, fix minor memory leaks in code called by ginEntryInsert, in particular in ginInsertValue and entryFillRoot, as well as ginEntryInsert itself. These leaks resulted in the GIN index build context continuing to bloat even after we'd filled it to maintenance_work_mem and started to dump data out to the index. In combination these fixes restore the GIN index build code to honoring the maintenance_work_mem limit about as well as it did in 8.4. Speed seems on par with 8.4 too, maybe even a bit faster, for a non-pathological case in which HEAD was formerly slower. Back-patch to 9.0 so we don't have a performance regression from 8.4.