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2020-06-16Fix buffile.c error handling.Thomas Munro
Convert buffile.c error handling to use ereport. This fixes cases where I/O errors were indistinguishable from EOF or not reported. Also remove "%m" from error messages where errno would be bogus. While we're modifying those strings, add block numbers and short read byte counts where appropriate. Back-patch to all supported releases. Reported-by: Amit Khandekar <amitdkhan.pg@gmail.com> Reviewed-by: Melanie Plageman <melanieplageman@gmail.com> Reviewed-by: Alvaro Herrera <alvherre@2ndquadrant.com> Reviewed-by: Robert Haas <robertmhaas@gmail.com> Reviewed-by: Ibrar Ahmed <ibrar.ahmad@gmail.com> Reviewed-by: Michael Paquier <michael@paquier.xyz> Discussion: https://postgr.es/m/CA%2BhUKGJE04G%3D8TLK0DLypT_27D9dR8F1RQgNp0jK6qR0tZGWOw%40mail.gmail.com
2020-03-22Revert "Skip WAL for new relfilenodes, under wal_level=minimal."Noah Misch
This reverts commit cb2fd7eac285b1b0a24eeb2b8ed4456b66c5a09f. Per numerous buildfarm members, it was incompatible with parallel query, and a test case assumed LP64. Back-patch to 9.5 (all supported versions). Discussion: https://postgr.es/m/20200321224920.GB1763544@rfd.leadboat.com
2020-03-21Skip WAL for new relfilenodes, under wal_level=minimal.Noah Misch
Until now, only selected bulk operations (e.g. COPY) did this. If a given relfilenode received both a WAL-skipping COPY and a WAL-logged operation (e.g. INSERT), recovery could lose tuples from the COPY. See src/backend/access/transam/README section "Skipping WAL for New RelFileNode" for the new coding rules. Maintainers of table access methods should examine that section. To maintain data durability, just before commit, we choose between an fsync of the relfilenode and copying its contents to WAL. A new GUC, wal_skip_threshold, guides that choice. If this change slows a workload that creates small, permanent relfilenodes under wal_level=minimal, try adjusting wal_skip_threshold. Users setting a timeout on COMMIT may need to adjust that timeout, and log_min_duration_statement analysis will reflect time consumption moving to COMMIT from commands like COPY. Internally, this requires a reliable determination of whether RollbackAndReleaseCurrentSubTransaction() would unlink a relation's current relfilenode. Introduce rd_firstRelfilenodeSubid. Amend the specification of rd_createSubid such that the field is zero when a new rel has an old rd_node. Make relcache.c retain entries for certain dropped relations until end of transaction. Back-patch to 9.5 (all supported versions). This introduces a new WAL record type, XLOG_GIST_ASSIGN_LSN, without bumping XLOG_PAGE_MAGIC. As always, update standby systems before master systems. This changes sizeof(RelationData) and sizeof(IndexStmt), breaking binary compatibility for affected extensions. (The most recent commit to affect the same class of extensions was 089e4d405d0f3b94c74a2c6a54357a84a681754b.) Kyotaro Horiguchi, reviewed (in earlier, similar versions) by Robert Haas. Heikki Linnakangas and Michael Paquier implemented earlier designs that materially clarified the problem. Reviewed, in earlier designs, by Andrew Dunstan, Andres Freund, Alvaro Herrera, Tom Lane, Fujii Masao, and Simon Riggs. Reported by Martijn van Oosterhout. Discussion: https://postgr.es/m/20150702220524.GA9392@svana.org
2019-09-19Fix oversight in backpatch of 6cae9d2c10Alexander Korotkov
During backpatch of 6cae9d2c10 Float8GetDatum() was accidentally removed. This commit turns it back. Reported-by: Erik Rijkers Discussion: https://postgr.es/m/6d51305e1159241cabee132f7efc7eff%40xs4all.nl Author: Tom Lane Backpatch-through: from 11 to 9.5
2019-09-19Improve handling of NULLs in KNN-GiST and KNN-SP-GiSTAlexander Korotkov
