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* Add stratnum GiST support functionPeter Eisentraut2024-01-19
| | | | | | | | | | | | | | | | | | This is support function 12 for the GiST AM and translates "well-known" RT*StrategyNumber values into whatever strategy number is used by the opclass (since no particular numbers are actually required). We will use this to support temporal PRIMARY KEY/UNIQUE/FOREIGN KEY/FOR PORTION OF functionality. This commit adds two implementations, one for internal GiST opclasses (just an identity function) and another for btree_gist opclasses. It updates btree_gist from 1.7 to 1.8, adding the support function for all its opclasses. Author: Paul A. Jungwirth <pj@illuminatedcomputing.com> Reviewed-by: Peter Eisentraut <peter@eisentraut.org> Reviewed-by: jian he <jian.universality@gmail.com> Discussion: https://www.postgresql.org/message-id/flat/CA+renyUApHgSZF9-nd-a0+OPGharLQLO=mDHcY4_qQ0+noCUVg@mail.gmail.com
* Optimize vacuuming of relations with no indexes.Robert Haas2024-01-18
| | | | | | | | | | | | If there are no indexes on a relation, items can be marked LP_UNUSED instead of LP_DEAD when pruning. This significantly reduces WAL volume, since we no longer need to emit one WAL record for pruning and a second to change the LP_DEAD line pointers thus created to LP_UNUSED. Melanie Plageman, reviewed by Andres Freund, Peter Geoghegan, and me Discussion: https://postgr.es/m/CAAKRu_bgvb_k0gKOXWzNKWHt560R0smrGe3E8zewKPs8fiMKkw%40mail.gmail.com
* Add try_index_open(), conditional variant of index_open()Michael Paquier2024-01-18
| | | | | | | | | | | | | | try_index_open() is able to open an index if its relkind fits, except that it would return NULL instead of generated an error if the relation does not exist. This new routine will be used by an upcoming patch to make REINDEX on partitioned relations more robust when an index in a partition tree is dropped. Extracted from a larger patch by the same author. Author: Fei Changhong Discussion: https://postgr.es/m/tencent_6A52106095ACDE55333E3AD33F304C0C3909@qq.com Backpatch-through: 14
* Update copyright for 2024Bruce Momjian2024-01-03
| | | | | | | | Reported-by: Michael Paquier Discussion: https://postgr.es/m/ZZKTDPxBBMt3C0J9@paquier.xyz Backpatch-through: 12
* gist: fix typo "split(t)ed" -> "split"Robert Haas2024-01-02
| | | | | | Dagfinn Ilmari Mannsåker, reviewed by Shubham Khanna. Discussion: http://postgr.es/m/87le9fmi01.fsf@wibble.ilmari.org
* Improvements and fixes for e0b1ee17dcAlexander Korotkov2023-12-27
| | | | | | | | | | | | | | | | | | | | | | e0b1ee17dc introduced optimization for matching B-tree scan keys required for the directional scan. However, it incorrectly assumed that all keys required for opposite direction scan are satisfied by _bt_first(). It has been illustrated that with multiple scan keys over the same column, a lesser one (according to the scan direction) could win leaving the other one unsatisfied. Instead of relying on _bt_first() this commit introduces code that memorizes whether there was at least one match on the page. If that's true we know that keys required for opposite-direction scan are satisfied as soon as corresponding values are not NULLs. Also, this commit simplifies the description for the optimization of keys required for the current direction scan. Now the flag used for this is named continuescanPrechecked and means exactly that *continuescan flag is known to be true for the last item on the page. Reported-by: Peter Geoghegan Discussion: https://postgr.es/m/CAH2-Wzn0LeLcb1PdBnK0xisz8NpHkxRrMr3NWJ%2BKOK-WZ%2BQtTQ%40mail.gmail.com Reviewed-by: Pavel Borisov
* Remove BTScanOpaqueData.firstPageAlexander Korotkov2023-12-27
| | | | | | | | | | It's not necessary to keep the firstPage flag as a field of BTScanOpaqueData. This commit makes it an argument of the _bt_readpage() function. We can easily distinguish first-time and repeated calls (within the scan) of this function. Reported-by: Peter Geoghegan Discussion: https://postgr.es/m/CAH2-Wzk4SOsw%2BtHuTFiz8U9Jqj-R77rYPkhWKODCBb1mdHACXA%40mail.gmail.com Reviewed-by: Pavel Borisov
* Add support for incremental backup.Robert Haas2023-12-20
| | | | | | | | | | | | | | | | | | | | | | To take an incremental backup, you use the new replication command UPLOAD_MANIFEST to upload the manifest for the prior backup. This prior backup could either be a full backup or another incremental backup. You then use BASE_BACKUP with the INCREMENTAL option to take the backup. pg_basebackup now has an --incremental=PATH_TO_MANIFEST option to trigger this behavior. An incremental backup is like a regular full backup except that some relation files are replaced with files with names like INCREMENTAL.${ORIGINAL_NAME}, and the backup_label file contains additional lines identifying it as an incremental backup. The new pg_combinebackup tool can be used to reconstruct a data directory from a full backup and a series of incremental backups. Patch by me. Reviewed by Matthias van de Meent, Dilip Kumar, Jakub Wartak, Peter Eisentraut, and Álvaro Herrera. Thanks especially to Jakub for incredibly helpful and extensive testing. Discussion: http://postgr.es/m/CA+TgmoYOYZfMCyOXFyC-P+-mdrZqm5pP2N7S-r0z3_402h9rsA@mail.gmail.com