This commit improves subject in two ways: * It removes ugliness of 02f90879e7, which stores distance values and null flags in two separate arrays after GISTSearchItem struct. Instead we pack both distance value and null flag in IndexOrderByDistance struct. Alignment overhead should be negligible, because we typically deal with at most few "col op const" expressions in ORDER BY clause. * It fixes handling of "col op NULL" expression in KNN-SP-GiST. Now, these expression are not passed to support functions, which can't deal with them. Instead, NULL result is implicitly assumed. It future we may decide to teach support functions to deal with NULL arguments, but current solution is bugfix suitable for backpatch. Reported-by: Nikita Glukhov Discussion: https://postgr.es/m/826f57ee-afc7-8977-c44c-6111d18b02ec%40postgrespro.ru Author: Nikita Glukhov Reviewed-by: Alexander Korotkov Backpatch-through: 9.4
2019-09-08Fix handling of NULL distances in KNN-GiSTAlexander Korotkov
In order to implement NULL LAST semantic GiST previously assumed distance to the NULL value to be Inf. However, our distance functions can return Inf and NaN for non-null values. In such cases, NULL LAST semantic appears to be broken. This commit fixes that by introducing separate array of null flags for distances. Backpatch to all supported versions. Discussion: https://postgr.es/m/CAPpHfdsNvNdA0DBS%2BwMpFrgwT6C3-q50sFVGLSiuWnV3FqOJuQ%40mail.gmail.com Author: Alexander Korotkov Backpatch-through: 9.4
2019-09-08Fix handling Inf and Nan values in GiST pairing heap comparatorAlexander Korotkov
Previously plain float comparison was used in GiST pairing heap. Such comparison doesn't provide proper ordering for value sets containing Inf and Nan values. This commit fixes that by usage of float8_cmp_internal(). Note, there is remaining problem with NULL distances, which are represented as Inf in pairing heap. It would be fixes in subsequent commit. Backpatch to all supported versions. Reported-by: Andrey Borodin Discussion: https://postgr.es/m/CAPpHfdsNvNdA0DBS%2BwMpFrgwT6C3-q50sFVGLSiuWnV3FqOJuQ%40mail.gmail.com Author: Alexander Korotkov Reviewed-by: Heikki Linnakangas Backpatch-through: 9.4
2019-07-10Fix variable initialization when using buffering build with GiSTMichael Paquier
This can cause valgrind to complain, as the flag marking a buffer as a temporary copy was not getting initialized. While on it, fill in with zeros newly-created buffer pages. This does not matter when loading a block from a temporary file, but it makes the push of an index tuple into a new buffer page safer. This has been introduced by 1d27dcf, so backpatch all the way down to 9.4. Author: Alexander Lakhin Discussion: https://postgr.es/m/15899-0d24fb273b3dd90c@postgresql.org Backpatch-through: 9.4
2018-12-21Check for conflicting queries during replay of gistvacuumpage()Alexander Korotkov
013ebc0a7b implements so-called GiST microvacuum. That is gistgettuple() marks index tuples as dead when kill_prior_tuple is set. Later, when new tuple insertion claims page space, those dead index tuples are physically deleted from page. When this deletion is replayed on standby, it might conflict with read-only queries. But 013ebc0a7b doesn't handle this. That may lead to disappearance of some tuples from read-only snapshots on standby. This commit implements resolving of conflicts between replay of GiST microvacuum and standby queries. On the master we implement new WAL record type XLOG_GIST_DELETE, which comprises necessary information. On stable releases we've to be tricky to keep WAL compatibility. Information required for conflict processing is just appended to data of XLOG_GIST_PAGE_UPDATE record. So, PostgreSQL version, which doesn't know about conflict processing, will just ignore that. Reported-by: Andres Freund Diagnosed-by: Andres Freund Discussion: https://postgr.es/m/20181212224524.scafnlyjindmrbe6%40alap3.anarazel.de Author: Alexander Korotkov Backpatch-through: 9.6
2018-03-02Make gistvacuumcleanup() count the actual number of index tuples.Tom Lane
Previously, it just returned the heap tuple count, which might be only an estimate, and would be completely the wrong thing if the index is partial. Since this function scans every index page anyway to find free pages, it's practically free to count the surviving index tuples. Let's do that and return an accurate count. This is easily visible as a wrong reltuples value for a partial GiST index following VACUUM, so back-patch to all supported branches. Andrey Borodin, reviewed by Michail Nikolaev Discussion: https://postgr.es/m/151956654251.6915.675951950408204404.pgcf@coridan.postgresql.org
2018-01-09Change some bogus PageGetLSN calls to BufferGetLSNAtomicAlvaro Herrera
As src/backend/access/transam/README says, PageGetLSN may only be called by processes holding either exclusive lock on buffer, or a shared lock on buffer plus buffer header lock. Therefore any place that only holds a shared buffer lock must use BufferGetLSNAtomic instead of PageGetLSN, which internally obtains buffer header lock prior to reading the LSN. A few callsites failed to comply with this rule. This was detected by running all tests under a new (not committed) assertion that verifies PageGetLSN locking contract. All but one of the callsites that failed the assertion are fixed by this patch. Remaining callsites were inspected manually and determined not to need any change. The exception (unfixed callsite) is in TestForOldSnapshot, which only has a Page argument, making it impossible to access the corresponding Buffer from it. Fixing that seems a much larger patch that will have to be done separately; and that's just as well, since it was only introduced in 9.6 and other bugs are much older. Some of these bugs are ancient; backpatch all the way back to 9.3. Authors: Jacob Champion, Asim Praveen, Ashwin Agrawal Reviewed-by: Michaël Paquier Discussion: https://postgr.es/m/CABAq_6GXgQDVu3u12mK9O5Xt5abBZWQ0V40LZCE+oUf95XyNFg@mail.gmail.com
2017-05-30Fix wording in amvalidate error messagesAlvaro Herrera
Remove some gratuituous message differences by making the AM name previously embedded in each message be a %s instead. While at it, get rid of terminology that's unclear and unnecessary in one message. Discussion: https://postgr.es/m/20170523001557.bq2hbq7hxyvyw62q@alvherre.pgsql
2017-05-04Fix pfree-of-already-freed-tuple when rescanning a GiST index-only scan.Tom Lane
GiST's getNextNearest() function attempts to pfree the previously-returned tuple if any (that is, scan->xs_hitup in HEAD, or scan->xs_itup in older branches). However, if we are rescanning a plan node after ending a previous scan early, those tuple pointers could be pointing to garbage, because they would be pointing into the scan's pageDataCxt or queueCxt which has been reset. In a debug build this reliably results in a crash, although I think it might sometimes accidentally fail to fail in production builds. To fix, clear the pointer field anyplace we reset a context it might be pointing into. This may be overkill --- I think probably only the queueCxt case is involved in this bug, so that resetting in gistrescan() would be sufficient --- but dangling pointers are generally bad news, so let's avoid them. Another plausible answer might be to just not bother with the pfree in getNextNearest(). The reconstructed tuples would go away anyway in the context resets, and I'm far from convinced that freeing them a bit earlier really saves anything meaningful. I'll stick with the original logic in this patch, but if we find more problems in the same area we should consider that approach. Per bug #14641 from Denis Smirnov. Back-patch to 9.5 where this logic was introduced. Discussion: https://postgr.es/m/20170504072034.24366.57688@wrigleys.postgresql.org
2017-02-06Fix typos in comments.Heikki Linnakangas
Backpatch to all supported versions, where applicable, to make backpatching of future fixes go more smoothly. Josh Soref Discussion: https://www.postgresql.org/message-id/CACZqfqCf+5qRztLPgmmosr-B0Ye4srWzzw_mo4c_8_B_mtjmJQ@mail.gmail.com
2016-09-20Fix outdated comments, GIST search queue is not an RBTree anymore.Heikki Linnakangas
The GiST search queue is implemented as a pairing heap rather than as Red-Black Tree, since 9.5 (commit e7032610). I neglected these comments in that commit.
2016-08-27Add macros to make AllocSetContextCreate() calls simpler and safer.Tom Lane
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>
2016-08-23Suppress compiler warnings in non-cassert builds.Tom Lane
With Asserts off, these variables are set but never used, resulting in warnings from pickier compilers. Fix that with our standard solution. Per report from Jeff Janes.