* Add a new WAL summarizer process.Robert Haas2023-12-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | When active, this process writes WAL summary files to $PGDATA/pg_wal/summaries. Each summary file contains information for a certain range of LSNs on a certain TLI. For each relation, it stores a "limit block" which is 0 if a relation is created or destroyed within a certain range of WAL records, or otherwise the shortest length to which the relation was truncated during that range of WAL records, or otherwise InvalidBlockNumber. In addition, it stores a list of blocks which have been modified during that range of WAL records, but excluding blocks which were removed by truncation after they were modified and never subsequently modified again. In other words, it tells us which blocks need to copied in case of an incremental backup covering that range of WAL records. But this doesn't yet add the capability to actually perform an incremental backup; the next patch will do that. A new parameter summarize_wal enables or disables this new background process. The background process also automatically deletes summary files that are older than wal_summarize_keep_time, if that parameter has a non-zero value and the summarizer is configured to run. Patch by me, with some design help from Dilip Kumar and Andres Freund. Reviewed by Matthias van de Meent, Dilip Kumar, Jakub Wartak, Peter Eisentraut, and Álvaro Herrera. Discussion: http://postgr.es/m/CA+TgmoYOYZfMCyOXFyC-P+-mdrZqm5pP2N7S-r0z3_402h9rsA@mail.gmail.com
* Remove some unnecessary includes of "access/xlog_internal.h"Peter Eisentraut2023-12-10
| | | | | | | | | | There were a few places where access/xlog_internal.h was apparently included unnecessarily. In some of those places, a more specific header file (that somehow came in via access/xlog_internal.h) can be used instead. Reviewed-by: Heikki Linnakangas <hlinnaka@iki.fi> Discussion: https://www.postgresql.org/message-id/flat/a56a6eec-eb14-471b-9570-3cac23603964%40eisentraut.org
* Optimize nbtree backward scan boundary cases.Peter Geoghegan2023-12-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Teach _bt_binsrch (and related helper routines like _bt_search and _bt_compare) about the initial positioning requirements of backward scans. Routines like _bt_binsrch already know all about "nextkey" searches, so it seems natural to teach them about "goback"/backward searches, too. These concepts are closely related, and are much easier to understand when discussed together. Now that certain implementation details are hidden from _bt_first, it's straightforward to add a new optimization: backward scans using the < strategy now avoid extra leaf page accesses in certain "boundary cases". Consider the following example, which uses the tenk1 table (and its tenk1_hundred index) from the standard regression tests: SELECT * FROM tenk1 WHERE hundred < 12 ORDER BY hundred DESC LIMIT 1; Before this commit, nbtree would scan two leaf pages, even though it was only really necessary to scan one leaf page. We'll now descend straight to the leaf page containing a (12, -inf) high key instead. The scan will locate matching non-pivot tuples with "hundred" values starting from the value 11. The scan won't waste a page access on the right sibling leaf page, which cannot possibly contain any matching tuples. You can think of the optimization added by this commit as disabling an optimization (the _bt_compare "!pivotsearch" behavior that was added to Postgres 12 in commit dd299df8) for a small subset of cases where it was always counterproductive. Equivalently, you can think of the new optimization as extending the "pivotsearch" behavior that page deletion by VACUUM has long required (since the aforementioned Postgres 12 commit went in) to other, similar cases. Obviously, this isn't strictly necessary for these new cases (unlike VACUUM, _bt_first is prepared to move the scan to the left once on the leaf level), but the underlying principle is the same. Author: Peter Geoghegan <pg@bowt.ie> Reviewed-By: Matthias van de Meent <boekewurm+postgres@gmail.com> Discussion: https://postgr.es/m/CAH2-Wz=XPzM8HzaLPq278Vms420mVSHfgs9wi5tjFKHcapZCEw@mail.gmail.com