2016-08-15Final pgindent + perltidy run for 9.6.Tom Lane
2016-08-13Add SQL-accessible functions for inspecting index AM properties.Tom Lane
Per discussion, we should provide such functions to replace the lost ability to discover AM properties by inspecting pg_am (cf commit 65c5fcd35). The added functionality is also meant to displace any code that was looking directly at pg_index.indoption, since we'd rather not believe that the bit meanings in that field are part of any client API contract. As future-proofing, define the SQL API to not assume that properties that are currently AM-wide or index-wide will remain so unless they logically must be; instead, expose them only when inquiring about a specific index or even specific index column. Also provide the ability for an index AM to override the behavior. In passing, document pg_am.amtype, overlooked in commit 473b93287. Andrew Gierth, with kibitzing by me and others Discussion: <87mvl5on7n.fsf@news-spur.riddles.org.uk>
2016-07-28Message style improvementsPeter Eisentraut
2016-07-14Fix GiST index build for NaN values in geometric types.Tom Lane
GiST index build could go into an infinite loop when presented with boxes (or points, circles or polygons) containing NaN component values. This happened essentially because the code assumed that x == x is true for any "double" value x; but it's not true for NaNs. The looping behavior was not the only problem though: we also attempted to sort the items using simple double comparisons. Since NaNs violate the trichotomy law, qsort could (in principle at least) get arbitrarily confused and mess up the sorting of ordinary values as well as NaNs. And we based splitting choices on box size calculations that could produce NaNs, again resulting in undesirable behavior. To fix, replace all comparisons of doubles in this logic with float8_cmp_internal, which is NaN-aware and is careful to sort NaNs consistently, higher than any non-NaN. Also rearrange the box size calculation to not produce NaNs; instead it should produce an infinity for a box with NaN on one side and not-NaN on the other. I don't by any means claim that this solves all problems with NaNs in geometric values, but it should at least make GiST index insertion work reliably with such data. It's likely that the index search side of things still needs some work, and probably regular geometric operations too. But with this patch we're laying down a convention for how such cases ought to behave. Per bug #14238 from Guang-Dih Lei. Back-patch to 9.2; the code used before commit 7f3bd86843e5aad8 is quite different and doesn't lock up on my simple test case, nor on the submitter's dataset. Report: <20160708151747.1426.60150@wrigleys.postgresql.org> Discussion: <28685.1468246504@sss.pgh.pa.us>
2016-06-28Remove unused arguments in two GiST subroutinesAlvaro Herrera
These arguments became unused in commit 2c03216d8311. Noticed while skimming code for unrelated development. This is cosmetic, so no backpatch.
2016-06-09pgindent run for 9.6Robert Haas
2016-04-28Prevent to use magic constantsTeodor Sigaev
Use macroses for definition amstrategies/amsupport fields instead of hardcoded values. Author: Nikolay Shaplov with addition for contrib/bloom
2016-04-20Revert no-op changes to BufferGetPage()Kevin Grittner
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
2016-04-08Add the "snapshot too old" featureKevin Grittner
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.
2016-04-08Modify BufferGetPage() to prepare for "snapshot too old" featureKevin Grittner
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.
2016-04-08Revert CREATE INDEX ... INCLUDING ...Teodor Sigaev
It's not ready yet, revert two commits 690c543550b0d2852060c18d270cdb534d339d9a - unstable test output 386e3d7609c49505e079c40c65919d99feb82505 - patch itself
2016-04-08CREATE INDEX ... INCLUDING (column[, ...])Teodor Sigaev
Now indexes (but only B-tree for now) can contain "extra" column(s) which doesn't participate in index structure, they are just stored in leaf tuples. It allows to use index only scan by using single index instead of two or more indexes. Author: Anastasia Lubennikova with minor editorializing by me Reviewers: David Rowley, Peter Geoghegan, Jeff Janes
2016-02-02Fix lossy KNN GiST when ordering operator returns non-float8 value.Teodor Sigaev
KNN GiST with recheck flag should return to executor the same type as ordering operator, GiST detects this type by looking to return type of function which implements ordering operator. But occasionally detecting code works after replacing ordering operator function to distance support function. Distance support function always returns float8, so, detecting code get float8 instead of actual return type of ordering operator. Built-in opclasses don't have ordering operator which doesn't return non-float8 value, so, tests are impossible here, at least now. Backpatch to 9.5 where lozzy KNN was introduced. Author: Alexander Korotkov Report by: Artur Zakirov
2016-01-21Suppress compiler warning.Tom Lane
Given the limited range of i, these shifts should not cause any problem, but that apparently doesn't stop some compilers from whining about them. David Rowley
2016-01-21Improve index AMs' opclass validation procedures.Tom Lane
The amvalidate functions added in commit 65c5fcd353a859da were on the crude side. Improve them in a few ways: * Perform signature checking for operators and support functions. * Apply more thorough checks for missing operators and functions, where possible. * Instead of reporting problems as ERRORs, report most problems as INFO messages and make the amvalidate function return FALSE. This allows more than one problem to be discovered per run. * Report object names rather than OIDs, and work a bit harder on making the messages understandable. Also, remove a few more opr_sanity regression test queries that are now superseded by the amvalidate checks.