* Allow parallel CREATE INDEX for BRIN indexesTomas Vondra2023-12-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Allow using multiple worker processes to build BRIN index, which until now was supported only for BTREE indexes. For large tables this often results in significant speedup when the build is CPU-bound. The work is split in a simple way - each worker builds BRIN summaries on a subset of the table, determined by the regular parallel scan used to read the data, and feeds them into a shared tuplesort which sorts them by blkno (start of the range). The leader then reads this sorted stream of ranges, merges duplicates (which may happen if the parallel scan does not align with BRIN pages_per_range), and adds the resulting ranges into the index. The number of duplicate results produced by workers (requiring merging in the leader process) should be fairly small, thanks to how parallel scans assign chunks to workers. The likelihood of duplicate results may increase for higher pages_per_range values, but then there are fewer page ranges in total. In any case, we expect the merging to be much cheaper than summarization, so this should be a win. Most of the parallelism infrastructure is a simplified copy of the code used by BTREE indexes, omitting the parts irrelevant for BRIN indexes (e.g. uniqueness checks). This also introduces a new index AM flag amcanbuildparallel, determining whether to attempt to start parallel workers for the index build. Original patch by me, with reviews and substantial reworks by Matthias van de Meent, certainly enough to make him a co-author. Author: Tomas Vondra, Matthias van de Meent Reviewed-by: Matthias van de Meent Discussion: https://postgr.es/m/c2ee7d69-ce17-43f2-d1a0-9811edbda6e6%40enterprisedb.com
* Rename ShmemVariableCache to TransamVariablesHeikki Linnakangas2023-12-08
| | | | | | | | The old name was misleading: It's not a cache, the values kept in the struct are the authoritative source. Reviewed-by: Tristan Partin, Richard Guo Discussion: https://www.postgresql.org/message-id/6537d63d-4bb5-46f8-9b5d-73a8ba4720ab@iki.fi
* Initialize ShmemVariableCache like other shmem areasHeikki Linnakangas2023-12-08
| | | | | | | For sake of consistency. Reviewed-by: Tristan Partin, Richard Guo Discussion: https://www.postgresql.org/message-id/6537d63d-4bb5-46f8-9b5d-73a8ba4720ab@iki.fi
* Index SLRUs by 64-bit integers rather than by 32-bit integersAlexander Korotkov2023-11-29
| | | | | | | | | | | | | | | | | | We've had repeated bugs in the area of handling SLRU wraparound in the past, some of which have caused data loss. Switching to an indexing system for SLRUs that does not wrap around should allow us to get rid of a whole bunch of problems and improve the overall reliability of the system. This particular patch however only changes the indexing and doesn't address the wraparound per se. This is going to be done in the following patches. Author: Maxim Orlov, Aleksander Alekseev, Alexander Korotkov, Teodor Sigaev Author: Nikita Glukhov, Pavel Borisov, Yura Sokolov Reviewed-by: Jacob Champion, Heikki Linnakangas, Alexander Korotkov Reviewed-by: Japin Li, Pavel Borisov, Tom Lane, Peter Eisentraut, Andres Freund Reviewed-by: Andrey Borodin, Dilip Kumar, Aleksander Alekseev Discussion: https://postgr.es/m/CACG%3DezZe1NQSCnfHOr78AtAZxJZeCvxrts0ygrxYwe%3DpyyjVWA%40mail.gmail.com Discussion: https://postgr.es/m/CAJ7c6TPDOYBYrnCAeyndkBktO0WG2xSdYduTF0nxq%2BvfkmTF5Q%40mail.gmail.com
* Fix assertions with RI triggers in heap_update and heap_delete.Heikki Linnakangas2023-11-28
| | | | | | | | | | | | If the tuple being updated is not visible to the crosscheck snapshot, we return TM_Updated but the assertions would not hold in that case. Move them to before the cross-check. Fixes bug #17893. Backpatch to all supported versions. Author: Alexander Lakhin Backpatch-through: 12 Discussion: https://www.postgresql.org/message-id/17893-35847009eec517b5%40postgresql.org
* Fix comment in tableam.h about GetHeapamTableAmRoutine()Michael Paquier2023-11-28
| | | | | | | | This routine is located in heapam_handler.c, not tableamapi.c. Issue noted while hacking the area for a different patch. Reviewed-by: Richard Guo Discussion: https://postgr.es/m/ZWQuHltp2KS_0Cct@paquier.xyz
* Reuse BrinDesc and BrinRevmap in brininsertTomas Vondra2023-11-25
| | | | | | | | | | | | | | | | The brininsert code used to initialize (and destroy) BrinDesc and BrinRevmap for each tuple, which is not free. This patch initializes these structures only once, and reuses them for all inserts in the same command. The data is passed through indexInfo->ii_AmCache. This also introduces an optional AM callback "aminsertcleanup" that allows performing custom cleanup in case simply pfree-ing ii_AmCache is not sufficient (which is the case when the cache contains TupleDesc, Buffers, and so on). Author: Soumyadeep Chakraborty Reviewed-by: Alvaro Herrera, Matthias van de Meent, Tomas Vondra Discussion: https://postgr.es/m/CAE-ML%2B9r2%3DaO1wwji1sBN9gvPz2xRAtFUGfnffpd0ZqyuzjamA%40mail.gmail.com
* Add trailing commas to enum definitionsPeter Eisentraut2023-10-26