2016-01-19Fix assorted inconsistencies in GiST opclass support function declarations.Tom Lane
The conventions specified by the GiST SGML documentation were widely ignored. For example, the strategy-number argument for "consistent" and "distance" functions is specified to be a smallint, but most of the built-in support functions declared it as an integer, and for that matter the core code passed it using Int32GetDatum not Int16GetDatum. None of that makes any real difference at runtime, but it's quite confusing for newcomers to the code, and it makes it very hard to write an amvalidate() function that checks support function signatures. So let's try to instill some consistency here. Another similar issue is that the "query" argument is not of a single well-defined type, but could have different types depending on the strategy (corresponding to search operators with different righthand-side argument types). Some of the functions threw up their hands and declared the query argument as being of "internal" type, which surely isn't right ("any" would have been more appropriate); but the majority position seemed to be to declare it as being of the indexed data type, corresponding to a search operator with both input types the same. So I've specified a convention that that's what to do always. Also, the result of the "union" support function actually must be of the index's storage type, but the documentation suggested declaring it to return "internal", and some of the functions followed that. Standardize on telling the truth, instead. Similarly, standardize on declaring the "same" function's inputs as being of the storage type, not "internal". Also, somebody had forgotten to add the "recheck" argument to both the documentation of the "distance" support function and all of their SQL declarations, even though the C code was happily using that argument. Clean that up too. Fix up some other omissions in the docs too, such as documenting that union's second input argument is vestigial. So far as the errors in core function declarations go, we can just fix pg_proc.h and bump catversion. Adjusting the erroneous declarations in contrib modules is more debatable: in principle any change in those scripts should involve an extension version bump, which is a pain. However, since these changes are purely cosmetic and make no functional difference, I think we can get away without doing that.
2016-01-17Restructure index access method API to hide most of it at the C level.Tom Lane
This patch reduces pg_am to just two columns, a name and a handler function. All the data formerly obtained from pg_am is now provided in a C struct returned by the handler function. This is similar to the designs we've adopted for FDWs and tablesample methods. There are multiple advantages. For one, the index AM's support functions are now simple C functions, making them faster to call and much less error-prone, since the C compiler can now check function signatures. For another, this will make it far more practical to define index access methods in installable extensions. A disadvantage is that SQL-level code can no longer see attributes of index AMs; in particular, some of the crosschecks in the opr_sanity regression test are no longer possible from SQL. We've addressed that by adding a facility for the index AM to perform such checks instead. (Much more could be done in that line, but for now we're content if the amvalidate functions more or less replace what opr_sanity used to do.) We might also want to expose some sort of reporting functionality, but this patch doesn't do that. Alexander Korotkov, reviewed by Petr Jelínek, and rather heavily editorialized on by me.
2016-01-02Update copyright for 2016Bruce Momjian
Backpatch certain files through 9.1
2015-09-17Fix bug introduced by microvacuum for GiSTTeodor Sigaev
Commit 013ebc0a7b7ea9c1b1ab7a3d4dd75ea121ea8ba7 introduces microvacuum for GiST, deletetion of tuple marked LP_DEAD uses IndexPageMultiDelete while recovery code uses IndexPageTupleDelete in loop. This causes a difference in offset numbers of tuples to delete. Patch introduces usage of IndexPageMultiDelete in GiST except gistplacetopage() where only one tuple is deleted at once. That also slightly improve performance, because IndexPageMultiDelete is more effective. Patch changes WAL format, so bump wal page magic. Bug report from Jeff Janes Diagnostic and patch by Anastasia Lubennikova and me
2015-09-09Fix oversight in 013ebc0a7b7ea9c1b1ab7a3d4dd75ea121ea8ba7 commitTeodor Sigaev
Declaration of varibale inside ÓÝ×Õ
2015-09-09Microvacuum for GISTTeodor Sigaev
Mark index tuple as dead if it's pointed by kill_prior_tuple during ordinary (search) scan and remove it during insert process if there is no enough space for new tuple to insert. This improves select performance because index will not return tuple marked as dead and improves insert performance because it reduces number of page split. Anastasia Lubennikova <a.lubennikova@postgrespro.ru> with minor editorialization by me
2015-09-05Fix misc typos.Heikki Linnakangas
Oskari Saarenmaa. Backpatch to stable branches where applicable.
2015-05-23pgindent run for 9.5Bruce Momjian
2015-05-23Still more fixes for lossy-GiST-distance-functions patch.Tom Lane
Fix confusion in documentation, substantial memory leakage if float8 or float4 are pass-by-reference, and assorted comments that were obsoleted by commit 98edd617f3b62a02cb2df9b418fcc4ece45c7ec0.