| | | | | | | | | | | | | | | | | | | | Since C99, there can be a trailing comma after the last value in an enum definition. A lot of new code has been introducing this style on the fly. Some new patches are now taking an inconsistent approach to this. Some add the last comma on the fly if they add a new last value, some are trying to preserve the existing style in each place, some are even dropping the last comma if there was one. We could nudge this all in a consistent direction if we just add the trailing commas everywhere once. I omitted a few places where there was a fixed "last" value that will always stay last. I also skipped the header files of libpq and ecpg, in case people want to use those with older compilers. There were also a small number of cases where the enum type wasn't used anywhere (but the enum values were), which ended up confusing pgindent a bit, so I left those alone. Discussion: https://www.postgresql.org/message-id/flat/386f8c45-c8ac-4681-8add-e3b0852c1620%40eisentraut.org
* 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
* During online checkpoints, insert XLOG_CHECKPOINT_REDO at redo point.Robert Haas2023-10-19
| | | | | | | | | | | | | | | | | | | | | | | | | | This allows tools that read the WAL sequentially to identify (possible) redo points when they're reached, rather than only being able to detect them in retrospect when XLOG_CHECKPOINT_ONLINE is found, possibly much later in the WAL stream. There are other possible applications as well; see the discussion links below. Any redo location that precedes the checkpoint location should now point to an XLOG_CHECKPOINT_REDO record, so add a cross-check to verify this. While adjusting the code in CreateCheckPoint() for this patch, I made it call WALInsertLockAcquireExclusive a bit later than before, since there appears to be no need for it to be held while checking whether the system is idle, whether this is an end-of-recovery checkpoint, or what the current timeline is. Bump XLOG_PAGE_MAGIC. Patch by me, based in part on earlier work from Dilip Kumar. Review by Dilip Kumar, Amit Kapila, Andres Freund, and Michael Paquier. Discussion: http://postgr.es/m/CA+TgmoYy-Vc6G9QKcAKNksCa29cv__czr+N9X_QCxEfQVpp_8w@mail.gmail.com Discussion: http://postgr.es/m/20230614194717.jyuw3okxup4cvtbt%40awork3.anarazel.de Discussion: http://postgr.es/m/CA+hUKG+b2ego8=YNW2Ohe9QmSiReh1-ogrv8V_WZpJTqP3O+2w@mail.gmail.com
* Improve the naming in wal_sync_method code.Nathan Bossart2023-10-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | * sync_method is renamed to wal_sync_method. * sync_method_options[] is renamed to wal_sync_method_options[]. * assign_xlog_sync_method() is renamed to assign_wal_sync_method(). * The names of the available synchronization methods are now prefixed with "WAL_SYNC_METHOD_" and have been moved into a WalSyncMethod enum. * PLATFORM_DEFAULT_SYNC_METHOD is renamed to PLATFORM_DEFAULT_WAL_SYNC_METHOD, and DEFAULT_SYNC_METHOD is renamed to DEFAULT_WAL_SYNC_METHOD. These more descriptive names help distinguish the code for wal_sync_method from the code for DataDirSyncMethod (e.g., the recovery_init_sync_method configuration parameter and the --sync-method option provided by several frontend utilities). This change also prevents name collisions between the aforementioned sets of code. Since this only improves the naming of internal identifiers, there should be no behavior change. Author: Maxim Orlov Discussion: https://postgr.es/m/CACG%3DezbL1gwE7_K7sr9uqaCGkWhmvRTcTEnm3%2BX1xsRNwbXULQ%40mail.gmail.com
* Add const to values and nulls argumentsPeter Eisentraut2023-10-10
| | | | | | | This excludes any changes that would change the external AM APIs. Reviewed-by: Aleksander Alekseev <aleksander@timescale.com> Discussion: https://www.postgresql.org/message-id/flat/14c31f4a-0347-0805-dce8-93a9072c05a5%40eisentraut.org
* Skip checking of scan keys required for directional scan in B-treeAlexander Korotkov2023-10-06
| | | | | | | | | | | | | | | | | | | | | Currently, B-tree code matches every scan key to every item on the page. Imagine the ordered B-tree scan for the query like this. SELECT * FROM tbl WHERE col > 'a' AND col < 'b' ORDER BY col; The (col > 'a') scan key will be always matched once we find the location to start the scan. The (col < 'b') scan key will match every item on the page as long as it matches the last item on the page. This patch implements prechecking of the scan keys required for directional scan on beginning of page scan. If precheck is successful we can skip this scan keys check for the items on the page. That could lead to significant acceleration especially if the comparison operator is expensive. Idea from patch by Konstantin Knizhnik. Discussion: https://postgr.es/m/079c3f8e-3371-abe2-e93c-fc8a0ae3f571%40garret.ru Reviewed-by: Peter Geoghegan, Pavel Borisov
* Move BuildDescForRelation() from tupdesc.c to tablecmds.cPeter Eisentraut2023-10-05