2015-05-15Move strategy numbers to include/access/stratnum.hAlvaro Herrera
For upcoming BRIN opclasses, it's convenient to have strategy numbers defined in a single place. Since there's nothing appropriate, create it. The StrategyNumber typedef now lives there, as well as existing strategy numbers for B-trees (from skey.h) and R-tree-and-friends (from gist.h). skey.h is forced to include stratnum.h because of the StrategyNumber typedef, but gist.h is not; extensions that currently rely on gist.h for rtree strategy numbers might need to add a new A few .c files can stop including skey.h and/or gist.h, which is a nice side benefit. Per discussion: https://www.postgresql.org/message-id/20150514232132.GZ2523@alvh.no-ip.org Authored by Emre Hasegeli and Álvaro. (It's not clear to me why bootscanner.l has any #include lines at all.)
2015-05-15Fix datatype confusion with the new lossy GiST distance functions.Heikki Linnakangas
We can only support a lossy distance function when the distance function's datatype is comparable with the original ordering operator's datatype. The distance function always returns a float8, so we are limited to float8, and float4 (by a hard-coded cast of the float8 to float4). In light of this limitation, it seems like a good idea to have a separate 'recheck' flag for the ORDER BY expressions, so that if you have a non-lossy distance function, it still works with lossy quals. There are cases like that with the build-in or contrib opclasses, but it's plausible. There was a hidden assumption that the ORDER BY values returned by GiST match the original ordering operator's return type, but there are plenty of examples where that's not true, e.g. in btree_gist and pg_trgm. As long as the distance function is not lossy, we can tolerate that and just not return the distance to the executor (or rather, always return NULL). The executor doesn't need the distances if there are no lossy results. There was another little bug: the recheck variable was not initialized before calling the distance function. That revealed the bigger issue, as the executor tried to reorder tuples that didn't need reordering, and that failed because of the datatype mismatch.
2015-05-15Allow GiST distance function to return merely a lower-bound.Heikki Linnakangas
The distance function can now set *recheck = false, like index quals. The executor will then re-check the ORDER BY expressions, and use a queue to reorder the results on the fly. This makes it possible to do kNN-searches on polygons and circles, which don't store the exact value in the index, but just a bounding box. Alexander Korotkov and me
2015-03-26Fix GiST index-only scans for opclasses with different storage type.Heikki Linnakangas
We cannot use the index's tuple descriptor directly to describe the index tuples returned in an index-only scan. That's because the index might use a different datatype for the values stored on disk than the type originally indexed. As long as they were both pass-by-ref, it worked, but will not work for pass-by-value types of different sizes. I noticed this as a crash when I started hacking a patch to add fetch methods to btree_gist.
2015-03-26Add support for index-only scans in GiST.Heikki Linnakangas
This adds a new GiST opclass method, 'fetch', which is used to reconstruct the original Datum from the value stored in the index. Also, the 'canreturn' index AM interface function gains a new 'attno' argument. That makes it possible to use index-only scans on a multi-column index where some of the opclasses support index-only scans but some do not. This patch adds support in the box and point opclasses. Other opclasses can added later as follow-on patches (btree_gist would be particularly interesting). Anastasia Lubennikova, with additional fixes and modifications by me.
2015-03-26Minor cleanup of GiST code, for readability.Heikki Linnakangas
Remove the gistcentryinit function, inlining the relevant part of it into the only caller.
2015-02-17Fix knn-GiST queue comparison function to return heap tuples first.Heikki Linnakangas
The part of the comparison function that was supposed to keep heap tuples ahead of index items was backwards. It would not lead to incorrect results, but it is more efficient to return heap tuples first, before scanning more index pages, when both have the same distance. Alexander Korotkov
2015-01-28Remove dead NULL-pointer checks in GiST code.Heikki Linnakangas
gist_poly_compress() and gist_circle_compress() checked for a NULL-pointer key argument, but that was dead code; the gist code never passes a NULL-pointer to the "compress" method. This commit also removes a documentation note added in commit a0a3883, about doing NULL-pointer checks in the "compress" method. It was added based on the fact that some implementations were doing NULL-pointer checks, but those checks were unnecessary in the first place. The NULL-pointer check in gbt_var_same() function was also unnecessary. The arguments to the "same" method come from the "compress", "union", or "picksplit" methods, but none of them return a NULL pointer. None of this is to be confused with SQL NULL values. Those are dealt with by the gist machinery, and are never passed to the GiST opclass methods. Michael Paquier
2015-01-06Update copyright for 2015Bruce Momjian
Backpatch certain files through 9.0