| | | | | | | | | | | | | | BuildDescForRelation() main job is to convert ColumnDef lists to pg_attribute/tuple descriptor arrays, which is really mostly an internal subroutine of DefineRelation() and some related functions, which is more the remit of tablecmds.c and doesn't have much to do with the basic tuple descriptor interfaces in tupdesc.c. This is also supported by observing the header includes we can remove in tupdesc.c. By moving it over, we can also (in the future) make BuildDescForRelation() use more internals of tablecmds.c that are not sensible to be exposed in tupdesc.c. Discussion: https://www.postgresql.org/message-id/flat/52a125e4-ff9a-95f5-9f61-b87cf447e4da@eisentraut.org
* Remove retry loop in heap_page_prune().Robert Haas2023-10-02
| | | | | | | | | | | | | | | The retry loop is needed because heap_page_prune() calls HeapTupleSatisfiesVacuum() and then lazy_scan_prune() does the same thing again, and they might get different answers due to concurrent clog updates. But this patch makes heap_page_prune() return the HeapTupleSatisfiesVacuum() results that it computed back to the caller, which allows lazy_scan_prune() to avoid needing to recompute those values in the first place. That's nice both because it eliminates the need for a retry loop and also because it's cheaper. Melanie Plageman, reviewed by David Geier, Andres Freund, and me. Discussion: https://postgr.es/m/CAAKRu_br124qsGJieuYA0nGjywEukhK1dKBfRdby_4yY3E9SXA%40mail.gmail.com
* Add rmgrdesc READMEHeikki Linnakangas2023-10-02
| | | | | | | | | | In the README, briefly explain what rmgrdesc functions are, and why they are in a separate directory. Commit c03c2eae0a added some guidelines on the preferred output format; move that to the README too. Reviewed-by: Melanie Plageman, Peter Geoghegan Discussion: https://www.postgresql.org/message-id/9159daf7-f42d-781b-458f-1b2cf32cb256%40iki.fi
* Correct assertion and comments about XLogRecordMaxSize.Noah Misch2023-10-01
| | | | | | The largest allocation, of xl_tot_len+8192, is in allocate_recordbuf(). Discussion: https://postgr.es/m/20230812211327.GB2326466@rfd.leadboat.com
* Fix btmarkpos/btrestrpos array key wraparound bug.Peter Geoghegan2023-09-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | nbtree's mark/restore processing failed to correctly handle an edge case involving array key advancement and related search-type scan key state. Scans with ScalarArrayScalarArrayOpExpr quals requiring mark/restore processing (for a merge join) could incorrectly conclude that an affected array/scan key must not have advanced during the time between marking and restoring the scan's position. As a result of all this, array key handling within btrestrpos could skip a required call to _bt_preprocess_keys(). This confusion allowed later primitive index scans to overlook tuples matching the true current array keys. The scan's search-type scan keys would still have spurious values corresponding to the final array element(s) -- not values matching the first/now-current array element(s). To fix, remember that "array key wraparound" has taken place during the ongoing btrescan in a flag variable stored in the scan's state, and use that information at the point where btrestrpos decides if another call to _bt_preprocess_keys is required. Oversight in commit 70bc5833, which taught nbtree to handle array keys during mark/restore processing, but missed this subtlety. That commit was itself a bug fix for an issue in commit 9e8da0f7, which taught nbtree to handle ScalarArrayOpExpr quals natively. Author: Peter Geoghegan <pg@bowt.ie> Discussion: https://postgr.es/m/CAH2-WzkgP3DDRJxw6DgjCxo-cu-DKrvjEv_ArkP2ctBJatDCYg@mail.gmail.com Backpatch: 11- (all supported branches).
* Return data from heap_page_prune via a struct.Robert Haas2023-09-28
| | | | | | | | | | | Previously, one of the values in the struct was returned as the return value, and another was returned via an output parameter. In preparation for returning more stuff, consolidate both values into a struct returned via an output parameter. Melanie Plageman, reviewed by Andres Freund and by me. Discussion: https://postgr.es/m/CAAKRu_br124qsGJieuYA0nGjywEukhK1dKBfRdby_4yY3E9SXA%40mail.gmail.com
* Add TupleDescGetDefault()Peter Eisentraut2023-09-27
| | | | | | | | | | | | | | | This unifies some repetitive code. Note: I didn't push the "not found" error message into the new function, even though all existing callers would be able to make use of it. Using the existing error handling as-is would probably require exposing the Relation type via tupdesc.h, which doesn't seem desirable. (Or even if we changed it to just report the OID, it would inject the concept of a relation containing the tuple descriptor into tupdesc.h, which might be a layering violation. Perhaps some further improvements could be considered here separately.) Discussion: https://www.postgresql.org/message-id/flat/52a125e4-ff9a-95f5-9f61-b87cf447e4da%40eisentraut.org
* MergeAttributes() and related variable renamingPeter Eisentraut2023-09-26
| | | | | | | Mainly, rename "schema" to "columns" and related changes. The previous naming has long been confusing. Discussion: https://www.postgresql.org/message-id/flat/52a125e4-ff9a-95f5-9f61-b87cf447e4da%40eisentraut.org
* Remove some more "snapshot too old" vestiges.Thomas Munro2023-09-08
| | | | | | | | | Commit f691f5b8 removed the logic, but left behind some now-useless Snapshot arguments to various AM-internal functions, and missed a couple of comments. Reported-by: Peter Geoghegan <pg@bowt.ie> Discussion: https://postgr.es/m/CAH2-Wznj9qSNXZ1P1uWTUD_FeaTezbUazb416EPwi4Qr_jR_6A%40mail.gmail.com
* Remove the "snapshot too old" feature.Thomas Munro2023-09-05
| | | | | | | | | | | | | | | | | Remove the old_snapshot_threshold setting and mechanism for producing the error "snapshot too old", originally added by commit 848ef42b. Unfortunately it had a number of known problems in terms of correctness and performance, mostly reported by Andres in the course of his work on snapshot scalability. We agreed to remove it, after a long period without an active plan to fix it. This is certainly a desirable feature, and someone might propose a new or improved implementation in the future. Reported-by: Andres Freund <andres@anarazel.de> Discussion: https://postgr.es/m/CACG%3DezYV%2BEvO135fLRdVn-ZusfVsTY6cH1OZqWtezuEYH6ciQA%40mail.gmail.com Discussion: https://postgr.es/m/20200401064008.qob7bfnnbu4w5cw4%40alap3.anarazel.de Discussion: https://postgr.es/m/CA%2BTgmoY%3Daqf0zjTD%2B3dUWYkgMiNDegDLFjo%2B6ze%3DWtpik%2B3XqA%40mail.gmail.com
* hio: Take number of prior relation extensions into accountAndres Freund2023-08-14
| | | | | | | | | | | | | | | | | | | | | | | | The new relation extension logic, introduced in 00d1e02be24, could lead to slowdowns in some scenarios. E.g., when loading narrow rows into a table using COPY, the caller of RelationGetBufferForTuple() will only request a small number of pages. Without concurrency, we just extended using pwritev() in that case. However, if there is *some* concurrency, we switched between extending by a small number of pages and a larger number of pages, depending on the number of waiters for the relation extension logic. However, some filesystems, XFS in particular, do not perform well when switching between extending files using fallocate() and pwritev(). To avoid that issue, remember the number of prior relation extensions in BulkInsertState and extend more aggressively if there were prior relation extensions. That not just avoids the aforementioned slowdown, but also leads to noticeable performance gains in other situations, primarily due to extending more aggressively when there is no concurrency. I should have done it this way from the get go. Reported-by: Masahiko Sawada <sawada.mshk@gmail.com> Author: Andres Freund <andres@anarazel.de> Discussion: https://postgr.es/m/CAD21AoDvDmUQeJtZrau1ovnT_smN940=Kp6mszNGK3bq9yRN6g@mail.gmail.com Backpatch: 16-, where the new relation extension code was added
* nbtree: Allocate new pages in separate function.Peter Geoghegan2023-06-10
| | | | | | | | | | | | | | | | | | | | | | | | Split nbtree's _bt_getbuf function is two: code that read locks or write locks existing pages remains in _bt_getbuf, while code that deals with allocating new pages is moved to a new, dedicated function called _bt_allocbuf. This simplifies most _bt_getbuf callers, since it is no longer necessary for them to pass a heaprel argument. Many of the changes to nbtree from commit 61b313e4 can be reverted. This minimizes the divergence between HEAD/PostgreSQL 16 and earlier release branches. _bt_allocbuf replaces the previous nbtree idiom of passing P_NEW to _bt_getbuf. There are only 3 affected call sites, all of which continue to pass a heaprel for recovery conflict purposes. Note that nbtree's use of P_NEW was superficial; nbtree never actually relied on the P_NEW code paths in bufmgr.c, so this change is strictly mechanical. GiST already took the same approach; it has a dedicated function for allocating new pages called gistNewBuffer(). That factor allowed commit 61b313e4 to make much more targeted changes to GiST. Author: Peter Geoghegan <pg@bowt.ie> Reviewed-By: Heikki Linnakangas <hlinnaka@iki.fi> Discussion: https://postgr.es/m/CAH2-Wz=8Z9qY58bjm_7TAHgtW6RzZ5Ke62q5emdCEy9BAzwhmg@mail.gmail.com
* Pre-beta mechanical code beautification.Tom Lane2023-05-19
| | | | | | | | | | | | | | | Run pgindent, pgperltidy, and reformat-dat-files. This set of diffs is a bit larger than typical. We've updated to pg_bsd_indent 2.1.2, which properly indents variable declarations that have multi-line initialization expressions (the continuation lines are now indented one tab stop). We've also updated to perltidy version 20230309 and changed some of its settings, which reduces its desire to add whitespace to lines to make assignments etc. line up. Going forward, that should make for fewer random-seeming changes to existing code. Discussion: https://postgr.es/m/20230428092545.qfb3y5wcu4cm75ur@alvherre.pgsql
* Fix handling of empty ranges and NULLs in BRINTomas Vondra2023-05-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BRIN indexes did not properly distinguish between summaries for empty (no rows) and all-NULL ranges, treating them as essentially the same thing. Summaries were initialized with allnulls=true, and opclasses simply reset allnulls to false when processing the first non-NULL value. This however produces incorrect results if the range starts with a NULL value (or a sequence of NULL values), in which case we forget the range contains NULL values when adding the first non-NULL value. This happens because the allnulls flag is used for two separate purposes - to mark empty ranges (not representing any rows yet) and ranges containing only NULL values. Opclasses don't know which of these cases it is, and so don't know whether to set hasnulls=true. Setting the flag in both cases would make it correct, but it would also make BRIN indexes useless for queries with IS NULL clauses. All ranges start empty (and thus allnulls=true), so all ranges would end up with either allnulls=true or hasnulls=true. The severity of the issue is somewhat reduced by the fact that it only happens when adding values to an existing summary with allnulls=true. This can happen e.g. for small tables (because a summary for the first range exists for all BRIN indexes), or for tables with large fraction of NULL values in the indexed columns. Bulk summarization (e.g. during CREATE INDEX or automatic summarization) that processes all values at once is not affected by this issue. In this case the flags were updated in a slightly different way, not forgetting the NULL values. To identify empty ranges we use a new flag, stored in an unused bit in the BRIN tuple header so the on-disk format remains the same. A matching flag is added to BrinMemTuple, into a 3B gap after bt_placeholder. That means there's no risk of ABI breakage, although we don't actually pass the BrinMemTuple to any public API. We could also skip storing index tuples for empty summaries, but then we'd have to always process such ranges - even if there are no rows in large parts of the table (e.g. after a bulk DELETE), it would still require reading the pages etc. So we store them, but ignore them when building the bitmap. Backpatch to 11. The issue exists since BRIN indexes were introduced in 9.5, but older releases are already EOL. Backpatch-through: 11 Reviewed-by: Justin Pryzby, Matthias van de Meent, Alvaro Herrera Discussion: https://postgr.es/m/402430e4-7d9d-6cf1-09ef-464d80afff3b@enterprisedb.com
* Fix typos in commentsMichael Paquier2023-05-02
| | | | | | | | | The changes done in this commit impact comments with no direct user-visible changes, with fixes for incorrect function, variable or structure names. Author: Alexander Lakhin Discussion: https://postgr.es/m/e8c38840-596a-83d6-bd8d-cebc51111572@gmail.com
* Fix wal_consistency_checking enhanced desc output.Peter Geoghegan2023-04-19
| | | | | | | | | | | | | | | | | | | | Recent enhancements to rmgr desc routines that made the output summarize certain block data (added by commits 7d8219a4 and 1c453cfd) dealt with records that lack relevant block data (and so have nothing to give a more detailed summary of) by testing !DecodedBkpBlock.has_image. As a result, more detailed descriptions of block data were not output when wal_consistency_checking was enabled. This bug affected records with summarizable block data that also happened to have an FPI that the REDO routine isn't supposed to apply (FPIs used for consistency checking purposes only). The presence of such an FPI was incorrectly taken to indicate the absence of block data. To fix, test DecodedBkpBlock.has_data, not !DecodedBkpBlock.has_image. This is the exact condition that we care about, not an inexact proxy. Author: Peter Geoghegan <pg@bowt.ie> Discussion: https://postgr.es/m/CAH2-Wzm5Sc9cBg1qWV_cEBfLNJCrW9FjS-SoHVt8FLA7Ldn8yg@mail.gmail.com
* Remove useless argument from nbtree dedup function.Peter Geoghegan2023-04-18
| | | | | | _bt_dedup_pass()'s heapRel argument hasn't been needed or used since commit cf2acaf4dc made deleting any existing LP_DEAD index tuples the caller's responsibility.
* Fix some typos and some incorrectly duplicated wordsDavid Rowley2023-04-18
| | | | | | Author: Justin Pryzby Reviewed-by: David Rowley Discussion: https://postgr.es/m/ZD3D1QxoccnN8A1V@telsasoft.com
* Fix various typosDavid Rowley2023-04-18
| | | | | | | | | | | | This fixes many spelling mistakes in comments, but a few references to invalid parameter names, function names and option names too in comments and also some in string constants Also, fix an #undef that was undefining the incorrect definition Author: Alexander Lakhin Reviewed-by: Justin Pryzby Discussion: https://postgr.es/m/d5f68d19-c0fc-91a9-118d-7c6a5a3f5fad@gmail.com
* Fix incorrect comment about nbtree WAL record.Peter Geoghegan2023-04-17
| | | | | | | The nbtree VACUUM WAL record stores its page offset number payload in blk 0 (just like the closely related nbtree DELETE WAL record). Commit ebd551f5 fixed a similar issue with the DELETE WAL record, but missed this one.
* Refine the guidelines for rmgrdesc authors.Peter Geoghegan2023-04-11
| | | | | | | | | | | | | | | | Clarify the goals of the recently added guidelines for rmgrdesc authors: to avoid gratuitous inconsistencies across resource managers, and to make it reasonably easy to write a reusable custom parser. Beyond that, the guidelines leave rmgrdesc authors with a significant amount of leeway. This even includes the leeway to invent custom conventions (in cases where it's warranted). Follow-up to commit 7d8219a4. Author: Peter Geoghegan <pg@bowt.ie> Reviewed-By: Melanie Plageman <melanieplageman@gmail.com> Discussion: https://postgr.es/m/CAH2-WzkbYuvwYKm-Y-72QEh6SPMQcAo9uONv+mR3bMGcu9E_Cg@mail.gmail.com
* Fix xl_heap_lock WAL record field's data type.Peter Geoghegan2023-04-11
| | | | | | | | | | | | | | Make xl_heap_lock's infobits_set field of type uint8, not int8. Using int8 isn't appropriate given that the field just holds status bits. This fixes an oversight in commit 0ac5ad5134. In passing rename the nearby TransactionId field to "xmax" to make things consistency with related records, such as xl_heap_lock_updated. Deliberately avoid a bump in XLOG_PAGE_MAGIC. No backpatch, either. Author: Peter Geoghegan <pg@bowt.ie> Discussion: https://postgr.es/m/CAH2-WzkCd3kOS8b7Rfxw7Mh1_6jvX=Nzo-CWR1VBTiOtVZkWHA@mail.gmail.com
* Fix nbtree posting list update desc output.Peter Geoghegan2023-04-10
| | | | | | | | | | | | | | | | | | | | | | | | | We cannot use the generic array_desc approach with per-tuple nbtree posting list update metadata because array_desc can only deal with fixed width elements (e.g., page offset numbers). Using array_desc led to incorrect rmgr descriptions for updates from nbtree DELETE/VACUUM WAL records. To fix, add specialized code to describe the update metadata as array elements in desc output. We now iterate over the update metadata using an approach that matches related REDO routines. Also stop showing the updates offset number array separately in nbtree DELETE/VACUUM desc output. It's redundant information, since the same page offset numbers appear in the description of each individual update element. Also make some small tweaks to the way that we format arrays in all desc routines (not just nbtree desc routines) to make arrays a little less verbose. Oversight in commit 1c453cfd, which enhanced the nbtree rmgr desc routines. Author: Peter Geoghegan <pg@bowt.ie> Discussion: https://postgr.es/m/CAH2-WzkbYuvwYKm-Y-72QEh6SPMQcAo9uONv+mR3bMGcu9E_Cg@mail.gmail.com
* Allow logical decoding on standbysAndres Freund2023-04-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Unsurprisingly, this requires wal_level = logical to be set on the primary and standby. The infrastructure added in 26669757b6a ensures that slots are invalidated if the primary's wal_level is lowered. Creating a slot on a standby waits for a xl_running_xact record to be processed. If the primary is idle (and thus not emitting xl_running_xact records), that can take a while. To make that faster, this commit also introduces the pg_log_standby_snapshot() function. By executing it on the primary, completion of slot creation on the standby can be accelerated. Note that logical decoding on a standby does not itself enforce that required catalog rows are not removed. The user has to use physical replication slots + hot_standby_feedback or other measures to prevent that. If catalog rows required for a slot are removed, the slot is invalidated. See 6af1793954e for an overall design of logical decoding on a standby. Bumps catversion, for the addition of the pg_log_standby_snapshot() function. Author: "Drouvot, Bertrand" <bertranddrouvot.pg@gmail.com> Author: Andres Freund <andres@anarazel.de> (in an older version) Author: Amit Khandekar <amitdkhan.pg@gmail.com> (in an older version) Reviewed-by: Andres Freund <andres@anarazel.de> Reviewed-by: FabrÌzio de Royes Mello <fabriziomello@gmail.com> Reviewed-by: Amit Kapila <amit.kapila16@gmail.com> Reviewed-By: Robert Haas <robertmhaas@gmail.com>
* Show more detail in nbtree rmgr descriptions.Peter Geoghegan2023-04-07
| | | | | | | | | | | | Show a detailed description of the page offset number arrays that appear in certain nbtree WAL records. Also brings nbtree desc routines in line with the guidelines established by recent commit 7d8219a4. Author: Melanie Plageman <melanieplageman@gmail.com> Reviewed-By: Peter Geoghegan <pg@bowt.ie> Discussion: https://postgr.es/m/flat/20230109215842.fktuhesvayno6o4g%40awork3.anarazel.de
* Show more detail in heapam rmgr descriptions.Peter Geoghegan2023-04-07
| | | | | | | | | | | | | | | | | Add helper functions that output arrays in a standard format, and use the functions inside heapdesc routines. This allows tools like pg_walinspect to show a detailed description of the page offset number arrays for records like PRUNE and VACUUM (unless there was an FPI). Also document the conventions that desc routines should follow. Only the heapdesc routines follow the conventions for now, so they're just guidelines for the time being. Based on a suggestion from Andres Freund. Author: Melanie Plageman <melanieplageman@gmail.com> Reviewed-By: Peter Geoghegan <pg@bowt.ie> Discussion: https://postgr.es/m/flat/20230109215842.fktuhesvayno6o4g%40awork3.anarazel.de